@article {lapins_-n2n_2024, title = {DAS-N2N: machine learning distributed acoustic sensing (DAS) signal denoising without clean data}, journal = {Geophysical Journal International}, volume = {236}, number = {2}, year = {2024}, month = {feb}, pages = {1026{\textendash}1041}, abstract = {This paper presents a weakly supervised machine learning method, which we call DAS-N2N, for suppressing strong random noise in distributed acoustic sensing (DAS) recordings. DAS-N2N requires no manually produced labels (i.e. pre-determined examples of clean event signals or sections~of noise) for training and aims to map random noise processes to a chosen summary statistic, such as the distribution mean, median or mode, whilst retaining the true underlying signal. This is achieved by splicing (joining together) two fibres hosted within a single optical cable, recording two noisy copies of the same underlying signal corrupted by different independent realizations of random observational noise. A deep learning model can then be trained using only these two noisy copies of the data to produce a near fully denoised copy. Once the model is trained, only noisy data from a single fibre is required. Using a data set from a DAS array deployed on the surface of the Rutford Ice Stream in Antarctica, we demonstrate that DAS-N2N greatly suppresses incoherent noise and enhances the signal-to-noise ratios (SNR) of natural microseismic icequake events. We further show that this approach is inherently more efficient and effective than standard stop/pass band and white noise (e.g. Wiener) filtering routines, as well as a comparable self-supervised learning method based on masking individual DAS channels. Our preferred model for this task is lightweight, processing 30 s of data recorded at a sampling frequency of 1000~Hz over 985 channels (approximately 1~km of fibre) in \<1~s. Due to the high noise levels in DAS recordings, efficient data-driven denoising methods, such as DAS-N2N, will prove essential to time-critical DAS earthquake detection, particularly in the case of microseismic monitoring.}, issn = {0956-540X}, doi = {10.1093/gji/ggad460}, url = {https://doi.org/10.1093/gji/ggad460}, author = {Lapins, S and Butcher, A and Kendall, J-M and Hudson, T S and Stork, A L and Werner, M J and Gunning, J and Brisbourne, A M} } @article {sato_diel_2024, title = {Diel Vertical Migrators Respond to Short-Term Upwelling Events}, journal = {Geophysical Research Letters}, volume = {51}, number = {2}, year = {2024}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023GL105387}, pages = {e2023GL105387}, abstract = {Pelagic organisms inhabiting coastal upwelling regions face a high risk of advection away from the nearshore productive habitat, potentially leading to mortality. We explored how animals remain in a productive yet highly advective environment in the Northern California Current System using the cabled observatory system located off the Oregon coast. Acoustic scatterers consistent with swimbladder-bearing fish were only present during the downwelling season as these animals avoided the cold waters associated with strong upwelling conditions in summer and fall. Fish responded to short-term upwelling events by increasing the frequency of diel vertical migration. Throughout the study, their vertical positions corresponded to the depth of minimum cross-shelf transport, providing a mechanism for retention. The observed behavioral response highlights the importance of studying ecological processes at short timescales and the abilities of pelagic organisms to control their horizontal distributions through fine-tuned diel vertical migration in response to upwelling.}, keywords = {acoustics, biological-physical interactions, diel vertical migration, Upwelling}, issn = {1944-8007}, doi = {10.1029/2023GL105387}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023GL105387}, author = {Sato, Mei and Benoit-Bird, Kelly J.} } @inbook {aiken_listening_2024, title = {Listening for Diverse Signals From Emergent and Submarine Volcanoes}, booktitle = {Noisy Oceans}, year = {2024}, note = {Section: 4 _eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/9781119750925.ch4}, pages = {43{\textendash}58}, publisher = {American Geophysical Union (AGU)}, organization = {American Geophysical Union (AGU)}, abstract = {Underwater volcanoes produce seismic, tsunami, and volcanic hazards. Yet our first clues regarding underwater volcanism are often limited to observations from satellite imagery or regional seismic networks because of infrequent marine surveys and a limited number of seafloor observatories. On regional networks, large explosions and eruptions can be observed as well as volcanic tremor and magnitude >3 volcano-tectonic earthquakes and very-long-period events, albeit with limited resolution. However, at long distances, other types of signals such as long-period events, explosive-type signals, and landslides may go undetected. Thus there is a need to monitor underwater volcanism locally, to increase observations and enhance their quality and, consequently, sharpen our view of underwater volcanic processes. At present, local deployments of hydrophones and seismometers are rare for underwater volcanoes, perhaps because they seldom present a risk to communities. However, in the future, underwater volcano monitoring may shift toward using existing telecommunication cables. In this chapter, underwater volcano signals are discussed: how they are recorded, detected, monitored, and distinguished in underwater data in the context of known subaerial and submarine volcanism. Examples of known and monitored underwater volcanism are presented as well as economical and environment-friendly real-time submarine volcano monitoring options for the future.}, keywords = {monitoring, submarine volcanoes, volcano seismology, volcano signals}, isbn = {978-1-119-75092-5}, doi = {10.1002/9781119750925.ch4}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/9781119750925.ch4}, author = {Aiken, Chastity} } @article {deshpande_new_2024, title = {A new framework for accessing and visualizing Ocean Color Data for Water quality parameter analysis}, journal = {Journal of Integrated Science and Technology}, volume = {12}, number = {1}, year = {2024}, note = {Number: 1}, pages = {707{\textendash}707}, abstract = {This paper presents a framework for the remote processing and quantitative analysis of water quality parameters, specifically chlorophyll and sea surface temperature (SST). The framework is organized into three directories. The first directory accesses and examines water quality parameters, the second collocates in-situ observations with satellite data, and the third integrates Ocean Observatories Initiative (OOI) data via Machine to Machine (M2M) interfaces. The analysis of chlorophyll concentration is defined in correlation with SST, employing the Gradient of Mean and Mean of Gradient mathematical tools for change detection. The result is a system that leverages cloud technology to access, process, and analyze data. With a spatial gradient tolerance of 90 percentile, the framework enables accurate change detection from time-average data. This methodology contributes to the field of water quality analysis, offering new insights into environmental monitoring and marine science. URN:NBN:sciencein.jist.2024.v12.707}, keywords = {Chlorophyll concentration, Ocean color, remote sensing, Sea surface temperature, Water quality}, issn = {2321-4635}, url = {https://pubs.thesciencein.org/journal/index.php/jist/article/view/a707}, author = {Deshpande, Ashwini and Priyadarshini, Elice and More, Aishwarya and Pate, Shreya} } @article {tang_review_2024, title = {A review of global products of air-sea turbulent heat flux: accuracy, mean, variability, and trend}, journal = {Earth-Science Reviews}, volume = {249}, year = {2024}, pages = {104662}, abstract = {Air-sea turbulent heat flux is vital to the exchange of global water and energy between the atmosphere and the Earth{\textquoteright}s surface and is essential for understanding Earth-climate mutual feedback. In this paper, we comprehensively review the accuracy and spatiotemporal patterns of 15 global products of air-sea turbulent heat flux from 1988 to 2020. Compared to observations at 139 buoys, all the products overestimate monthly latent heat flux (LHF) and most products overestimate sensible heat flux (SHF), with higher correlation coefficients found for LHF than for SHF. Compared to the reanalysis-based and in situ-based products, the remote sensing-based, machine learning-based, and hybrid-based monthly LHF products are generally more consistent with the buoy observations. The annual mean LHF and SHF values vary greatly between 75 and 115~W/m2 and between 0 and 25~W/m2, respectively. Different products have similar spatial patterns of annual means and interannual variabilities of LHF and SHF in most ocean areas but they have very different magnitudes. Most products show consistent annual trends in LHF and consistent but overall weaker annual trends in SHF, except for in the areas around and beyond 45{\textdegree}S, where larger discrepancies in annual SHF trends are observed. Analogous unimodal shapes of monthly SHF frequency curves from the 15 products are shown in all oceans, but for the monthly LHF frequency curves, both unimodal and bimodal shapes are shown. Seasonal LHF and SHF values are higher (lower) in December{\textendash}January-February than in June{\textendash}July-August in the Northern (Southern) Hemisphere. The interseasonal variations in LHF and SHF are more pronounced in the Northern Hemisphere than in the Southern Hemisphere. This review could benefit the algorithm development and improvement of air-sea turbulent heat flux products, provide insightful scientific guidance for selecting flux products for different applications, and characterize the advances in the global datasets of air-sea turbulent heat flux.}, keywords = {Air-sea turbulent heat flux, latent heat flux, Sensible heat flux, Trend, Variability}, issn = {0012-8252}, doi = {10.1016/j.earscirev.2023.104662}, url = {https://www.sciencedirect.com/science/article/pii/S0012825223003513}, author = {Tang, Ronglin and Wang, Yizhe and Jiang, Yazhen and Liu, Meng and Peng, Zhong and Hu, Yongxin and Huang, Lingxiao and Li, Zhao-Liang} } @article {arango_4d-var_2023, title = {4D-Var data assimilation in a nested model of the Mid-Atlantic Bight}, journal = {Ocean Modelling}, volume = {184}, year = {2023}, pages = {102201}, abstract = {The Regional Ocean Modeling System (ROMS) 4-dimensional variational (4D-Var) data assimilation platform has been extended to include nested grid configurations using both one-way and two-way nesting strategies. The efficacy of this new ROMS utility is demonstrated in a model comprising three nested grids with horizontal refinement and configured for the Mid-Atlantic Bight. The three nested grids have a horizontal resolution ranging from \~{}7 km to \~{}0.8 km thereby capturing circulation regimes that span the Gulf Stream western boundary current, through the mesoscale eddy field, and down to the rapidly evolving and energetic submesoscale. These circulation regimes represent a challenge for any data assimilation system, and the nested 4D-Var system was found to perform well across the range of resolved space and time scales. The observational data used to constrain the ocean state estimates come from a wide range of remote sensing, in situ, and mobile platforms, along with the U.S. National Science Foundation{\textquoteright}s Ocean Observatories Initiative Pioneer Array. Several aspects of the system performance are explored and described here, including the fit of the model to the observations, the influence of data assimilation on the wave number spectra at the submesoscale, and the downscaling and upscaling of information captured by the observations.}, keywords = {4D-Var, Data assimilation, Mid-Atlantic Bight, Nested grids, Pioneer Array}, issn = {1463-5003}, doi = {10.1016/j.ocemod.2023.102201}, url = {https://www.sciencedirect.com/science/article/pii/S1463500323000422}, author = {Arango, Hernan G. and Levin, Julia and Wilkin, John and Moore, Andrew M.} } @article {ferguson_acoustic_2023, title = {Acoustic indices respond to specific marine mammal vocalizations and sources of anthropogenic noise}, journal = {Frontiers in Marine Science}, volume = {10}, year = {2023}, abstract = {Using passive acoustic methods for biodiversity conservation and effective ecosystem monitoring is hindered by laborious, human-mediated processes of accurately identifying biologic and anthropogenic sounds within large datasets. Soundscape ecology provides a potential means of addressing this need through the use of automated acoustic-based biodiversity indices, which show promise in representing biodiversity in terrestrial environments. However, the direct relationship between specific underwater sounds and acoustic index measurements are largely unexplored. Using passive acoustic data collected from three broadband hydrophones within the Ocean Observatories Initiative{\textquoteright}s cabled arrays in the Pacific northwest, we identified periods of vocalizing marine mammals and sources of anthropogenic noise. Automated calculations of seven acoustic indices were compared across biologic and anthropogenic sound type and call parameters. Although several index measurements did not vary significantly, the Acoustic Complexity Index (ACI) measurements increased in response to echolocation clicks from sperm whales (Physeter macrocephalus) and burst pulses originating from unidentified delphinid species. Measurements of the Bioacoustic Index (BI) decreased dramatically in response to sperm whale echolocation clicks, a more obvious trend when loud clicks were parsed from moderate and quiet clicks. Correlations coefficient and confidence interval values between ACI and BI measurements and call characteristics from sperm whales indicate a moderate to strong relationship, which was not found in correlations with delphinid calls. A generalized linear mixed-effect model indicated multiple species and sound types contribute significantly to the variation of several index measurements. Noise generated by passing ships consistently resulted in decreased values for the Normalized Difference Soundscape Index (NDSI) and Total Entropy (H) as compared to quiet periods and periods with vocalizing marine mammals. These findings provide information on the relationship between several acoustic indices and specific underwater sounds produced by marine mammals and anthropogenic sources. This ground-truthing endeavor expands the understanding of acoustic indices and their potential use as a tool for conservation and ecosystem health management purposes.}, issn = {2296-7745}, doi = {10.3389/fmars.2023.1025464}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2023.1025464}, author = {Ferguson, Elizabeth L. and Clayton, Hannah M. and Sakai, Taiki} } @article {terwilliger_age_2023, title = {Age validation of Black Rockfish, Copper Rockfish, and Cabezon using secondary ion mass spectrometry (SIMS) to elucidate seasonal patterns in otolith stable oxygen isotopes}, journal = {Environmental Biology of Fishes}, volume = {106}, number = {3}, year = {2023}, month = {mar}, pages = {553{\textendash}573}, abstract = {Stock assessors commonly use models that incorporate biological data such as fish length and age to determine the status of fish stocks and how different management scenarios affect stock size. Ages used in assessment models need to be accurate and precise because ageing error can affect many model inputs and potentially result in stock mismanagement. Despite the requirement for sound age data, few studies have investigated accuracy of ages for groundfish captured in coastal nearshore waters off Oregon, USA. In this study, we validate otolith ages for Black Rockfish (Sebastes melanops), Copper Rockfish (Sebastes caurinus) and Cabezon (Scorpaenichthys marmoratus), three species with recreational and commercial importance to Oregon. Ages obtained by traditional break-and-burn methods were validated using secondary ion mass spectrometry (SIMS) to examine otolith stable oxygen isotope ratios (δ18O) over a fish{\textquoteright}s lifetime. This technique relies on the inverse relationship that exists between otolith δ18O and ambient water temperature, and independent counts of δ18O maxima should be comparable to ages obtained by visual counts of otolith growth marks laid down during cold water periods. Locations of δ18O maxima in otolith chronologies matched well with locations of visual growth marks in otoliths of all three species, maxima counts were strongly positively correlated with age, and variation in otolith δ18O decreased with age. However, significant variability in the δ18O chronologies caused by variability in intra-seasonal upwelling and resulting water temperature variations made maxima counts difficult in several samples. Correct interpretation of chronologies required knowledge of location of the first annulus, the compression of growth zones with age, and an assumption of the seasonal amplitude of the ambient water δ18O.}, keywords = {Groundfish, Otoliths, Oxygen isotopes, Upwelling, Validation}, issn = {1573-5133}, doi = {10.1007/s10641-023-01392-3}, url = {https://doi.org/10.1007/s10641-023-01392-3}, author = {Terwilliger, Mark R. and Rasmuson, Leif K. and Stern, Richard A.} } @article {srokosz_atlantic_2023, title = {Atlantic overturning: new observations and challenges}, journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences}, volume = {381}, number = {2262}, year = {2023}, note = {Publisher: Royal Society}, month = {oct}, pages = {20220196}, abstract = {This paper provides an introduction to the special issue of the Philosophical Transactions of the Royal Society of London of papers from the 2022 Royal Society meeting on {\textquoteleft}Atlantic overturning: new observations and challenges{\textquoteright}. It provides the background and rationale for the meeting, briefly summarizes prior progress on observing the Atlantic overturning circulation and draws out the new challenges that papers presented at the meeting raise, so pointing the way forward for future research. This article is part of a discussion meeting issue {\textquoteright}Atlantic overturning: new observations and challenges{\textquoteright}.}, keywords = {AMOC, Atlantic, observations, OSNAP, overturning circulation, RAPID}, doi = {10.1098/rsta.2022.0196}, url = {https://royalsocietypublishing.org/doi/10.1098/rsta.2022.0196}, author = {Srokosz, Meric A. and Holliday, N. Penny and Bryden, Harry L.} } @article {bane_atmospheric_2023, title = {Atmospheric forcing of the Hatteras coastal ocean during 2017-2018: The PEACH program}, journal = {Dynamics of Atmospheres and Oceans}, year = {2023}, month = {mar}, pages = {101364}, abstract = {The Hatteras coastal ocean is centrally located along the east coast of the 48 contiguous United States, offshore of Cape Hatteras in a complex land/ocean/atmosphere region where major ocean currents of differing temperatures and salinities meet and interact, where the atmosphere fluctuates on a wide range of time scales, and where atmosphere-ocean interactions vary both spatially and temporally. The Gulf Stream current typically leaves its contact with the continental margin here. Continental shelf currents from the north and from the south converge here, resulting in a net shelf-to-ocean transport of shelf waters that carry important water properties and constituents. The two major drivers of these shelf currents and exchanges are the atmosphere and the oceanic Gulf Stream. Atmospheric driving of the Hatteras coastal ocean is through surface wind stress and heat flux across the air-sea interface. The complexity and importance of this region motivated the NSF-sponsored PEACH research program during 2017-2018 (PEACH: Processes driving Exchange At Cape Hatteras). In this paper, we utilize the substantial number of observations available during PEACH to describe the atmospheric forcing of the ocean then. Atmospheric conditions are described in terms of two seasons: the warm season (May to mid-September), with predominantly mild northeastward winds punctuated by occasional tropical cyclones (TCs); and the cool season (mid-September through April), with a nearly continuous, northeastward progression of energetic extratropical cyclones (ETCs) through the region. Cool season ETCs force the region with strong wind stress and ocean-to-atmosphere heat flux episodes, each with a time-scale of several days. Wind stress fluctuation magnitudes typically exceed mean stress magnitudes in each season by a factor of 3 to 5. These stresses account for just over 40\% of the total current variability in the region, showing the wind to be a major driver of the ocean here. Atmosphere-ocean heat flux is typically into the ocean throughout the warm season (\textasciitilde100Wm-2); it is essentially always out of the ocean during the cool season (\textasciitilde500Wm-2 or more). New results herein include: southward intraseasonal oscillations of the jet stream{\textquoteright}s position drove the strongest ETCs (including one {\textquotedblleft}bomb{\textquotedblright} cyclone); and during the 41 years leading up to and including PEACH, the season-averaged number and strength of atmospheric cyclones passing over the Hatteras coastal ocean have shown little long-term change. Looking ahead, the NSF Pioneer Array is scheduled to be relocated to the northern portion of the Hatteras coastal ocean in 2024, and the NASA SWOT satellite has begun its ocean topography mission, which has a ground-track cross-over here.}, keywords = {atmospheric cyclones, Atmospheric forcing, atmospheric warm and cool seasons, Cape Hatteras, PEACH}, issn = {0377-0265}, doi = {10.1016/j.dynatmoce.2023.101364}, url = {https://www.sciencedirect.com/science/article/pii/S0377026523000155}, author = {Bane, John and Seim, Harvey and Haines, Sara and Han, Lu and He, Ruoying and Zambon, Joseph} } @article {gemba_basin_2023, title = {Basin scale coherence of Kauai-Beacon m-sequence transmissions received at Wake Island and Monterey, CA}, journal = {JASA Express Letters}, volume = {3}, number = {8}, year = {2023}, pages = {080801}, abstract = {The 75 Hz Kauai-Beacon source is well-situated for observing the North Pacific Ocean acoustically, and ongoing efforts enable transmissions and analysis of broadband signals in 2023 and beyond. This is the first demonstration of acoustic receiving along paths to Wake Island (\~{}3500 km) and Monterey Bay (\~{}4000 km). The 44 received m-sequence waveforms exhibit excellent phase stability with processing gain approaching the maximum theoretical gain evaluated over the 20 min signal transmission duration. The article concludes with a discussion on the future source utility and highlights research topics of interest, including observed Doppler (waveform dilation), thermometry, and tomography.}, issn = {2691-1191}, doi = {10.1121/10.0020514}, url = {https://doi.org/10.1121/10.0020514}, author = {Gemba, Kay L. and Durofchalk, Nicholas C. and Dall{\textquoteright}Osto, David R. and Andrew, Rex K. and Leary, Paul and Howe, Bruce M. and Smith, Kevin B.} } @book {manson_big_2023, title = {Big Data and Human-Environment Systems}, year = {2023}, note = {Google-Books-ID: GV6lEAAAQBAJ}, month = {jan}, publisher = {Cambridge University Press}, organization = {Cambridge University Press}, abstract = {Transformation of the Earth{\textquoteright}s social and ecological systems is occurring at a rate and magnitude unparalleled in human experience. Data science is a revolutionary new way to understand human-environment relationships at the heart of pressing challenges like climate change and sustainable development. However, data science faces serious shortcomings when it comes to human-environment research. There are challenges with social and environmental data, the methods that manipulate and analyze the information, and the theory underlying the data science itself; as well as significant legal, ethical and policy concerns. This timely book offers a comprehensive, balanced, and accessible account of the promise and problems of this work in terms of data, methods, theory, and policy. It demonstrates the need for data scientists to work with human-environment scholars to tackle pressing real-world problems, making it ideal for researchers and graduate students in Earth and environmental science, data science and the environmental social sciences.}, keywords = {Business \& Economics / Environmental Economics, Law / Environmental, Nature / Environmental Conservation \& Protection, Science / Environmental Science, Technology \& Engineering / Environmental / General}, isbn = {978-1-108-48628-6}, author = {Manson, Steven M.} } @article {roberts_blueprint_2023, title = {A blueprint for integrating scientific approaches and international communities to assess basin-wide ocean ecosystem status}, journal = {Communications Earth \& Environment}, volume = {4}, number = {1}, year = {2023}, note = {Number: 1 Publisher: Nature Publishing Group}, month = {jan}, abstract = {Ocean ecosystems are at the forefront of the climate and biodiversity crises, yet we lack a unified approach to assess their state and inform sustainable policies. This blueprint is designed around research capabilities and cross-sectoral partnerships. We highlight priorities including integrating basin-scale observation, modelling and genomic approaches to understand Atlantic oceanography and ecosystem connectivity; improving ecosystem mapping; identifying potential tipping points in deep and open ocean ecosystems; understanding compound impacts of multiple stressors including warming, acidification and deoxygenation; enhancing spatial and temporal management and protection. We argue that these goals are best achieved through partnerships with policy-makers and community stakeholders, and promoting research groups from the South Atlantic through investment and engagement. Given the high costs of such research ({\texteuro}800k to {\texteuro}1.7M per expedition and {\texteuro}30{\textendash}40M for a basin-scale programme), international cooperation and funding are integral to supporting science-led policies to conserve ocean ecosystems that transcend jurisdictional borders.}, keywords = {Marine biology, physical oceanography}, issn = {2662-4435}, doi = {10.1038/s43247-022-00645-w}, url = {https://www.nature.com/articles/s43247-022-00645-w}, author = {Roberts, J. Murray and Devey, Colin W. and Biastoch, Arne and Carreiro-Silva, Marina and Dohna, Tina and Dorschel, Boris and Gunn, Vikki and Huvenne, Veerle A. I. and Johnson, David and Jollivet, Didier and Kenchington, Ellen and Larkin, Kate and Matabos, Marjolaine and Morato, Telmo and Naumann, Malik S. and Orejas, Covadonga and Perez, J. Angel A. and Ragnarsson, Stef{\'a}n {\'A} and Smit, Albertus J. and Sweetman, Andrew and Unger, Sebastian and Boteler, Benjamin and Henry, Lea-Anne} } @article {buckley_buoyancy_2023, title = {Buoyancy forcing and the subpolar Atlantic meridional overturning circulation}, journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences}, volume = {381}, number = {2262}, year = {2023}, note = {Publisher: Royal Society}, month = {oct}, pages = {20220181}, abstract = {The North Atlantic meridional overturning circulation and its variability are examined in terms of the overturning in density space and diapycnal water mass transformation. The magnitude of the mean overturning is similar to the surface water mass transformation, but the density and properties of these waters are modified by diapycnal mixing. Surface waters are progressively densified while circulating cyclonically around the subpolar gyre, with the densest waters and deepest convection occurring in the Labrador Sea and Nordic Seas. The eddy-driven interaction between the convective interior and boundary currents is a key to the export of dense waters from marginal seas. Due to the multitude of pathways of dense waters within the subpolar gyre, as well as mixing with older waters, waters exiting the subpolar gyre have a wide range of ages, with a mean age on the order of a decade. As a result, interannual changes in water mass transformation are mostly balanced locally and do not result in changes in export to the subtropics. Only persistent changes in water mass transformation result in changes in export to the subtropics. The dilution of signals from upstream water mass transformation suggests that variability in export of dense waters to the subtropics may be controlled by other processes, including interaction of dense waters with the energetic upper ocean. This article is part of a discussion meeting issue {\textquoteleft}Atlantic overturning: new observations and challenges{\textquoteright}.}, keywords = {Atlantic Meridional Overturning Circulation, buoyancy forcing, water mass transformation}, doi = {10.1098/rsta.2022.0181}, url = {https://royalsocietypublishing.org/doi/10.1098/rsta.2022.0181}, author = {Buckley, Martha W. and Lozier, M. Susan and Desbruy{\`e}res, Damien and Evans, Dafydd Gwyn} } @article {cook_calibrated_2023, title = {Calibrated Absolute Seafloor Pressure Measurements for Geodesy in Cascadia}, journal = {Journal of Geophysical Research: Solid Earth}, volume = {128}, number = {6}, year = {2023}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023JB026413}, pages = {e2023JB026413}, abstract = {The boundary between the overriding and subducting plates is locked along some portions of the Cascadia subduction zone. The extent and location of locking affects the potential size and frequency of great earthquakes in the region. Because much of the boundary is offshore, measurements on land are incapable of completely defining a locked zone in the up-dip region. Deformation models indicate that a record of seafloor height changes on the accretionary prism can reveal the extent of locking. To detect such changes, we have initiated a series of calibrated pressure measurements using an absolute self-calibrating pressure recorder. A piston-gauge calibrator under careful metrological considerations produces an absolutely known reference pressure to correct seafloor pressure observations to an absolute value. We report an accuracy of about 25 ppm of the water depth, or 0.02 kPa (0.2 cm equivalent) at 100 m to 0.8 kPa (8 cm equivalent) at 3,000 m. These campaign survey-style absolute pressure measurements on seven offshore benchmarks in a line extending 100 km westward from Newport, Oregon from 2014 to 2017 establish a long-term, sensor-independent time series that can, over decades, reveal the extent of vertical deformation and thus the extent of plate locking and place initial limits on rates of subsidence or uplift. Continued surveys spanning years could serve as calibration values for co-located or nearby continuous pressure records and provide useful information on possible crustal deformation rates, while epoch measurements spanning decades would provide further limits and additional insights on deformation.}, keywords = {absolute pressure, calibrated pressure, Cascadia subduction zone, marine geophysics, piston gauge calibrator, seafloor geodesy}, issn = {2169-9356}, doi = {10.1029/2023JB026413}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JB026413}, author = {Cook, Matthew J. and Fredrickson, Erik K. and Roland, Emily C. and Sasagawa, Glenn S. and Schmidt, David A. and Wilcock, William S. D. and Zumberge, Mark A.} } @article {lobert_categorization_2023, title = {Categorization of High-Wind Events and Their Contribution to the Seasonal Breakdown of Stratification on the Southern New England Shelf}, journal = {Journal of Geophysical Research - Oceans}, year = {2023}, note = {Publisher: American Geophysical Union (AGU)}, month = {jun}, pages = {e2022JC019625}, abstract = {High-wind events predominantly cause the rapid breakdown of seasonal stratification on the continental shelf by the end of October. In particular the timing of events leads to considerable interannual variability in the stratification breakdown with a standard deviation of 15 days. Although previous studies have shown how coastal stratification depends on local wind-forcing characteristics, the locally observed ocean forcing has not yet been linked to regional atmospheric weather patterns that determine the local wind characteristics. Establishing such a connection is a necessary first step toward examining how an altered atmospheric forcing due to climate change affects coastal ocean conditions. Here, we propose a categorization scheme for high-wind events that links atmospheric forcing patterns with changes in stratification. We apply the scheme to the Southern New England shelf utilizing observations from the Ocean Observatories Initiative Coastal Pioneer Array (2015{\textendash}2022). Impactful wind forcing patterns occur predominantly during early fall, have strong downwelling-favorable winds, and are primarily of two types: (a) Cyclonic storms that propagate south of the continental shelf causing anticyclonically rotating winds, and (b) persistent large-scale high-pressure systems over East Canada causing steady north-easterly winds. These patterns are associated with opposite temperature and salinity contributions to destratification, implying differences in the dominant processes driving ocean mixing based on a high-wind pattern{\textquoteright}s overall strength and wind direction steadiness. The high-wind event categorization scheme allows a transition from solely focusing on local wind forcing to considering realistic atmospheric weather patterns when investigating their impact on stratification in the coastal ocean.}, keywords = {13 Climate Action, continental shelf, destratification, OOI Coastal Pioneer, storm categorization, stratification breakdown, synoptic meteorology}, issn = {2169-9275}, doi = {10.1029/2022jc019625}, author = {Lobert, L and Gawarkiewicz, G and Plueddemann, A} } @article {cheng_characterizing_2023, title = {Characterizing the Effect of Ocean Surface Currents on Advanced Scatterometer (ASCAT) Winds Using Open Ocean Moored Buoy Data}, journal = {Remote Sensing}, volume = {15}, number = {18}, year = {2023}, note = {Number: 18 Publisher: Multidisciplinary Digital Publishing Institute}, pages = {4630}, abstract = {The ocean surface current influences the roughness of the sea surface, subsequently affecting the scatterometer{\textquoteright}s measurement of wind speed. In this study, the effect of surface currents on ASCAT-retrieved winds is investigated based on in-situ observations of both surface winds and currents from 40 open ocean moored buoys in the tropical and mid-latitude oceans. A total of 28,803 data triplets, consisting of buoy-observed wind vectors, current vectors, and ASCAT Level 2 wind vectors, were collected from the dataset spanning over 10 years. It is found that the bias between scatterometer-retrieved wind speed and buoy-observed wind speed is negatively correlated with the ocean surface current speed. The wind speed bias is approximately 0.96 times the magnitude of the downwind surface current. The root-mean-square error between the ASCAT wind speeds and buoy observations is reduced by about 15\% if rectification with ocean surface currents is involved. Therefore, it is essential to incorporate surface current information into wind speed calibration, particularly in regions with strong surface currents.}, keywords = {ASCAT, moored buoys, ocean surface current, sea surface wind}, issn = {2072-4292}, doi = {10.3390/rs15184630}, url = {https://www.mdpi.com/2072-4292/15/18/4630}, author = {Cheng, Tianyi and Chen, Zhaohui and Li, Jingkai and Xu, Qing and Yang, Haiyuan} } @article {josey_clearer_2023, title = {A clearer view of Southern Ocean air{\textendash}sea interaction using surface heat flux asymmetry}, journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences}, volume = {381}, number = {2249}, year = {2023}, note = {Publisher: Royal Society}, month = {may}, pages = {20220067}, abstract = {Progress in understanding Southern Ocean heat exchange and wind forcing is discussed and new results presented. These include a metric of the zonal asymmetry between surface ocean heat gain in the Atlantic/Indian sector and heat loss in the Pacific sector. The asymmetry arises from an intersector variation in the humidity gradient between the sea surface and near-surface atmosphere. This gradient increases by 60\% in the Pacific sector enabling a 20 Wm-2 stronger latent heat loss compared with the Atlantic/Indian sector. The new metric is used for intercomparison of atmospheric reanalyses and CMIP6 climate simulations. CMIP6 has weaker Atlantic/Indian sector heat gain compared with the reanalyses primarily due to Indian Ocean sector differences. The potential for surface flux buoys to provide an observation-based counterpart to the asymmetry metric is explored. Over the past decade, flux buoys have been deployed at two sites (south of Tasmania and upstream of Drake Passage). The data record provided by these moorings is assessed and an argument developed for a third buoy to sample the Atlantic/Indian sector of the asymmetry metric. To close, we assess evidence that the main westerly wind belt has strengthened and moved southward in recent decades using the ERA5 reanalysis. This article is part of a discussion meeting issue {\textquoteright}Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities{\textquoteright}.}, keywords = {air{\textendash}sea heat flux, Southern Ocean, wind stress}, doi = {10.1098/rsta.2022.0067}, url = {https://royalsocietypublishing.org/doi/full/10.1098/rsta.2022.0067}, author = {Josey, Simon A. and Grist, Jeremy P. and Mecking, Jennifer V. and Moat, Ben I. and Schulz, Eric} } @article {wang_constrained_2023, title = {A constrained engineering design method for constant-current remote power supply system of mesh-type cabled underwater information networks}, journal = {Energy Reports}, volume = {9}, year = {2023}, pages = {2525{\textendash}2537}, abstract = {Remote power supply technology is critical for the long-term, wide-area, and real-time monitoring of marine data in cabled underwater information networks (CUINs). In this study, the constant-current remote power supply system (CCRPSS) of mesh-type CUINs based on constant-current branch equipment (CCBE) and constant-current/constant-voltage conversion equipment (CCVE) is studied. The system can be categorized into various power supply links and link segments according to the current flow path and structural characteristics. A system basic simulation model is designed to analyze the influence of 11 typical faults on the working state of the system and to summarize the influence of the open-circuit/short-circuit faults of various underwater units in different power supply link segments on the working state of the system. Then the analysis method of power supply reliability (PSR) of the observation equipment (OE) is proposed. The PSR of the OE of the same power supply link (PSL) decreases gradually from shore to sea, and the PSR of the OE located at the center of the PSL is the lowest in the regular deployment of the CCRPSS. To increase the number of nodes deployed and to reduce the total cost, an engineering design method for the system that integrates the constraints of the PSR of the OE, the fault rate of the underwater unit, and the number of second nodes of each power supply link segment (PSLS) is proposed based on invasive weed optimization (IWO). Through the example simulation, the results of the system cost, the deployment number of secondary nodes, and the reliability of the underwater units are obtained, which also confirms that the PSR of the OE located at the center of the PSL is the lowest. This method can be effectively applied to the engineering design of CCRPSS and can provide theoretical and technical support for future large-scale CUINs construction.}, keywords = {Cabled underwater information networks (CUINs), Constant-current remote power supply system (CCRPSS), Constraint engineering design, Mesh-type, Open-circuit/short-circuit fault, Reliability}, issn = {2352-4847}, doi = {10.1016/j.egyr.2023.01.101}, url = {https://www.sciencedirect.com/science/article/pii/S2352484723001099}, author = {Wang, Xichen and Qiao, Xiaorui and Zhou, Xuejun} } @article {torabi_covering_2023, title = {Covering tour problem with varying coverage: Application to marine environmental monitoring}, journal = {Applied Mathematical Modelling}, volume = {124}, year = {2023}, pages = {279{\textendash}299}, abstract = {In this paper, we present a novel variant of the Covering Tour Problem (CTP), called the Covering Tour Problem with Varying Coverage (CTP-VC). We consider a simple graph G=(V,E), with a measure of importance assigned to each node in V. A vehicle with limited battery capacity visits the nodes of the graph and has the ability to stay in each node for a certain period of time, which determines the coverage radius at the node. We refer to this feature as stay-dependent varying coverage or, in short, varying coverage. The objective is to maximize a scalarization of the weighted coverage of the nodes and the negation of the cost of moving and staying at the nodes. This problem arises in the monitoring of marine environments, where pollutants can be measured at locations far from the source due to ocean currents. To solve the CTP-VC, we propose a mathematical formulation and a heuristic approach, given that the problem is NP-hard. Depending on the availability of solutions yielded by an exact solver, we evaluate our heuristic approach against the exact solver or a constructive heuristic on various instance sets and show how varying coverage improves performance. Additionally, we use an offshore CO2 storage site in the Gulf of Mexico as a case study to demonstrate the problem{\textquoteright}s applicability. Our results demonstrate that the proposed heuristic approach is an efficient and practical solution to the problem of stay-dependent varying coverage. We conduct numerous experiments and provide managerial insights.}, keywords = {Covering tour problem, Heuristics, Marine monitoring, Mathematical modeling, Offshore carbon capture and storage}, issn = {0307-904X}, doi = {10.1016/j.apm.2023.07.024}, url = {https://www.sciencedirect.com/science/article/pii/S0307904X23003281}, author = {Torabi, Parisa and Oleynik, Anna and Hemmati, Ahmad and Alendal, Guttorm} } @article {zhang_cross-shelf_2023, title = {Cross-shelf exchange associated with a shelf-water streamer at the Mid-Atlantic Bight shelf edge}, journal = {Progress in Oceanography}, volume = {210}, year = {2023}, month = {jan}, pages = {102931}, abstract = {Significant exchanges between the Mid-Atlantic Bight (MAB) continental shelf and the neighboring open ocean can be induced by shelf water streamers, submesoscale filaments of shelf water entrained into the open ocean by Gulf Stream warm-core rings (WCRs) impinging onto the MAB continental shelf. Shelf water streamers have distinctive surface temperature and chlorophyll signals, and are thus visible from space. Satellite-measured sea surface height, temperature and chlorophyll show the evolution of a WCR over its 6-month lifespan in February-August 2019 and the persistent shelf water streamer it generated on its outskirt. In situ measurements from a two-week cruise in July 2019 were analyzed to investigate the physical, biological and biogeochemical characteristics of the shelf water streamer below the surface, and to quantify the associated cross-shelf transport of volume, heat, salt, carbon and oxygen. The analyses demonstrated that offshore transport of shelf water by the streamer, which was presumably balanced by either onshore intrusion of ring water or enhanced transport of shelf water from upstream, represented a major form of exchange between the MAB continental shelf and the open ocean. The streamer caused significant net onshore transport of heat and salt, and a significant net offshore transport of organic carbon and oxygen. Primary productivity in the streamer was higher than the surrounding slope and ring waters on the surface, which likely resulted from subsurface nutrients in the offshore-flowing shelf water being gradually consumed as the overlying water became clearer. WCR-induced shelf water streamers thus enhanced surface biological productivity in the slope sea. Plain Language Summary: Waters of the shallow Mid-Atlantic Bight continental shelf and the neighboring deep slope sea have distinctly different physical, biological and chemical properties. Mixing between them can affect the shelf ecosystem and the dispersal of coastal materials into the deep ocean. One type of cross-shelf-edge mixing process results from strong clockwise-rotating vortices {\textendash} so-called warm-core rings {\textendash} formed from meanders of the Gulf Stream. As a warm-core ring intrudes onto the shelf edge, it often draws shelf water offshore, forming a thin filament in the slope sea. This filament is called a shelf-water streamer and has distinctive surface temperature and chlorophyll signals that are visible from space. Warm-core rings can also push offshore water onto the shallow shelf. This study examines the evolution of a warm-core ring over its 6-month lifespan in 2019 and the shelf-water streamer the ring induced in 5 of the 6~months. Interdisciplinary measurements from a field expedition in July 2019 were examined to assess the subsurface patterns of the streamer and to quantify the induced cross-shelf fluxes of heat, salt, organic carbon and oxygen. The analysis showed that the streamer represented a major form of cross-shelf mixing and caused a substantial onshore transport of heat and salt, as well as a substantial offshore transport of organic carbon and oxygen.}, keywords = {carbon flux, Cross-shelf exchange, Heat flux, Primary productivity, Salt flux, Shelf-water streamer, Warm-core ring}, issn = {0079-6611}, doi = {10.1016/j.pocean.2022.102931}, url = {https://www.sciencedirect.com/science/article/pii/S0079661122001902}, author = {Zhang, Weifeng (Gordon) and Alatalo, Philip and Crockford, Taylor and Hirzel, Andrew J. and Meyer, Meredith G. and Oliver, Hilde and Peacock, Emily and Petitpas, Christian M. and Sandwith, Zoe and Smith, Walker O. and Sosik, Heidi M. and Stanley, Rachel H. R. and Stevens, Bethany L. F. and Turner, Jefferson T. and McGillicuddy, Dennis J.} } @inbook {sun_data_2023, title = {Data Foundation for Actionable Science}, booktitle = {Actionable Science of Global Environment Change: From Big Data to Practical Research}, year = {2023}, pages = {31{\textendash}54}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {The field of climate and environmental research heavily~relies on scientific data to understand the complex interactions between the Earth{\textquoteright}s systems and the impacts of human activities. High-quality data is critical to informing evidence-based policies and decision-making that address global environmental challenges. This chapter discusses the importance of a robust data foundation for actionable science within the realm of global environmental change. It~overviews the historical transformation of climate research, highlighting the growing significance of data in the field. It then delves into the various types of scientific data, including observational data, remote sensing data, and model output data. The chapter further examines the challenges and limitations associated with these data types, such as data quality, availability, and accessibility. Furthermore, it highlights the importance of data management and sharing practices to promote open and reproducible science. It also discusses emerging data technologies and trends, such as big data and machine learning, and their potential applications in climate and environmental research.}, keywords = {Data management, Data science, Environment science}, isbn = {978-3-031-41758-0}, doi = {10.1007/978-3-031-41758-0_2}, url = {https://doi.org/10.1007/978-3-031-41758-0_2}, author = {Sun, Ziheng}, editor = {Sun, Ziheng} } @article {zou_deep_2023, title = {Deep Ocean Circulation in the Subpolar North Atlantic Observed by Acoustically-tracked Floats}, journal = {Progress in Oceanography}, volume = {211}, year = {2023}, month = {jan}, pages = {102975}, abstract = {The deep circulation in the subpolar North Atlantic determines the spread and mixing of high latitude climate signals to lower latitudes. However, our current understanding of the subpolar deep circulation has been limited due to relatively sparse observational data. To improve that understanding, we construct gridded fields of mean velocity and eddy kinetic energy (EKE) in the deep (1800-2800 dbar) subpolar North Atlantic using direct velocity measurements from 122 subsurface acoustically-tracked floats that drifted during June 2014 {\textendash} January 2019. The mean velocity field reveals a relatively strong deep boundary current around Greenland and in the Labrador Sea, with a weaker deep boundary current over the eastern flank of the Reykjanes Ridge, and near-zero mean flow over the western flank, implying a discontinuous deep boundary current across the subpolar basin. The deep EKE, albeit with smaller magnitudes, generally resembles the EKE pattern at the ocean surface, including relatively high values along pathways of the North Atlantic Current and west of Greenland where the Irminger Rings are formed. A surprising finding about deep EKE is an elevated band east of Greenland that parallels the coast and is not present in the surface EKE field. This high EKE band is possibly attributed to the combined influence from propagating Denmark Strait Overflow Cyclones, variability of the wind-driven recirculation offshore of southeast Greenland, and/or topographic waves. The float-based flow fields constructed in this study provide an unprecedented quantitative view of the kinematic properties of the large-scale deep circulation in the subpolar North Atlantic. Combined with cross-basin Eulerian measurements, we believe these recent observations provide a benchmark for testing and improving numerical simulations of deep ocean circulation and the Meridional Overturning Circulation, which are urgently needed for climate change predictions.}, keywords = {Lagrangian float observations, North Atlantic deep eddy kinetic energy, North Atlantic deep ocean circulation, Overflow water pathways}, issn = {0079-6611}, doi = {10.1016/j.pocean.2023.102975}, url = {https://www.sciencedirect.com/science/article/pii/S0079661123000186}, author = {Zou, Sijia and Bower, Amy S. and Susan Lozier, M. and Furey, Heather} } @article {zhang_design_2023, title = {Design and optimization of buoy mooring with single-point cable for seafloor observatories}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2023}, abstract = {For long-term mooring buoy observatories in the deep sea far from the coasts, we design the hybrid system, named Mooring Buoys Observation System with Benthic Electro-optical-mechanical Cable (MBOSBC). The Electro Optical Mechanical (EOM) cable connects the sea surface buoy, and benthic observation node, as the transmission link of information and power. Different from the traditional buoy mooring, Mooring Buoys Observation System needs to accomplish the energy and data transmission between the seabed and the sea surface. The EOM cable is utilized for mooring, and it is the crucial link to ensure the long-term and effective work of the system and energy / data transmission. EOM cable plays the role of mooring tether of MBOSBC. Since the EOM cable has to experience higher loads under most environmental conditions for long terms. It is often happened that, the EOM cable is not broken, but the power supply core wire and signal wire have broken or failed, while the buoy is subjected to wind, wave and current load. This puts forward the requirements for the design of bearing load and mooring style for the mooring EOM cable. This paper gives the idea of mooring design of buoy, and this paper provide the design criteria of the single point mooring buoy with EOM cable. We compare the dynamics properties and mooring line type under different external environmental load, and the mooring style is optimized. Finally, the dynamic properties and mooring line type during the system deployment process is discussed.}, issn = {2296-7745}, doi = {10.3389/fmars.2022.1048048}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2022.1048048}, author = {Zhang, Shaowei and Tian, Chuan and Zhou, Fenghua} } @article {tzachor_digital_2023, title = {Digital twins: a stepping stone to achieve ocean sustainability?}, journal = {npj Ocean Sustainability}, volume = {2}, number = {1}, year = {2023}, note = {Number: 1 Publisher: Nature Publishing Group}, month = {oct}, pages = {1{\textendash}8}, abstract = {Digital twins, a nascent yet potent computer technology, can substantially advance sustainable ocean management by mitigating overfishing and habitat degradation, modeling, and preventing marine pollution and supporting climate adaptation by safely assessing marine geoengineering alternatives. Concomitantly, digital twins may facilitate multi-party marine spatial planning. However, the potential of this emerging technology for such purposes is underexplored and yet to be realized, with just one notable project entitled European Digital Twins of the Ocean. Here, we consider the promise of digital twins for ocean sustainability across four thematic areas. We further emphasize implementation barriers, namely, data availability and quality, compatibility, and cost. Regarding oceanic data availability, we note the issues of spatial coverage, depth coverage, temporal resolution, and limited data sharing, underpinned, among other factors, by insufficient knowledge of marine processes. Inspired by the prospects of digital twins, and informed by impending difficulties, we propose to improve the availability and quality of data about the oceans, to take measures to ensure data standardization, and to prioritize implementation in areas of high conservation value by following the {\textquoteleft}nested enterprise{\textquoteright} approach.}, keywords = {Engineering, Environmental studies, Ocean sciences, Sustainability}, issn = {2731-426X}, doi = {10.1038/s44183-023-00023-9}, url = {https://www.nature.com/articles/s44183-023-00023-9}, author = {Tzachor, Asaf and Hendel, Ofir and Richards, Catherine E.} } @article {douglass_distributed_2023, title = {Distributed acoustic sensing for detecting near surface hydroacoustic signals}, journal = {JASA Express Letters}, volume = {3}, number = {6}, year = {2023}, month = {jun}, pages = {066005}, abstract = {Distributed acoustic sensing (DAS) is a technology that turns a fiber-optic cable into an acoustic sensor by measuring the phase change of backscattered light caused by changes in strain from an acoustic field. In October 2022, 9 days of DAS and co-located hydrophone data were collected in the Puget Sound near Seattle, WA. Passive data were continuously recorded for the duration and a broadband source was fired from several locations and depths on the first and last days. This dataset provides comparisons between DAS and hydrophone measurements and demonstrates the ability of DAS to measure acoustics signals up to \~{}700 Hz.}, issn = {2691-1191}, doi = {10.1121/10.0019703}, url = {https://doi.org/10.1121/10.0019703}, author = {Douglass, Alexander S. and Abadi, Shima and Lipovsky, Bradley P.} } @article {wilcock_distributed_2023, title = {Distributed acoustic sensing recordings of low-frequency whale calls and ship noise offshore Central Oregon}, journal = {JASA Express Letters}, volume = {3}, number = {2}, year = {2023}, note = {Publisher: Acoustical Society of America}, month = {feb}, pages = {026002}, abstract = {Distributed acoustic sensing (DAS) is a technique that measures strain changes along an optical fiber to distances of \~{}100 km with a spatial sensitivity of tens of meters. In November 2021, 4 days of DAS data were collected on two cables of the Ocean Observatories Initiative Regional Cabled Array extending offshore central Oregon. Numerous 20 Hz fin whale calls, northeast Pacific blue whale A and B calls, and ship noises were recorded, highlighting the potential of DAS for monitoring the ocean. The data are publicly available to support studies to understand the sensitivity of submarine DAS for low-frequency acoustic monitoring.}, doi = {10.1121/10.0017104}, url = {https://asa.scitation.org/doi/full/10.1121/10.0017104}, author = {Wilcock, William S. D. and Abadi, Shima and Lipovsky, Bradley P.} } @article {schiller-weiss_salinity_2023, title = {Do Salinity Variations Along the East Greenland Shelf Show Imprints of Increasing Meltwater Runoff?}, journal = {Journal of Geophysical Research: Oceans}, volume = {128}, number = {10}, year = {2023}, note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2023JC019890}, pages = {e2023JC019890}, abstract = {Accelerated melting of the Greenland Ice Sheet is considered a tipping element in the freshwater balance of the subpolar North Atlantic (SPNA). The East Greenland Current (EGC) and Coastal Current (EGCC) are the major conduits for transporting Arctic-sourced and Greenland glacial freshwater. Understanding freshwater changes in the EGC system and drivers thereof is crucial for connecting tipping elements in the SPNA. Using the eddy-rich model VIKING20X (1/20{\textdegree}) and Copernicus GLORYS12 (1/12{\textdegree}), we find that from 1993 to 2019 freshwater remains close to the shelf with interannual extremes in freshwater content (FWC) attributable to the imprint of Greenland melt only in years 2010 and 2012. Runoff increased significantly from 1995 to 2005 and Arctic freshwater export after 2005. Overall, regional wind patterns, sea ice melt and increasingly glacial ice and snow meltwater runoff along with the Arctic-sourced Polar Water set interannual FWC variations in the EGC system. We emphasize that these freshwater sources have different seasonal timing. South of 65{\textdegree}N sea ice melts year round and retreats to north of 65{\textdegree}N, where melt in summer prevails. Greenland runoff peaks in June{\textendash}August with only some locations of year round discharge. Alongshore winds intensify in fall and winter where reduced onshore Ekman transport allows for freshwater to spread laterally in the EGC. We show that sea ice melt, runoff and wind can cause interannual variations of comparable magnitude. All of which makes attributing ocean freshening events to Greenland meltwater inflow at current magnitudes a major challenge.}, issn = {2169-9291}, doi = {10.1029/2023JC019890}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JC019890}, author = {Schiller-Weiss, Ilana and Martin, Torge and Karstensen, Johannes and Biastoch, Arne} } @article {sasagawa_drift_2023, title = {Drift Corrected Seafloor Pressure Observations of Vertical Deformation at Axial Seamount 2018{\textendash}2021}, journal = {Earth and Space Science}, volume = {10}, number = {2}, year = {2023}, note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022EA002434}, pages = {e2022EA002434}, abstract = {Axial Seamount is a seafloor volcano with frequent eruptions and periodic cycles of inflation and deflation. Seafloor pressure gauges monitor vertical deformation with time, but inherent instrumental drift complicates and biases geodetic interpretation. A drift corrected pressure recorder was deployed on Axial Seamount on 6 July 2018, at coordinates 45{\textdegree} 57.29' North latitude, -130{\textdegree} 0.56' East longitude, depth 1,535 m. This system includes two independent quartz-resonant pressure gauges, which nearly continuously observe the seafloor pressure. At regular intervals, the gauges are calibrated in situ with a modified deadweight tester at a pressure within 98\% of the nominal seafloor pressure. Using the calibration data, the drift of each gauge has been modeled as a simple linear plus decaying exponential function of time. The two estimated linear sensor drift rates are 0.45 {\textpm} 0.12 and 0.36 {\textpm} 0.08 kPa/year; the modeled sensor drift represents a significant error if uncorrected. The standard deviations of the drift model residuals are of order 0.06 kPa or 6 mm depth equivalent. Once calibrated, the difference between the two seafloor pressure timeseries exhibits a RMS deviation of {\textpm}6 mm at the 90\% confidence limit and a linear trend less than 1 mm/year. A time series from July 2018 to December 2021 tracks the inflation of Axial Seamount with differing inflation rates over different time intervals.}, keywords = {instruments and technique, ocean observatories and experiments, standards and absolute measurements, submarine tectonics and volcanism, volcano monitoring}, issn = {2333-5084}, doi = {10.1029/2022EA002434}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022EA002434}, author = {Sasagawa, Glenn S. and Zumberge, Mark A. and Cook, Matthew J.} } @article {bourbonnais_editorial_2023, title = {Editorial: Recent developments in oxygen minimum zones biogeochemistry}, journal = {Frontiers in Marine Science}, volume = {10}, year = {2023}, issn = {2296-7745}, doi = {10.3389/fmars.2023.1333731}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2023.1333731}, author = {Bourbonnais, Annie and Valliyodan, Sudheesh and Altabet, Mark A. and Jayakumar, Amal and Naqvi, Syed Wajih Ahmad and Kumar T. R., Gireesh} } @article {niebergall_evaluation_2023, title = {Evaluation of new and net community production estimates by multiple ship-based and autonomous observations in the Northeast Pacific Ocean}, journal = {Elementa: Science of the Anthropocene}, volume = {11}, number = {1}, year = {2023}, note = {Publisher: University of California Press}, abstract = {New production (NP) and net community production (NCP) measurements are often used as estimates of carbon export potential from the mixed layer of the ocean, an important process in the regulation of global climate. Diverse methods can be used to measure NP and NCP, from research vessels, autonomous platforms, and remote sensing, each with its own set of benefits and uncertainties. The various methods are rarely applied simultaneously in a single location, limiting our ability for direct comparisons of the resulting measurements. In this study, we evaluated NP and NCP from thirteen independent datasets collected via in situ, in vitro, and satellite-based methods near Ocean Station Papa during the 2018 Northeast Pacific field campaign of the NASA project EXport Processes in the Ocean from RemoTe Sensing (EXPORTS). Altogether, the datasets indicate that carbon export potential was relatively low (median daily averages between -5.1 and 12.6 mmol C m-2 d-1), with most measurements indicating slight net autotrophy in the region. This result is consistent with NCP estimates based on satellite measurements of sea surface temperature and chlorophyll a. We explored possible causes of discrepancies among methods, including differences in assumptions about stoichiometry, vertical integration, total volume sampled, and the spatiotemporal extent considered. Results of a generalized additive mixed model indicate that the spatial variation across platforms can explain much of the difference among methods. Once spatial variation and temporal autocorrelation are considered, a variety of methods can provide consistent estimates of NP and NCP, leveraging the strengths of each approach.}, keywords = {14 Life Below Water}, issn = {2785-4558}, doi = {10.1525/elementa.2021.00107}, author = {Niebergall, AK and Traylor, S and Huang, Y and Feen, M and Meyer, MG and McNair, HM and Nicholson, D and Fassbender, AJ and Omand, MM and Marchetti, A and Menden-Deuer, S and Tang, W and Gong, W and Tortell, P and Hamme, R and Cassar, N} } @article {meijers_finale_2023, title = {Finale: impact of the ORCHESTRA/ENCORE programmes on Southern Ocean heat and carbon understanding}, journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences}, volume = {381}, number = {2249}, year = {2023}, note = {Publisher: Royal Society}, month = {may}, pages = {20220070}, abstract = {The 5-year Ocean Regulation of Climate by Heat and Carbon Sequestration and Transports (ORCHESTRA) programme and its 1-year extension ENCORE (ENCORE is the National Capability ORCHESTRA Extension) was an approximately 11-million-pound programme involving seven UK research centres that finished in March 2022. The project sought to radically improve our ability to measure, understand and predict the exchange, storage and export of heat and carbon by the Southern Ocean. It achieved this through a series of milestone observational campaigns in combination with model development and analysis. Twelve cruises in the Weddell Sea and South Atlantic were undertaken, along with mooring, glider and profiler deployments and aircraft missions, all contributing to measurements of internal ocean and air{\textendash}sea heat and carbon fluxes. Numerous forward and adjoint numerical experiments were developed and supported by the analysis of coupled climate models. The programme has resulted in over 100 peer-reviewed publications to date as well as significant impacts on climate assessments and policy and science coordination groups. Here, we summarize the research highlights of the programme and assess the progress achieved by ORCHESTRA/ENCORE and the questions it raises for the future. This article is part of a discussion meeting issue {\textquoteleft}Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities{\textquoteright}.}, keywords = {climate, ocean carbon, ocean circulation, ocean heat, ocean{\textendash}atmosphere fluxes, Southern Ocean}, doi = {10.1098/rsta.2022.0070}, url = {https://royalsocietypublishing.org/doi/full/10.1098/rsta.2022.0070}, author = {Meijers, Andrew J. S. and Meredith, Michael P. and Shuckburgh, Emily F. and Kent, Elizabeth C. and Munday, David R. and Firing, Yvonne L. and King, Brian and Smyth, Tim J. and Leng, Melanie J. and George Nurser, A. J. and Hewitt, Helene T. and Povl Abrahamsen, E. and Weiss, Alexandra and Yang, Mingxi and Bell, Thomas G. and Alexander Brearley, J. and Boland, Emma J. D. and Jones, Daniel C. and Josey, Simon A. and Owen, Robyn P. and Grist, Jeremy P. and Blaker, Adam T. and Biri, Stavroula and Yelland, Margaret J. and Pimm, Ciara and Zhou, Shenjie and Harle, James and Cornes, Richard C.} } @article {chen_finite-time_2023, title = {Finite-time coordination controls for multiple autonomous underwater vehicle systems}, journal = {Engineering Reports}, year = {2023}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1002/eng2.12804}, pages = {e12804}, abstract = {Coordination control of multiple autonomous underwater vehicles (AUVs) has attracted considerable attention owing to its widespread applications in deep-sea exploration, marine environment monitoring, regional searches, and detector recovery. In addition, finite-time control theory is applied to ensure that the system achieves its control goal as soon as possible. To the authors{\textquoteright} knowledge, few studies have systematically summarized the finite-time coordination control of multiple AUV systems. Thus this review aims to systematically and completely introduce the research progress into the coordination control methods for multi-AUV systems and their combination with finite-time theory. The primary areas of focus are the research significance, present state, and prospects of coordination control and finite-time control theory in multiple AUV systems, as well as their applications.}, keywords = {coordination control, finite time convergence, multiple AUV systems}, issn = {2577-8196}, doi = {10.1002/eng2.12804}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1002/eng2.12804}, author = {Chen, Bo and Hu, Jiangping and Ghosh, Bijoy Kumar} } @article {philip_fluid_2023, title = {Fluid sources and overpressures within the central Cascadia Subduction Zone revealed by a warm, high-flux seafloor seep}, journal = {Science Advances}, volume = {9}, number = {4}, year = {2023}, note = {Publisher: American Association for the Advancement of Science}, pages = {eadd6688}, abstract = {Pythia{\textquoteright}s Oasis is a newly discovered seafloor seep on the Central Oregon segment of the Cascadia Subduction Zone, where focused venting emits highly altered fluids ~9{\textdegree}C above the background temperature. The seep fluid chemistry is unique for Cascadia and includes extreme enrichment of boron and lithium and depletion of chloride, potassium, and magnesium. We conclude that the fluids are sourced from pore water compaction and mineral dehydration reactions with minimum source temperatures of 150{\textdegree} to 250{\textdegree}C, placing the source at or near the plate boundary offshore Central Oregon. Estimated fluid flow rates of 10 to 30 cm s-1 are orders of magnitude higher than those estimated elsewhere along the margin and are likely driven by extreme overpressures along the plate boundary. Probable draining of the overpressured reservoir along the vertical Alvin Canyon Fault indicates the important role that such faults may play in the regulation of pore fluid pressure throughout the forearc in Central Cascadia.}, keywords = {3706 Geophysics}, doi = {10.1126/sciadv.add6688}, url = {https://www.science.org/doi/10.1126/sciadv.add6688}, author = {Philip, Brendan T. and Solomon, Evan A. and Kelley, Deborah S. and Tr{\'e}hu, Anne M. and Whorley, Theresa L. and Roland, Emily and Tominaga, Masako and Collier, Robert W.} } @article {beaird_glacial_2023, title = {Glacial Meltwater in the Current System of Southern Greenland}, journal = {Journal of Geophysical Research: Oceans}, volume = {128}, number = {12}, year = {2023}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023JC019658}, pages = {e2023JC019658}, abstract = {The Greenland Ice Sheet is losing mass at an accelerating pace, increasing its contribution to the freshwater input into the Nordic Seas and the subpolar North Atlantic. It has been proposed that this increased freshwater may impact the Atlantic Meridional Overturning Circulation by affecting the stratification of the convective regions of the North Atlantic and Nordic Seas. Observations of the transformation and pathways of meltwater from the Greenland Ice Sheet on the continental shelf and in the gyre interior, however, are lacking. Here, we report on noble gas derived observations of submarine meltwater distribution and transports in the East and West Greenland Current Systems of southern Greenland and around Cape Farewell. In southeast Greenland, submarine meltwater is concentrated in the East Greenland Coastal Current core with maximum concentrations of 0.8\%, thus significantly diluted relative to fjord observations. It is found in water with density ranges from 1,024 to 1027.2 kg m-3 and salinity from 30.6 to 34, which extends as deep as 250 m and as far offshore as 60 km on the Greenland shelf. Submarine meltwater transport on the shelf averages 5.0 {\textpm} 1.6 mSv which, if representative of the mean annual transport, represents 60\%{\textendash}80\% of the total solid ice discharge from East Greenland and suggests relatively little offshore export of meltwater east and upstream of Cape Farewell. The location of the meltwater transport maximum shifts toward the shelfbreak around Cape Farewell, positioning the meltwater for offshore flux in regions of known cross-shelf exchange along the West Greenland coast.}, keywords = {14 Life Below Water, coastal, freshwater, glacier, Greenland, meltwater, tracer}, issn = {2169-9291}, doi = {10.1029/2023JC019658}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JC019658}, author = {Beaird, Nicholas L. and Straneo, Fiamma and Le Bras, Isabela and Pickart, Robert and Jenkins, William J.} } @article {hirzel_high_2023, title = {High resolution analysis of plankton distributions at the middle atlantic bight shelf-break front}, journal = {Continental Shelf Research}, volume = {267}, year = {2023}, pages = {105113}, abstract = {The Middle Atlantic Bight (MAB) is a highly productive ecosystem, supporting several economically important commercial fisheries. Chlorophyll enhancement at the MAB shelf-break front has been observed only intermittently, despite several studies suggesting persistent upwelling at the front. High resolution cross-frontal transects were conducted during three two-week cruises in April 2018, May 2019, and July 2019. Mesoplankton distributions at the front were measured with a Video Plankton Recorder equipped with hydrographic and bio-optical sensors. Zooplankton were also sampled with a Multiple Opening/Closing Net and Environment Sensing System. Each of the three cruises had distinctly different frontal characteristics, with lower variability in frontal position in April 2018 and higher variability in May and July 2019, primarily due to frontal eddies and a Gulf Stream warm core ring, respectively. Eulerian means of all transect crossings within each cruise did not show mean frontal chlorophyll enhancement in April 2018 or July 2019, despite individual crossings showing chlorophyll enhancement in April 2018. Transformation of the April 2018 data into a cross-frontal coordinate system revealed a weak enhancement of chlorophyll and copepods at the front. Mean frontal chlorophyll enhancement was observed in May and was associated with enhancement in the periphery of a frontal eddy rather than the front itself. None of the planktonic categories observed were enhanced at the front in the cross-shelf mean distribution, though diatom chains and copepods were more abundant inshore of the front, particularly in May and July 2019, as well as within the center of a frontal eddy in May. The high variability of the MAB frontal region obscured the impact of ephemeral frontal enhancement in mean observations of April 2018, while frontal eddies contributed to chlorophyll enhancement in mean observations of May 2019. The influence of both argues for the necessity for 3-D models rather than idealized 2-D models to explain frontal behavior and its effects on biological responses.}, keywords = {Chlorophyll, Eddies, Fronts, Plankton, Shelf-break, Video plankton recorder}, issn = {0278-4343}, doi = {10.1016/j.csr.2023.105113}, url = {https://www.sciencedirect.com/science/article/pii/S0278434323001905}, author = {Hirzel, Andrew J. and Alatalo, Philip and Oliver, Hilde and Petitpas, Christian M. and Turner, Jefferson T. and Zhang, Weifeng (Gordon) and McGillicuddy, Dennis J.} } @article {kokkos_hydrography_2023, title = {Hydrography and deep chlorophyll maximum patterns of the Athos Basin and the Thracian Sea continental shelf (North Aegean Sea) combining glider and satellite observations}, journal = {Continental Shelf Research}, volume = {262}, year = {2023}, month = {jun}, pages = {105029}, abstract = {This work focuses on the North Aegean Sea deep chlorophyll maximum (DCM) dynamics, as revealed during the first glider mission over the continental shelf and slope of the Thracian Sea and along the Athos basin, and presents a conceptual model on the response of the DCM in relation to the prevailing stratification/mixing of the water column. Water temperature, conductivity, salinity, chlorophyll-a, CDOM, DO and particle backscatter data (bb700), were recorded during this underwater glider mission in summer 2019. Daily satellite data from Sentinel 3 complemented the glider collected data to validate the satellite-derived estimates of surface Chlorophyll-a levels. The high-resolution physical and chemical observations were analyzed emphasizing on thermal stratification, pycnocline strength, CDOM and dissolved oxygen vertical distribution and the presence of deep chlorophyll maximum (DCM). DCM statistical characteristics were derived by fitting a Gaussian model on the chlorophyll-a profiles. The mean DCM was observed at 76~{\textpm}~14.5~m depth, located below the euphotic layer, estimated at 64~{\textpm}~2.1~m, with the water column dynamics affecting directly its depth, thickness and peak prominence. The satellite-derived chlorophyll-a, integrated within the euphotic layer, was found in fair agreement to the integrated chlorophyll-a values from surface to optical depth recorded by the glider. Chl-a at the DCM were found up to 0.60~mg~m-3, the vertically-integrated pigment content was estimated at 45~{\textpm}~14~mg~m-2 and the values of Optical Community Index (OCI) illustrate the dominance of small-sized plankton. The increased variability in the particulate backscattering coefficient bb700 in Thracian Sea shelf and slope deep waters seems related to sediment resuspension. CDOM levels increased from 0.76~ppb at the sea surface to 1.11~ppb at 40~m depth, being positively correlated to Chl-a within the DCM. CDOM concentration increased steadily at intermediate and deeper waters up to 1.34~{\textpm}~0.07~ppb. DO profiles revealed the presence of an oxycline in the DCM layer, capable to oxygenate the intermediate and deeper waters (+3~{\texttimes}~10-3~ml/L/m). Bottom DO in Athos basin was measured at 5.0~ml~L-1, indicating that the apparent oxygen utilization in Athos Basin is approximately 50~μmol~L-1.}, keywords = {Autonomous underwater vehicle (AUV), Colored dissolved organic matter (CDOM), Deep chlorophyll maximum (DCM), Dissolved oxygen distribution, hydrography, North Aegean Sea}, issn = {0278-4343}, doi = {10.1016/j.csr.2023.105029}, url = {https://www.sciencedirect.com/science/article/pii/S0278434323001061}, author = {Kokkos, Nikolaos and Papadopoulou, Anastasia and Zachopoulos, Konstantinos and Zoidou, Maria and Beguery, Laurent and Margirier, F{\'e}lix and Sylaios, Georgios} } @article {olsen_integrating_2023, title = {Integrating fishers{\textquoteright} knowledge with oceanographic observations to understand changing ocean conditions in the Northeast United States}, journal = {Frontiers in Marine Science}, volume = {10}, year = {2023}, abstract = {Recent warming in the Northeast United States continental shelf ecosystem has raised several concerns about the impacts on the ecosystem and commercial fisheries. In 2014, researchers from the Commercial Fisheries Research Foundation and Woods Hole Oceanographic Institution founded the Shelf Research Fleet to involve fishers in monitoring the rapidly changing ocean environment and encourage sharing of ecological knowledge. The Shelf Research Fleet is a transdisciplinary, cooperative program that trains commercial fishers to collect oceanographic information by deploying conductivity, temperature, and depth (CTD) instruments while commercially fishing. A total of 806 CTD profiles have been collected by the Shelf Research Fleet through December 2022. Participating vessels can view the conductivity and temperature water column profiles they collect in real-time. These profiles help inform their fishing practices and give insights when unexpected species appear in their gear or if their catch composition changes from previous years. The data collected by the Shelf Research Fleet are shared with and processed by researchers from numerous partnering institutions. The Shelf Research Fleet data have been used by researchers to better understand oceanographic phenomena including marine heatwaves, shelf-break exchange processes, warm core rings, and salinity maximum intrusions onto the continental shelf. The scope of the Shelf Research Fleet has grown over time to include efforts to more directly link oceanographic results with biological observations to better understand how changing ocean conditions are affecting commercially important species. This article describes the approach, successes, challenges, and future directions of the Shelf Research Fleet and aims to outline a framework for a cost-effective research program that engages fishers in the collection of oceanographic data, strengthening partnerships between fishing industry members and the scientific community.}, issn = {2296-7745}, doi = {10.3389/fmars.2023.1144178}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2023.1144178}, author = {Olsen, Noelle A. and Bahr, Frank and Bethoney, N. David and Mercer, Anna M. and Gawarkiewicz, Glen} } @article {redick_integration_2023, title = {Integration of untargeted metabolomics and microbial community analyses to characterize distinct deep-sea methane seeps}, journal = {Frontiers in Marine Science}, volume = {10}, year = {2023}, abstract = {Deep-sea methane seeps host highly diverse microbial communities whose biological diversity is distinct from other marine habitats. Coupled with microbial community analysis, untargeted metabolomics of environmental samples using high resolution tandem mass spectrometry provides unprecedented access to the unique specialized metabolisms of these chemosynthetic microorganisms. In addition, the diverse microbial natural products are of broad interest due to their potential applications for human and environmental health and well-being. In this exploratory study, sediment cores were collected from two methane seeps (-1000 m water depth) with very different gross geomorphologies, as well as a non-seep control site. Cores were subjected to parallel metabolomic and microbial community analyses to assess the feasibility of representative metabolite detection and identify congruent patterns between metabolites and microbes. Metabolomes generated using high resolution liquid chromatography tandem mass spectrometry were annotated with predicted structure classifications of the majority of mass features using SIRIUS and CANOPUS. The microbiome was characterized by analysis of 16S rRNA genes and analyzed both at the whole community level, as well as the small subgroup of Actinobacteria, which are known to produce societally useful compounds. Overall, the younger Dagorlad seep possessed a greater abundance of metabolites while there was more variation in abundance, number, and distribution of metabolites between samples at the older Emyn Muil seep. Lipid and lipid-like molecules displayed the greatest variation between sites and accounted for a larger proportion of metabolites found at the older seep. Overall, significant differences in composition of the microbial community mirrored the patterns of metabolite diversity within the samples; both varied greatly as a function of distance from methane seep, indicating a deterministic role of seepage. Interdisciplinary research to understand microbial and metabolic diversity is essential for understanding the processes and role of ubiquitous methane seeps in global systems and here we increase understanding of these systems by visualizing some of the chemical diversity that seeps add to marine systems.}, issn = {2296-7745}, doi = {10.3389/fmars.2023.1197338}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2023.1197338}, author = {Redick, Margaret A. and Cummings, Milo E. and Neuhaus, George F. and Ardor Bellucci, Lila M. and Thurber, Andrew R. and McPhail, Kerry L.} } @article {artana_intense_2023, title = {Intense anticyclones at the global Argentine Basin array of the Ocean Observatory Initiative}, journal = {Ocean Science}, volume = {19}, number = {3}, year = {2023}, note = {Publisher: Copernicus GmbH}, month = {jun}, pages = {953{\textendash}971}, abstract = {We analyzed physical oceanic parameters gathered by a mooring array at mesoscale spatial sampling deployed in the Argentine Basin within the Ocean Observatory Initiative, a National Science Foundation major research facility. The array was maintained at 42o S and 42o W, a historically sparsely sampled region with small ocean variability, over 34 months from March 2015 to January 2018. The data documented four anticyclonic extreme-structure events in 2016. The four anticyclonic structures had different characteristics (size, vertical extension, origin, lifetime and Rossby number). They all featured near-inertial waves (NIWs) trapped at depth and low Richardson values well below the mixed layer. Low Richardson values suggest favorable conditions for mixing. The anticyclonic features likely act as mixing structures at the pycnocline, bringing heat and salt from the South Atlantic Central Water to the Antarctic Intermediate Waters. The intense structures were unique in the 29-year-long satellite altimetry record at the mooring site. The Argentine Basin is populated with many anticyclones, and mixing associated with trapped NIWs probably plays an important role in setting up the upper-water-mass characteristics in the basin.}, issn = {1812-0784}, doi = {10.5194/os-19-953-2023}, url = {https://os.copernicus.org/articles/19/953/2023/}, author = {Artana, Camila and Provost, Christine} } @article {kim_investigation_2023, title = {Investigation of the acoustic properties of underwater rainfall noise measured by a bottom-mounted hydrophone and its application to deep learning to classify and estimate rainfall}, journal = {INTER-NOISE and NOISE-CON Congress and Conference Proceedings}, volume = {268}, number = {2}, year = {2023}, month = {nov}, pages = {6961{\textendash}6964}, abstract = {Although the ocean covers more than 70 \% of the Earth{\textquoteright}s surface, it is difficult to measure precipitation over the ocean due to the technical limitations of platforms such as surface buoys and satellites. Recently, the estimation of precipitation has been tried using the underwater sound generated by rainfall. In this talk, we present the results of comparing underwater noise and rainfall with and without precipitation using the underwater noise and rainfall data provided by OOI (Ocean Observatories Initiative, USA). The acoustic data was acquired by a bottom-moored hydrophone at a depth of 80 m off the coast of Oregon, and the rainfall data was measured from a rain gauge installed on a surface buoy. The 1-minute averaged power spectral densities for ambient noise were computed for 26 days from 5 - 30 April 2018, which were compared with rain rate and wind speed. Based on the comparison results, the presence or absence of rainfall was determined through a pattern recognition neural network, and finally, the amount of precipitation was estimated through multiple linear regression analysis.}, doi = {10.3397/IN_2023_1041}, author = {Kim, DongWook and Lee, Dae Hyeok and Choi, Jee Woong} } @article {le_bras_labrador_2023, title = {Labrador sea water spreading and the Atlantic meridional overturning circulation.}, journal = {Philosophical transactions. Series A, Mathematical, physical, and engineering sciences}, volume = {381}, number = {2262}, year = {2023}, note = {Place: England}, pages = {20220189}, abstract = {In 1982, Talley and McCartney used the low potential vorticity signature of Labrador Sea Water (LSW) to make the first North Atlantic maps of its properties. Forty years later, our understanding of LSW variability, spreading time scales and importance has deepened. In this review and synthesis article, I showcase recent observational advances in our understanding of how LSW spreads from its formation regions into the Deep Western Boundary Current and southward into the subtropical North Atlantic. I reconcile the fact that decadal variability in LSW formation is reflected in the Deep Western Boundary Current with the fact that LSW formation does not control subpolar overturning strength and discuss hypothesized connections between LSW spreading and decadal Atlantic Meridional Overturning Circulation variability. Ultimately, LSW spreading is of fundamental interest because it is a significant pathway for dissolved gasses such as oxygen and carbon dioxide into the deep ocean. We should hence prioritize adding dissolved gas measurements to standard hydrographic and circulation observations, particularly at targeted western boundary locations. This article is part of a discussion meeting issue {\textquoteright}Atlantic overturning: new observations and challenges{\textquoteright}.}, keywords = {deep ocean circulation, high-latitude oceanography, ocean dynamics, water mass analysis}, issn = {1471-2962 1364-503X}, doi = {10.1098/rsta.2022.0189}, author = {Le Bras, Isabela Alexander-Astiz} } @article {morrison_mechanisms_2023, title = {Mechanisms of Heat Flux Across the Southern Greenland Continental Shelf in 1/10{\textdegree} and 1/12{\textdegree} Ocean/Sea Ice Simulations}, journal = {Journal of Geophysical Research: Oceans}, volume = {128}, number = {2}, year = {2023}, note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022JC019021}, pages = {e2022JC019021}, abstract = {The presence of warm Atlantic water on the Greenland continental shelf has been connected to the accelerated melting of the Greenland Ice Sheet, particularly in the southwest and southeast shelf regions. Results from two high-resolution coupled ocean-sea ice simulations that utilized either the 1/10{\textdegree} Parallel Ocean Program (POP) or the 1/12{\textdegree} HYbrid Coordinate Ocean Model (HYCOM) are used to understand the flux of heat on and off the southern Greenland shelf. The analysis reveals that the region of greatest heat flux onto the shelf is southeast Greenland. On the southwestern shelf, heat is mainly exported from the shelf to the interior basins. We identify differences in the shelf break current structure and on-shelf heat content between the two simulations. Just south of the Denmark Strait, there is a seasonally persistent pattern of multi-day variability in the cross-shelf heat flux in both simulations. In the POP simulation, this high-frequency signal results in net on-shore heat flux. In the HYCOM simulation, the signal is weaker and results in net off-shelf heat flux. This variability is consistent with Denmark Strait Overflow eddies traveling along the shelf break.}, keywords = {continental shelf, ice-sheet ocean interactions, ocean modeling}, issn = {2169-9291}, doi = {10.1029/2022JC019021}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022JC019021}, author = {Morrison, Theresa J. and Dukhovskoy, Dmitry S. and McClean, Julie L. and Gille, Sarah T. and Chassignet, Eric P.} } @article {brown_mid-atlantic_2023, title = {Mid-Atlantic Bight cold pool based on ocean glider observations}, journal = {Continental Shelf Research}, volume = {264}, year = {2023}, pages = {105040}, abstract = {During summer, distinctive, bottom-trapped, cold water mass of remnant local and remote winter water called Cold Pool Water (CPW) resides as a swath over the mid to outer continental shelf throughout much of the Mid-Atlantic Bight (MAB). This evolving CPW is important because it strongly influences the ecosystem, including several important fisheries. Thus, there is a priority to better understand the relevant ocean processes and develop CPW forecast capability. Over the past decade, repeated high-resolution Slocum glider measurements of ocean water properties along a New Jersey cross-shelf transect have helped to define the variability of the CPW structure off New Jersey. More recently the Mid-Atlantic Regional Association Coastal Ocean Observing System-supported ocean gliders have occupied a series of along-shelf zigzag trajectories from Massachusetts to New Jersey and New Jersey to Maryland. The comprehensive set of March through November 2007 glider measurements has been used to define the annual evolution of the 10~{\textdegree}C Cold Pool in terms of its distribution and water properties. The rather steady warming at the rate of 1~{\textdegree}C per month July through October 2007 is reflected in the 2007 CPW temperature (T) and salinity (S) properties. We describe how a three-glider fleet view of the September 2013 Cold Pool (a) confirmed the Lentz (2017) CPW cold patch and (b) the impingement of a Gulf Stream warm core ring warmed and salted the 2013 CPW. The Gulf Sream 2013 event forced our extension of the CPW T and S properties.}, keywords = {Cold pool, hydrography, Mid-Atlantic Bight, Ocean glider}, issn = {0278-4343}, doi = {10.1016/j.csr.2023.105040}, url = {https://www.sciencedirect.com/science/article/pii/S0278434323001176}, author = {Brown, W. S. and Schofield, O. and Glenn, S. and Kohut, J. and Boicourt, W.} } @article {evans_mixing_2023, title = {Mixing and air{\textendash}sea buoyancy fluxes set the time-mean overturning circulation in the subpolar North Atlantic and Nordic Seas}, journal = {Ocean Science}, volume = {19}, number = {3}, year = {2023}, note = {Publisher: Copernicus GmbH}, pages = {745{\textendash}768}, abstract = {The overturning streamfunction as measured at the OSNAP (Overturning in the Subpolar North Atlantic Program) mooring array represents the transformation of warm, salty Atlantic Water into cold, fresh North Atlantic Deep Water (NADW). The magnitude of the overturning at the OSNAP array can therefore be linked to the transformation by air{\textendash}sea buoyancy fluxes and mixing in the region north of the OSNAP array. Here, we estimate these water mass transformations using observational-based, reanalysis-based and model-based datasets. Our results highlight that air{\textendash}sea fluxes alone cannot account for the time-mean magnitude of the overturning at OSNAP, and therefore a residual mixing-driven transformation is required to explain the difference. A cooling by air{\textendash}sea heat fluxes and a mixing-driven freshening in the Nordic Seas, Iceland Basin and Irminger Sea precondition the warm, salty Atlantic Water, forming subpolar mode water classes in the subpolar North Atlantic. Mixing in the interior of the Nordic Seas, over the Greenland{\textendash}Scotland Ridge and along the boundaries of the Irminger Sea and Iceland Basin drive a water mass transformation that leads to the convergence of volume in the water mass classes associated with NADW. Air{\textendash}sea buoyancy fluxes and mixing therefore play key and complementary roles in setting the magnitude of the overturning within the subpolar North Atlantic and Nordic Seas. This study highlights that, for ocean and climate models to realistically simulate the overturning circulation in the North Atlantic, the small-scale processes that lead to the mixing-driven formation of NADW must be adequately represented within the model{\textquoteright}s parameterisation scheme.}, keywords = {14 Life Below Water}, issn = {1812-0784}, doi = {10.5194/os-19-745-2023}, url = {https://os.copernicus.org/articles/19/745/2023/}, author = {Evans, Dafydd Gwyn and Holliday, N. Penny and Bacon, Sheldon and Le Bras, Isabela} } @article {schwing_modern_2023, title = {Modern technologies and integrated observing systems are {\textquotedblleft}instrumental{\textquotedblright} to fisheries oceanography: A brief history of ocean data collection}, journal = {Fisheries Oceanography}, volume = {32}, number = {1}, year = {2023}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/fog.12619}, pages = {28{\textendash}69}, abstract = {Interdisciplinary data fuel fisheries oceanography research and the ecosystem-based approaches to management and sustainable development it informs. Underlying this is a distributed ocean observing framework that is integrated, interoperable, interactive, and accessible. In recognition of the 30th anniversary of Fisheries Oceanography the journal, this paper reviews the evolution of observing instruments and platforms used in contemporary fisheries oceanography the science. Illustrated with personal anecdotes, past efforts to create or adopt observing technologies, and examples of their use in research, this highlights the spectrum of instruments, systems, and programs used to survey and monitor ocean ecosystems. Modern ocean observing systems are complex and varied, reflecting the range and diversity of data required by fisheries oceanographers. These systems require a large and ongoing investment and an interdisciplinary community of scientists, engineers, and technicians to design, build, install, operate, and maintain them. Common themes emerge from a review of past successful instrument R\&D and deployments. It is a highly collaborative, integrative, and iterative process. Most systems are the result of vision, planning, and perseverance, backed by careful calibration and intercomparison. Long-term support is essential; public{\textendash}private partnerships that leverage funding, technology, and infrastructure are critical. Sustaining long time series for monitoring population and ecosystem change and to support fisheries oceanography research is a priority. Future areas of focus include continuously innovating and updating technologies, implementing a backbone of core observations, and maintaining a nimble infrastructure and R\&D capacity to seize new opportunities and address emerging challenges.}, keywords = {acoustics, currents, data, fisheries oceanography, observing systems, Satellites, uncrewed systems}, issn = {1365-2419}, doi = {10.1111/fog.12619}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/fog.12619}, author = {Schwing, Franklin B.} } @article {tamsitt_new_2023, title = {New insights into air-sea fluxes and their role in Subantarctic Mode Water formation}, journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences}, volume = {381}, number = {2249}, year = {2023}, note = {Publisher: Royal Society}, month = {may}, pages = {20220066}, abstract = {The formation of Subantarctic Mode Water SAMW in the Southern Ocean plays a key role in the global oceanic uptake and storage of anthropogenic heat and carbon. Wintertime ocean surface heat loss is a dominant driver of Subantarctic Mode Water formation and variability, but wintertime air-sea flux observations in the Southern Ocean are extremely sparse. Recent advances in our understanding of the role of air-sea fluxes in Subantarctic Mode Water Formation from novel ocean observations are summarized here, particularly the role of synoptic atmospheric extreme events, and the drivers of interannual variations in SAMW. These advances in understanding have important implications for variability in Southern Ocean heat and carbon uptake, and can inform future Southern Ocean observing system design. This article is part of a discussion meeting issue {\textquoteleft}Heat and carbon uptake in the Southern Ocean: the state of the art and future priorities{\textquoteright}.}, keywords = {air-sea fluxes, mooring time series, ocean observing, Subantarctic Mode Water, water mass formation}, doi = {10.1098/rsta.2022.0066}, url = {https://royalsocietypublishing.org/doi/full/10.1098/rsta.2022.0066}, author = {Tamsitt, V.} } @article {jones_observation-based_2023, title = {Observation-based estimates of volume, heat, and freshwater exchanges between the subpolar North Atlantic interior, its boundary currents, and the atmosphere}, journal = {Ocean Science}, volume = {19}, number = {1}, year = {2023}, note = {Publisher: Copernicus GmbH}, month = {feb}, pages = {169{\textendash}192}, abstract = {The Atlantic Meridional Overturning Circulation (AMOC) transports heat and salt between the tropical Atlantic and Arctic oceans. The interior of the North Atlantic subpolar gyre (SPG) is responsible for the much of the water mass transformation in the AMOC, and the export of this water to intensified boundary currents is crucial for projecting air{\textendash}sea interaction onto the strength of the AMOC. However, the magnitude and location of exchange between the SPG and the boundary remains unclear. We present a novel climatology of the SPG boundary using quality-controlled CTD (conductivity{\textendash}temperature{\textendash}depth) and Argo hydrography, defining the SPG interior as the oceanic region bounded by 47o N and the 1000 m isobath. From this hydrography we find geostrophic flow out of the SPG around much of the boundary with minimal seasonality. The horizontal density gradient is reversed around western Greenland, where the geostrophic flow is into the SPG. Surface Ekman forcing drives net flow out of the SPG in all seasons with pronounced seasonality, varying between 2.45 {\textpm} 0.73 Sv in the summer and 7.70 {\textpm} 2.90 Sv in the winter. We estimate heat advected into the SPG to be between 0.14 {\textpm} 0.05 PW in the winter and 0.23 {\textpm} 0.05 PW in the spring, and freshwater advected out of the SPG to be between 0.07 {\textpm} 0.02 Sv in the summer and 0.15 {\textpm} 0.02 Sv in the autumn. These estimates approximately balance the surface heat and freshwater fluxes over the SPG domain. Overturning in the SPG varies seasonally, with a minimum of 6.20 {\textpm} 1.40 Sv in the autumn and a maximum of 10.17 {\textpm} 1.91 Sv in the spring, with surface Ekman the most likely mediator of this variability. The density of maximum overturning is at 27.30 kg m-3, with a second, smaller maximum at 27.54 kg m-3. Upper waters (σ0\<27.30 kg m-3) are transformed in the interior then exported as either intermediate water (27.30{\textendash}27.54 kg m-3) in the North Atlantic Current (NAC) or as dense water (σ0\>27.54 kg m-3) exiting to the south. Our results support the present consensus that the formation and pre-conditioning of Subpolar Mode Water in the north-eastern Atlantic is a key determinant of AMOC strength.}, issn = {1812-0784}, doi = {10.5194/os-19-169-2023}, url = {https://os.copernicus.org/articles/19/169/2023/}, author = {Jones, Sam C. and Fraser, Neil J. and Cunningham, Stuart A. and Fox, Alan D. and Inall, Mark E.} } @article {chafik_observed_2023, title = {Observed mechanisms activating the recent subpolar North Atlantic Warming since 2016}, journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences}, volume = {381}, number = {2262}, year = {2023}, note = {Publisher: Royal Society}, month = {oct}, pages = {20220183}, abstract = {The overturning circulation of the subpolar North Atlantic (SPNA) plays a fundamental role in Earth{\textquoteright}s climate variability and change. Here, we show from observations that the recent warming period since about 2016 in the eastern SPNA involves increased western boundary density at the intergyre boundary, likely due to enhanced buoyancy forcing as a response to the strong increase in the North Atlantic Oscillation since the early 2010s. As these deep positive density anomalies spread southward along the western boundary, they enhance the North Atlantic Current and associated meridional heat transport at the intergyre region, leading to increased influx of subtropical heat into the eastern SPNA. Based on the timing of this chain of events, we conclude that this recent warming phase since about 2016 is primarily associated with this observed mechanism of changes in deep western boundary density, an essential element in these interactions. This article is part of a discussion meeting issue {\textquoteleft}Atlantic overturning: new observations and challenges{\textquoteright}.}, keywords = {Atlantic Meridional Overturning Circulation}, doi = {10.1098/rsta.2022.0183}, url = {https://royalsocietypublishing.org/doi/10.1098/rsta.2022.0183}, author = {Chafik, L{\'e}on and Penny Holliday, N. and Bacon, Sheldon and Baker, Jonathan A. and Desbruy{\`e}res, Damien and Frajka-Williams, Eleanor and Jackson, Laura C.} } @article {stevens_ocean_2023, title = {Ocean Ensemble-Enabled Stochastic Acoustic Prediction With Operational Metrics: New England Shelf Break Acoustics Signals and Noise Experiment}, journal = {IEEE Journal of Oceanic Engineering}, year = {2023}, note = {Conference Name: IEEE Journal of Oceanic Engineering}, pages = {1{\textendash}28}, abstract = {This article describes the results of the New England shelf break acoustics (NESBA) experiment as they pertain to acoustic prediction and the quantification of associated uncertainties in relevant operational metrics. The uncertainties considered here are those due to the imperfect sensing of the water column, ambient noise (AN), and the seabed, and the impact this has on ocean forecasting and acoustic performance prediction accuracy. Operational metrics are designed to provide an acoustic system operator with actionable guidance relating to likely mean source detection ranges and associated uncertainties with specific guidance on the degree to which specific environmental factors (e.g., oceanography, seabed, and ambient noise) contribute to the predicted uncertainty levels. High-resolution regional Navy Coastal Ocean Model (NCOM) ensemble forecasts were generated to capture oceanographic variability and uncertainty. Passive ambient noise-based seabed measurements were conducted to estimate seabed properties. Extensive AN and conductivity, temperature, and depth (CTD) measurements were also conducted. Measurement-based versus model-based acoustic prediction metrics are compared as an initial validation of the underlying methodology. It is shown that Global Hybrid Coordinate Ocean Model (HYCOM) ocean forecasts with databased AN and seabed parameters result in very large metric uncertainties, while leveraging high-resolution NCOM with ensembles and in situ AN and seabed measurements can result in substantially reduced uncertainties. It is also demonstrated that improved ocean modeling and sensing can be leveraged to determine the best receiver depth, associated uncertainty levels, and uncertainty drivers. An operational concept for generating acoustic prediction metrics and associated operator environmental sensing guidance is proposed.}, keywords = {acoustics, Cumulative probability of detection, Measurement, passive sonar, Predictive models, Sea measurements, Sea surface, stochastic acoustic prediction, Temperature measurement, uncertainty}, issn = {1558-1691}, doi = {10.1109/JOE.2023.3267788}, author = {Stevens, William K. and Siderius, Martin and Carrier, Matthew J. and Lin, Ying-Tsong and Wendeborn, Drew} } @article {seo_ocean_2023, title = {Ocean Mesoscale and Frontal-Scale Ocean{\textendash}Atmosphere Interactions and Influence on Large-Scale Climate: A Review}, journal = {Journal of Climate}, volume = {36}, number = {7}, year = {2023}, note = {Publisher: American Meteorological Society Section: Journal of Climate}, pages = {1981{\textendash}2013}, abstract = {Two decades of high-resolution satellite observations and climate modeling studies have indicated strong ocean{\textendash}atmosphere coupled feedback mediated by ocean mesoscale processes, including semipermanent and meandrous SST fronts, mesoscale eddies, and filaments. The air{\textendash}sea exchanges in latent heat, sensible heat, momentum, and carbon dioxide associated with this so-called mesoscale air{\textendash}sea interaction are robust near the major western boundary currents, Southern Ocean fronts, and equatorial and coastal upwelling zones, but they are also ubiquitous over the global oceans wherever ocean mesoscale processes are active. Current theories, informed by rapidly advancing observational and modeling capabilities, have established the importance of mesoscale and frontal-scale air{\textendash}sea interaction processes for understanding large-scale ocean circulation, biogeochemistry, and weather and climate variability. However, numerous challenges remain to accurately diagnose, observe, and simulate mesoscale air{\textendash}sea interaction to quantify its impacts on large-scale processes. This article provides a comprehensive review of key aspects pertinent to mesoscale air{\textendash}sea interaction, synthesizes current understanding with remaining gaps and uncertainties, and provides recommendations on theoretical, observational, and modeling strategies for future air{\textendash}sea interaction research. Significance Statement Recent high-resolution satellite observations and climate models have shown a significant impact of coupled ocean{\textendash}atmosphere interactions mediated by small-scale (mesoscale) ocean processes, including ocean eddies and fronts, on Earth{\textquoteright}s climate. Ocean mesoscale-induced spatial temperature and current variability modulate the air{\textendash}sea exchanges in heat, momentum, and mass (e.g., gases such as water vapor and carbon dioxide), altering coupled boundary layer processes. Studies suggest that skillful simulations and predictions of ocean circulation, biogeochemistry, and weather events and climate variability depend on accurate representation of the eddy-mediated air{\textendash}sea interaction. However, numerous challenges remain in accurately diagnosing, observing, and simulating mesoscale air{\textendash}sea interaction to quantify its large-scale impacts. This article synthesizes the latest understanding of mesoscale air{\textendash}sea interaction, identifies remaining gaps and uncertainties, and provides recommendations on strategies for future ocean{\textendash}weather{\textendash}climate research.}, keywords = {14 Life Below Water}, issn = {0894-8755, 1520-0442}, doi = {10.1175/JCLI-D-21-0982.1}, url = {https://journals.ametsoc.org/view/journals/clim/36/7/JCLI-D-21-0982.1.xml}, author = {Seo, Hyodae and O{\textquoteright}Neill, Larry W. and Bourassa, Mark A. and Czaja, Arnaud and Drushka, Kyla and Edson, James B. and Fox-Kemper, Baylor and Frenger, Ivy and Gille, Sarah T. and Kirtman, Benjamin P. and Minobe, Shoshiro and Pendergrass, Angeline G. and Renault, Lionel and Roberts, Malcolm J. and Schneider, Niklas and Small, R. Justin and Stoffelen, Ad and Wang, Qing} } @article {stevens_optimally_2023, title = {Optimally Distributed Receiver Placements Versus an Environmentally Aware Source: New England Shelf Break Acoustics Signals and Noise Experiment}, journal = {IEEE Journal of Oceanic Engineering}, year = {2023}, note = {Conference Name: IEEE Journal of Oceanic Engineering}, abstract = {This article describes the results of the Spring of 2021 New England Shelf Break Acoustics (NESBA) Signals and Noise experiment as they pertain to the optimization of a field of passive receivers versus an environmentally aware source with end-state goals. A discrete optimization has been designed and used to demonstrate providing an acoustic system operator with actionable guidance relating to optimally distributed receiver locations and depths and likely mean source detection times and associated uncertainties as a function of source and receiver levels of environmental awareness. The uncertainties considered here are those due to the imperfect spatial and temporal sensing of the water column, ambient noise (AN), and the seabed, and the impact this has on ocean forecasting and acoustic performance prediction accuracy. As a part of the NESBA experiment, high-resolution (1 km spatial) regional Navy Coastal Ocean Model ensemble forecasts were generated to capture oceanographic variability and uncertainty. Passive AN-based seabed measurements were conducted to estimate seabed properties including variability and uncertainty. Extensive AN and conductivity, temperature, and depth measurements were also conducted. In this article, operationally relevant metrics are employed to estimate the potential value-added of optimal receiver location and depth placements as a function of source end-state goals and assumed level of environmental awareness. A concept for generating stochastic acoustic prediction metrics and associated optimally distributed receiver locations and depths in an operational environment is proposed.}, issn = {1558-1691}, doi = {10.1109/JOE.2023.3302915}, url = {https://ieeexplore.ieee.org/document/10251950}, author = {Stevens, William K. and Siderius, Martin and Carrier, Matthew J. and Wendeborn, Drew} } @article {lozier_overturning_2023, title = {Overturning in the subpolar North Atlantic: a review}, journal = {Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences}, volume = {381}, number = {2262}, year = {2023}, note = {Publisher: Royal Society}, month = {oct}, pages = {20220191}, abstract = {The Overturning in the Subpolar North Atlantic Program (OSNAP) was initiated in the spring of 2010 through a collaborative effort involving the USA, the UK, Germany, the Netherlands and Canada. A key feature of OSNAP is a trans-basin observing system deployed in the summer of 2014 for the continuous measure of volume, heat and freshwater fluxes in the subpolar North Atlantic. This review focuses on advancements made possible by the collective OSNAP observations. Chief among those advancements is the quantification of the dominant role of the eastern subpolar North Atlantic in the production of dense waters that reside in the lower limb of the overturning: the Irminger and Iceland basins contributed approximately three times as much dense water compared with the Labrador Sea over the observational period. Other advancements include elucidation of the relationship between convective activity in the basin interior and boundary current anomalies; the spread of overflow waters in the subpolar region; the seasonality of the meridional volume, heat and freshwater fluxes; and the challenges involved in designing a simpler, less costly observing system. Collectively, OSNAP measurements are laying a framework on which to assess the overturning circulation{\textquoteright}s vulnerability to continued warming and freshening as climate change continues apace. This article is part of a discussion meeting issue {\textquoteleft}Atlantic overturning: new observations and challenges{\textquoteright}.}, keywords = {meridional overturning circulation, OSNAP, subpolar North Atlantic}, doi = {10.1098/rsta.2022.0191}, url = {https://royalsocietypublishing.org/doi/10.1098/rsta.2022.0191}, author = {Lozier, M. Susan} } @article {mccabe_pacific_2023, title = {The Pacific Northwest Harmful Algal Blooms Bulletin}, journal = {Harmful Algae}, volume = {127}, year = {2023}, month = {aug}, pages = {102480}, abstract = {A bulletin communicating risk of toxic Pseudo-nitzschia blooms to shellfish harvest along the open coast of the Pacific Northwest region of the United States (the northeast Pacific Ocean spanning Washington and Oregon) is discussed. This Pacific Northwest Harmful Algal Blooms (PNW HAB) Bulletin is designed for shellfish managers with a focus on the razor clam fishery, but may also be informative to managers of the Dungeness crab fishery since domoic acid accumulation in crabs tends to lag accumulation in razor clams by a couple of weeks. The Bulletin complements beach phytoplankton monitoring programs by alerting coastal shellfish managers about adverse environmental conditions that could be conducive to a toxic Pseudo-nitzschia bloom. Beach monitoring programs are effective at determining when toxins have arrived at shellfish beaches, but a risk forecast based on near real-time biophysical information can provide managers with additional forewarning about potential future toxin outbreaks. Here, the approaches taken in constructing the risk forecasts, along with the reasoning and research behind them are presented. Updates to a historical PNW HAB Bulletin are described, as are the current workflow and the individual components of the updated Bulletin. Some successes and failures realized throughout the process are also pointed out for the benefit of the broader community. A self-assessment suggests that when the necessary data sources are available, the PNW HAB Bulletin provides an accurate forecast of risk associated with toxic Pseudo-nitzschia blooms. The Bulletin has proven beneficial to coastal shellfish managers by better informing decisions on sample collection, and harvest limits, openings, extensions, and closures.}, keywords = {Domoic acid, Harmful algal bloom, Pacific Northwest, PNW HAB Bulletin}, issn = {1568-9883}, doi = {10.1016/j.hal.2023.102480}, url = {https://www.sciencedirect.com/science/article/pii/S1568988323001063}, author = {McCabe, Ryan M. and Hickey, Barbara M. and Trainer, Vera L.} } @mastersthesis {hirzel_physical_2023, title = {Physical and Biological Processes at the Middle Atlantic Bight Shelf-Break Front}, volume = {Doctor of Philosophy}, year = {2023}, note = {Accepted: 2023-04-25T14:21:38Z}, month = {02/2023}, pages = {127}, school = {Massachusetts Institute of Technology}, type = {phdThesis}, address = {Cambridge, MA}, abstract = {The Middle Atlantic Bight (MAB) is a highly productive ecosystem, supporting several economically important commercial fisheries. Chlorophyll enhancement at the MAB shelf-break front has been observed only intermittently, despite numerous studies that suggest persistent upwelling at the front. High resolution cross-frontal transect crossings were collected from three two-week cruises in April 2018, May 2019, and July 2019. Chapter 2 focused on applying a novel method of classifying planktonic images taken by a Video Plankton Recorder to enable processing of the large volumes of data collected with the instrument. Chapter 3 investigated cross-frontal trends by temporally averaging in both Eulerian and frontally-aligned coordinates. For April 2018, transient chlorophyll enhancement was seen at the front in individual transects and within the frontally-aligned mean transect, but not within the Eulerian mean transect. The Eulerian mean for May 2019 showed chlorophyll enhancement as a result of frontal eddies, which were further explored in chapter 4. No frontal enhancement was observed in July 2019. The frontal eddies observed in May 2019 were simulated using an idealized model, which showed that upwelling occurred within both of the frontal eddies, despite having opposite rotational directions. This result was consistent with nutrient enhancement observed within the centers of both eddies. Biological enhancement within each eddy was observed, which may have been a result of advection from source waters and/or a local response to upwelled nutrients. The influence of frontal variability and frontal eddies on nutrients and plankton at the front argues for the necessity for 3-D models to fully explain frontal behavior and its effects on biological responses.}, url = {https://dspace.mit.edu/handle/1721.1/150558}, author = {Hirzel, Andrew Joseph} } @article {lima_predicting_2023, title = {Predicting Carbonate Chemistry on the Northwest Atlantic Shelf using Neural Networks}, journal = {Journal of Geophysical Research Biogeosciences}, volume = {128}, year = {2023}, note = {Publisher: American Geophysical Union (AGU)}, pages = {e2023JG007536}, abstract = {The Northwest Atlantic Shelf (NAS) region has experienced accelerated warming, heatwaves, and is susceptible to ocean acidification, yet also suffers from a paucity of carbonate chemistry observations, particularly at depth. We address this critical data gap by developing three different neural network models to predict dissolved inorganic carbon (DIC) and total alkalinity (TA) in the NAS region from more readily available hydrographic and satellite data. The models predicted DIC with r2 between 0.913{\textendash}0.963 and root mean square errors (RMSE) between 15.4{\textendash}23.7 (μmol kg-1) and TA with r2 between 0.986{\textendash}0.983 and RMSE between 9.0{\textendash}10.4 (μmol kg-1) on an unseen test data set that was not used in training the models. Cross-validation analysis revealed that all models were insensitive to the choice of training data and had good generalization performance on unseen data. Uncertainty in DIC and TA were low (coefficients of variation 0.1\%{\textendash}1\%). Compared with other predictive models of carbonate system variables in this region, a larger and more diverse data set with full seasonal coverage and a more sophisticated model architecture resulted in a robust predictive model with higher accuracy and precision across all seasons. We used one of the models to generate a reconstructed seasonal distribution of carbonate chemistry fields based on DIC and TA predictions that shows a clear seasonal progression and large spatial gradients consistent with observations. The distinct models will allow for a range of applications based on the predictor variables available and will be useful to understand and address ocean sustainability challenges.}, keywords = {13 Climate Action, carbonate chemistry, Machine learning, neural network, Northwest Atlantic, ocean acidification}, issn = {2169-8953}, doi = {10.1029/2023jg007536}, author = {Lima, ID and Wang, ZA and Cameron, LP and Grabowski, JH and Rheuban, JE} } @article {petit_propagation_2023, title = {Propagation and Transformation of Upper North Atlantic Deep Water From the Subpolar Gyre to 26.5{\textdegree}N}, journal = {Journal of Geophysical Research: Oceans}, volume = {128}, number = {8}, year = {2023}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2023JC019726}, pages = {e2023JC019726}, abstract = {Because new observations have revealed that the Labrador Sea is not the primary source for waters in the lower limb of the Atlantic Meridional Overturning Circulation (AMOC) during the Overturning in the Subpolar North Atlantic Programme (OSNAP) period, it seems timely to re-examine the traditional interpretation of pathways and property variability for the AMOC lower limb from the subpolar gyre to 26.5{\textdegree}N. In order to better understand these connections, Lagrangian experiments were conducted within an eddy-rich ocean model to track upper North Atlantic Deep Water (uNADW), defined by density, between the OSNAP line and 26.5{\textdegree}N as well as within the Labrador Sea. The experiments reveal that 77\% of uNADW at 26.5{\textdegree}N is directly advected from the OSNAP West section along the boundary current and interior pathways west of the Mid-Atlantic Ridge. More precisely, the Labrador Sea is a main gateway for uNADW sourced from the Irminger Sea, while particles connecting OSNAP East to 26.5{\textdegree}N are exclusively advected from the Iceland Basin and Rockall Trough along the eastern flank of the Mid-Atlantic Ridge. Although the pathways between OSNAP West and 26.5{\textdegree}N are only associated with a net formation of 1.1 Sv into the uNADW layer, they show large density changes within the layer. Similarly, as the particles transit through the Labrador Sea, they undergo substantial freshening and cooling that contributes to further densification within the uNADW layer.}, issn = {2169-9291}, doi = {10.1029/2023JC019726}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JC019726}, author = {Petit, T. and Lozier, M. S. and R{\"u}hs, S. and Handmann, P. and Biastoch, A.} } @article {danobeitia_role_2023, title = {The role of the marine research infrastructures in the European marine observation landscape: present and future perspectives}, journal = {Frontiers in Marine Science}, volume = {10}, year = {2023}, abstract = {The ocean regulates the exchange, storage of carbon dioxide, plays a key role in global control of Earth climate and life, absorbs most of the heat excess from greenhouse gas emissions and provides a remarkable number of resources for the human being. Most of the geo-hazards occur in oceanic areas. Thus, high-quality systematic observations are necessary tools for improving our understanding, and subsequent assimilation to provide early warning systems. A holistic scientific approach for the understanding of the ocean{\textquoteright}s interrelated processes requires coordinated and complementary monitoring and observation programmes. Research Infrastructures (RIs) are large-scale facilities that provide resources and services for the scientific communities to conduct high-level research and foster innovation. RIs benefit from strong governance and multi-annual funding from their member states with operational life spans in decades. RIs promote knowledge, outreach and education to public, private, and policy stakeholders, and they play a key role in enabling and developing research in all scientific domains and currently represent a growing share of coordinated investment in research, and also in providing essential observations to operational services such as Copernicus. They are strategically important for Europe to lead a global movement towards a data-driven, interconnected, open digital twin that brings together different disciplines, clean technologies, public and private sectors and a broad scientific/technological community, as well as education and training. In Europe several marine RIs have been established, which are maintained by national and European Union (EU) resources. The aims of these infrastructures are aligned with the key priorities of the UN Decade of Ocean Science for Sustainable Development; and with the new European Research Area (ERA) Policy Agenda annexed to the Council conclusions on the ERA governance1, which set out 20 concrete actions for 2022-2024 to contribute to the priority areas defined in the EU Pact for R\&I2. The purpose of this paper is to demonstrate that the combined expertise and assets of Europe{\textquoteright}s marine RIs can form a comprehensive and holistic framework for long-term, sustainable integrated marine observation. Through this integration process the marine RIs can become better and better a significant pillar of the European Ocean Observing System (EOOS). Such a framework must be built as part of interfaces of interaction and promote not only scientific excellence but also innovation at all levels.}, issn = {2296-7745}, doi = {10.3389/fmars.2023.1047251}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2023.1047251}, author = {Da{\~n}obeitia, Juan Jos{\'e} and Pouliquen, Sylvie and Pade, Nicolas and Arvanitidis, Christos and Sanders, Richard and Stanica, Adrian and Gourcuff, Claire and Petihakis, George and Tegas, Valentina and Favali, Paolo} } @inbook {de_rijke_scribble_2023, title = {Scribble on Screens and by Machines}, booktitle = {The Untimely Art of Scribble}, series = {Landscapes: the Arts, Aesthetics, and Education}, year = {2023}, pages = {163{\textendash}194}, publisher = {Springer Nature}, organization = {Springer Nature}, address = {Singapore}, abstract = {This chapter explores examples of both {\textquoteleft}deep{\textquoteright} and {\textquoteleft}shallow{\textquoteright} screen scribbles, without intending a positive or negative value judgement on either. Scribble features on screen from the first robots, television, video and digital experiments, both as {\textquoteleft}deep,{\textquoteright} unanswered experiments questioning human consciousness, sensory perception, meaning or understanding, as well as what could be considered more {\textquoteleft}shallow{\textquoteright} entertaining forays, offering answers into what might be meant by the art of play, creativity or imagination. In this chapter, scribble{\textquoteright}s contribution to a greater understanding of perception are explored via the phenomena of synaesthesia and flux. It marshals evidence against the notion of a disembodied mind for the {\textquoteleft}spatial orientation{\textquoteright} of human experience, such as {\textquoteleft}on{\textendash}off, deep-shallow, central-peripheral{\textquoteright} as meaning that {\textquoteleft}traffics in patterns, images, qualities, feelings and eventually concepts and prepositions{\textquoteright}. Scribble -in flux on screen and by machines- is one of those meaning patterns.}, isbn = {978-981-9921-46-1}, doi = {10.1007/978-981-99-2146-1_7}, url = {https://doi.org/10.1007/978-981-99-2146-1_7}, author = {de Rijke, Victoria} } @article {tooth_seasonal_2023, title = {Seasonal overturning variability in the eastern North Atlantic subpolar gyre: a Lagrangian perspective}, journal = {Ocean Science}, volume = {19}, number = {3}, year = {2023}, note = {Publisher: Copernicus GmbH}, month = {jun}, pages = {769{\textendash}791}, abstract = {Both observations and ocean reanalyses show a pronounced seasonality in the strength of the Atlantic meridional overturning circulation (MOC) within the eastern North Atlantic subpolar gyre (eSPG). However, attributing this overturning seasonality to seasonal dense water formation remains challenging owing to the wide distribution of recirculation timescales within the Iceland and Irminger basins. Here, we investigate the nature of seasonal overturning variability using Lagrangian water parcel trajectories initialised across the Overturning in the Subpolar North Atlantic Program (OSNAP) East section within an eddy-permitting ocean sea ice hindcast. By adopting a Lagrangian perspective, we show that the seasonal minimum of the Eulerian overturning at OSNAP East in autumn results from a combination of enhanced stratification and increased southward transport within the upper East Greenland Current. This convergence of southward transport within the MOC upper limb is explained by decreasing water parcel recirculation times in the upper Irminger Sea, consistent with a gyre-scale response to seasonal wind forcing. To account for the diversity of recirculation times within the eSPG, we also quantify the Lagrangian overturning (LMOC) as the total dense water formation along water parcel trajectories. The majority of water parcels, sourced from the central and southern branches of the North Atlantic Current, fail to return to OSNAP East prior to experiencing wintertime diapycnal transformation into the lower limb, and thus they determine the mean strength of the LMOC within the eSPG (8.9 {\textpm} 2.2 Sv). The strong seasonality of the LMOC is explained by a small collection of upper-limb water parcels, circulating rapidly (<= 8.5 months) in the upper Irminger and central Iceland basins, whose along-stream transformation is determined by their month of arrival at OSNAP East.}, issn = {1812-0784}, doi = {10.5194/os-19-769-2023}, url = {https://os.copernicus.org/articles/19/769/2023/}, author = {Tooth, Oliver John and Johnson, Helen Louise and Wilson, Chris and Evans, Dafydd Gwyn} } @article {fu_seasonality_2023, title = {Seasonality of the Meridional Overturning Circulation in the subpolar North Atlantic.}, journal = {Communications earth \& environment}, volume = {4}, number = {1}, year = {2023}, note = {Place: England}, pages = {181}, abstract = {Understanding the variability of the Atlantic Meridional Overturning Circulation is essential for better predictions of our changing climate. Here we present an updated time series (August 2014 to June 2020) from the Overturning in the Subpolar North Atlantic Program. The 6-year time series allows us to observe the seasonality of the subpolar overturning and meridional heat and freshwater transports. The overturning peaks in late spring and reaches a minimum in early winter, with a peak-to-trough range of 9.0 Sv. The overturning seasonal timing can be explained by winter transformation and the export of dense water, modulated by a seasonally varying Ekman transport. Furthermore, over 55\% of the total meridional freshwater transport variability can be explained by its seasonality, largely owing to overturning dynamics. Our results provide the first observational analysis of seasonality in the subpolar North Atlantic overturning and highlight its important contribution to the total overturning variability observed to date.}, keywords = {Ocean sciences, physical oceanography}, issn = {2662-4435}, doi = {10.1038/s43247-023-00848-9}, author = {Fu, Yao and Lozier, M. Susan and Bil{\'o}, Tiago Carrilho and Bower, Amy S. and Cunningham, Stuart A. and Cyr, Fr{\'e}d{\'e}ric and de Jong, M. Femke and deYoung, Brad and Drysdale, Lewis and Fraser, Neil and Fried, Nora and Furey, Heather H. and Han, Guoqi and Handmann, Patricia and Holliday, N. Penny and Holte, James and Inall, Mark E. and Johns, William E. and Jones, Sam and Karstensen, Johannes and Li, Feili and Pacini, Astrid and Pickart, Robert S. and Rayner, Darren and Straneo, Fiammetta and Yashayaev, Igor} } @article {briciu-burghina_sensors_2023, title = {Sensors for Coastal and Ocean Monitoring}, journal = {Annual Review of Analytical Chemistry}, volume = {16}, number = {1}, year = {2023}, note = {_eprint: https://doi.org/10.1146/annurev-anchem-091922-085746}, pages = {451{\textendash}469}, abstract = {In situ water monitoring sensors are critical to gain an understanding of ocean biochemistry and ecosystem health. They enable the collection of high-frequency data and capture ecosystem spatial and temporal changes, which in turn facilitate long-term global predictions. They are used as decision support tools in emergency situations and for risk mitigation, pollution source tracking, and regulatory monitoring. Advanced sensing platforms exist to support various monitoring needs together with state-of-the-art power and communication capabilities. To be fit-for-purpose, sensors must withstand the challenging marine environment and provide data at an acceptable cost. Significant technological advancements have catalyzed the development of new and improved sensors for coastal and oceanographic applications. Sensors are becoming smaller, smarter, more cost-effective, and increasingly specialized and diversified. This article, therefore, provides a review of the state-of-the art oceanographic and coastal sensors. Progress in sensor development is discussed in terms of performance and the key strategies used for achieving robustness, marine rating, cost reduction, and antifouling protection.}, keywords = {biofouling, coastal monitoring, in situ sensors, Oceanography, review, sensor networks}, doi = {10.1146/annurev-anchem-091922-085746}, url = {https://doi.org/10.1146/annurev-anchem-091922-085746}, author = {Briciu-Burghina, Ciprian and Power, Sean and Delgado, Adrian and Regan, Fiona} } @article {gu_speckle_2023, title = {A speckle noise suppression method based on surface waves investigation and monitoring data}, journal = {Acta Oceanologica Sinica}, volume = {42}, number = {1}, year = {2023}, month = {jan}, pages = {131{\textendash}141}, abstract = {The internal energy distribution of waves can be described using ocean-wave spectra. In many ways, obtaining wave spectra on a global scale is critical. Surface waves investigation and monitoring onboard the Chinese-French oceanography satellite is the first space-borne instrument for detecting wave spectra specially, which was launched on October 29, 2018. It can avoid the shortage of synthetic aperture radar detection results while still having some problems, especially with the effects of speckle noise. In this study, a method to suppress the speckle noise is proposed. First, the empirical formula for background speckle noise is established. Second, many spatio-temporal representative fluctuation spectra are classified and averaged. Third, rational transfer function filtering is used to obtain speckle noise close to the along-track direction. Finally, a signal-to-noise ratio threshold is used to suppress the abnormal speckle noise. This method solves the problems existing in previous denoising methods, such as excessive denoising in the along-track direction and the inability of some abnormal noises to be denoised in the two-dimensional directional wave spectra.}, keywords = {speckle noise, surface waves investigation and monitoring, wave spectra, WaveWatch III}, issn = {1869-1099}, doi = {10.1007/s13131-022-2103-4}, url = {https://doi.org/10.1007/s13131-022-2103-4}, author = {Gu, Jingwei and Li, Xiuzhong and He, Yijun} } @article {risien_stitch_2023, title = {A stitch in time: Combining more than two decades of mooring data from the central Oregon shelf}, journal = {Data in Brief}, volume = {48}, year = {2023}, pages = {109041}, abstract = {The highly biologically productive northern California Current, which includes the Oregon continental shelf, is an archetypal eastern boundary region with summertime upwelling driven by prevailing equatorward winds and wintertime downwelling driven by prevailing poleward winds. Between 1960 and 1990, monitoring programs and process studies conducted off the central Oregon coast advanced the understanding of many oceanographic processes, including coastal trapped waves, seasonal upwelling and downwelling in eastern boundary upwelling systems, and seasonal variability of coastal currents. Starting in 1997, the U.S. Global Ocean Ecosystems Dynamics {\textendash} Long Term Observational Program (GLOBEC-LTOP) continued those monitoring and process study efforts by conducting routine CTD (Conductivity, Temperature, and Depth) and biological sampling survey cruises along the Newport Hydrographic Line (NHL; 44.652{\textdegree}N, 124.1 {\textendash} 124.65{\textdegree}W), located west of Newport, Oregon. Additionally, GLOBEC-LTOP maintained a mooring slightly south of the NHL, nominally at 44.64{\textdegree}N, 124.30{\textdegree}W, on the 81-meter isobath. This location is referred to as NH-10, as it is located 10 nautical miles or 18.5 km west of Newport. A mooring was first deployed at NH-10 in August 1997. This subsurface mooring collected water column velocity data using an upward-looking acoustic Doppler current profiler. A second mooring with a surface expression was deployed at NH-10 starting in April 1999. This mooring included velocity, temperature and conductivity measurements throughout the water column as well as meteorological measurements. GLOBEC-LTOP and the Oregon State University (OSU) National Oceanographic Partnership Program (NOPP) provided funding for the NH-10 moorings from August 1997 to December 2004. Since June 2006, the NH-10 site has been occupied by a series of moorings operated and maintained by OSU with funding from the Oregon Coastal Ocean Observing System (OrCOOS), the Northwest Association of Networked Ocean Observing Systems (NANOOS), the Center for Coastal Margin Observation \& Prediction (CMOP), and most recently the Ocean Observatories Initiative (OOI). While the objectives of these programs differed, each program contributed to long-term observing efforts with moorings routinely measuring meteorological and physical oceanographic variables. This article provides a brief description of each of the six programs, their associated moorings at NH-10, and our efforts to combine over twenty years of temperature, practical salinity, and velocity data into one coherent, hourly averaged, quality-controlled data set. Additionally, the data set includes best-fit seasonal cycles calculated at a daily temporal resolution for each variable using harmonic analysis with a three-harmonic fit to the observations. The stitched together, hourly NH-10 time series and seasonal cycles are available via Zenodo at https://doi.org/10.5281/zenodo.7582475.}, keywords = {California current, Mooring, Newport, NH-10, Oregon, Practical salinity, Seawater temperature, Water velocity}, issn = {2352-3409}, doi = {10.1016/j.dib.2023.109041}, url = {https://www.sciencedirect.com/science/article/pii/S2352340923001592}, author = {Risien, Craig M. and Cervantes, Brandy T. and Fewings, Melanie R. and Barth, John A. and Kosro, P. Michael} } @article {storto_stochastic_2023, title = {Stochastic schemes for the perturbation of the atmospheric boundary conditions in ocean general circulation models}, journal = {Frontiers in Marine Science}, volume = {10}, year = {2023}, abstract = {Advancing the representation of uncertainties in ocean general circulation numerical models is required for several applications, ranging from data assimilation to climate monitoring and extended-range prediction systems. The atmospheric forcing represents one of the main uncertainty sources in numerical ocean models. Here, we formulate and revise different approaches to perturb the air-sea fluxes used within the atmospheric boundary conditions. In particular, perturbation of the fluxes is performed either through i) stochastic modulation of the air-sea transfer coefficients; ii) stochastic modulation of the air-sea flux tendencies; iii) coarse-graining of stochastic sub-grid computation of the fluxes; or iv) multiple bulk formulas. The schemes are implemented and tested in the NEMO4 ocean model, implemented at an eddy-permitting resolution on a domain covering the North Atlantic and Arctic oceans and the Mediterranean Sea. A series of 22-year 4-member ensemble experiments with different stochastic schemes are performed and analyzed for the period 2000-2021, and results are compared in terms of the ensemble mean and, when applicable, ensemble spread of the principal oceanic diagnostics. Results indicate that the schemes, in general, can significantly improve some verification skill scores (e.g. against drifter current speed, SST analyses, and hydrographic profiles) and, in some cases, enhance the mesoscale activity and weaken the large-scale circulation. The response, however, is different depending on the specific scheme, whose choice thus depends on the target application, as detailed in the paper. These findings foster the adoption of these schemes in both extended-range operational ocean forecasts and coupled long-range climate prediction systems, where the boundary conditions perturbations may contribute to performance increases.}, issn = {2296-7745}, doi = {10.3389/fmars.2023.1155803}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2023.1155803}, author = {Storto, Andrea and Yang, Chunxue} } @inbook {lubchenco_technology_2023, title = {Technology, Data and New Models for Sustainably Managing Ocean Resources}, booktitle = {The Blue Compendium: From Knowledge to Action for a Sustainable Ocean Economy}, year = {2023}, pages = {185{\textendash}211}, publisher = {Springer International Publishing}, organization = {Springer International Publishing}, address = {Cham}, abstract = {We are in the middle of an explosion in new data on the ocean, creating enormous potential for advances in our understanding and stewardship of ocean resources. An exponential increase in the number and variety of ocean observing systems and other new data sources has created the prospect of a digital ocean ecosystem. Advances in processing techniques and visualisation are rapidly expanding our ability to extract information from those data, and are enabling a wide array of tools to provide real-time information in actionable form to decision-makers, such as policymakers, resource managers, resource users, consumers and citizens.}, isbn = {978-3-031-16277-0}, doi = {10.1007/978-3-031-16277-0_6}, url = {https://doi.org/10.1007/978-3-031-16277-0_6}, author = {Lubchenco, Jane and Haugan, Peter M.}, editor = {Lubchenco, Jane and Haugan, Peter M.} } @article {shu_technology_2023, title = {Technology Review of Cabled Ocean Observatories}, journal = {Journal of Marine Science and Engineering}, volume = {11}, number = {11}, year = {2023}, note = {Number: 11 Publisher: Multidisciplinary Digital Publishing Institute}, pages = {2074}, abstract = {Cabled ocean observatories (COOs) have enabled real-time in situ ocean observations for decades, thereby facilitating oceanic understanding and exploration. This review discusses typical COOs worldwide in terms of system configurations and state-of-the-art technology, including network structures, power supply modes, and communication capabilities, and provides a comprehensive analysis of their technical routes. The main characteristics of line, ring, star, and grid networks and their applicability in COOs are elucidated, and the advantages and disadvantages of various power supply modes, as well as the opportunities brought by the development of communication technologies, are described. The insights gained from these discussions can inform the implementation of grid structures, optimization of cable routings, expansion of COO scales, application of dual-conductor submarine cables, and upgrading of communication capacity. On this basis, the challenges and future research directions related to COOs are presented.}, keywords = {network structure, ocean observatory, power supply, submarine cable, submarine communication}, issn = {2077-1312}, doi = {10.3390/jmse11112074}, url = {https://www.mdpi.com/2077-1312/11/11/2074}, author = {Shu, Chang and Lyu, Feng and Xu, Rendong and Wang, Xichen and Wei, Wei} } @article {stevens_temperature_2023, title = {Temperature regulates Synechococcus population dynamics seasonally and across the continental shelf}, journal = {Limnology and Oceanography Letters}, year = {2023}, note = {Publisher: Wiley}, abstract = {Hourly, year-round flow cytometry has made it possible to relate seasonal environmental variability to the population dynamics of the smallest, most abundant phytoplankton on the Northeast US Shelf. To evaluate whether the insights from these data extend to Synechococcus farther from shore, we analyze flow cytometry measurements made continuously from the underway systems on 21 cruises traveling between the Martha{\textquoteright}s Vineyard Coastal Observatory (MVCO) and the continental shelf break. We describe how seasonal patterns in Synechococcus, which have been documented in detail at MVCO, occur across the region with subtle variation. We find that the underlying relationship between temperature and division rate is consistent across the shelf and can explain much of the observed spatial variability in concentration. Connecting individual cell properties to annual and regional patterns in environmental conditions, these results demonstrate the value of autonomous monitoring and create an improved picture of picophytoplankton dynamics within an economically important ecosystem.}, keywords = {3708 Oceanography}, issn = {2378-2242}, doi = {10.1002/lol2.10331}, author = {Stevens, Bethany L. F. and Crockford, E. Taylor and Peacock, Emily E. and Neubert, Michael G. and Sosik, Heidi M.} } @article {apprill_toward_2023, title = {Toward a New Era of Coral Reef Monitoring.}, journal = {Environmental science \& technology}, volume = {57}, year = {2023}, note = {Place: United States}, month = {mar}, pages = {5117-5124}, abstract = {Coral reefs host some of the highest concentrations of biodiversity and economic value in the oceans, yet these ecosystems are under threat due to climate change and other human impacts. Reef monitoring is routinely used to help prioritize reefs for conservation and evaluate the success of intervention efforts. Reef status and health are most frequently characterized using diver-based surveys, but the inherent limitations of these methods mean there is a growing need for advanced, standardized, and automated reef techniques that capture the complex nature of the ecosystem. Here we draw on experiences from our own interdisciplinary research programs to describe advances in in situ diver-based and autonomous reef monitoring. We present our vision for integrating interdisciplinary measurements for select "case-study" reefs worldwide and for learning patterns within the biological, physical, and chemical reef components and their interactions. Ultimately, these efforts could support the development of a scalable and standardized suite of sensors that capture and relay key data to assist in categorizing reef health. This framework has the potential to provide stakeholders with the information necessary to assess reef health during an unprecedented time of reef change as well as restoration and intervention activities.}, keywords = {autonomous, coral reef, interdisciplinary, monitoring, sensor, technology}, issn = {1520-5851 0013-936X}, doi = {10.1021/acs.est.2c05369}, author = {Apprill, Amy and Girdhar, Yogesh and Mooney, T. Aran and Hansel, Colleen M. and Long, Matthew H. and Liu, Yaqin and Zhang, W. Gordon and Kapit, Jason and Hughen, Konrad and Coogan, Jeff and Greene, Austin} } @article {petit_understanding_2023, title = {Understanding the Sensitivity of the North Atlantic Subpolar Overturning in Different Resolution Versions of HadGEM3-GC3.1}, journal = {Journal of Geophysical Research: Oceans}, volume = {128}, number = {10}, year = {2023}, note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2023JC019672}, pages = {e2023JC019672}, abstract = {The Atlantic Meridional Overturning Circulation (AMOC) is a key component of the global climate but is not simulated consistently across models or model resolutions. Here, we use a hierarchy of the global coupled model HadGEM3-GC3.1, with ocean resolutions of 1{\textdegree}, {\textonequarter}{\textdegree}, and 1/12{\textdegree}, to evaluate the subpolar AMOC and its sensitivity to horizontal resolution. In line with observations, the models show that the mean overturning and surface forced water mass transformation (SFWMT) are concentrated in the eastern subpolar gyre rather than in the Labrador Sea. However, the magnitude of the overturning along the OSNAP line at medium and high resolutions is 25\% and 40\% larger than in the observations, respectively. This disagreement in overturning strength is noted for both OSNAP East and OSNAP West, and is mainly due to anomalously large SFWMT rather than anomalously large interior mixing or overflow transport from the Nordic Seas. Over the Labrador Sea, the intensification of SFWMT with resolution is explained by a combination of two main biases. Anomalously warm surface water enhances heat loss and reduces the extension of marginal sea ice, which increases the surface density flux over the boundary of the basin. A bias in salinity leads to anomalously dense surface water that shifts the outcropping area of the AMOC isopycnal and results in intense dense water formation along the boundary of the basin at medium and high resolutions. Thus, our analysis sheds light on a range of model biases responsible for large overturning over the Labrador Sea in climate models.}, issn = {2169-9291}, doi = {10.1029/2023JC019672}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2023JC019672}, author = {Petit, T. and Robson, J. and Ferreira, D. and Jackson, L. C.} } @article {ragland_using_2023, title = {Using ocean ambient sound to sense arrival time fluctuations due to temperature}, journal = {The Journal of the Acoustical Society of America}, volume = {154}, number = {4_supplement}, year = {2023}, month = {oct}, pages = {A218}, abstract = {Ambient noise interferometry is a technique that uses coherent ambient sound measured at two separate locations to estimate the Green{\textquoteright}s function between the sensors. Specifically, if the ambient sound is diffuse, the cross-correlation between sensors converges to the Green{\textquoteright}s function between the sensors. In this talk, we apply the technique of ambient noise interferometry to two Ocean Observatories Initiative hydrophones that are separated by 3.2km and bottom mounted at a depth of 1500 m. It has previously been shown that these hydrophones can passively estimate several multi-path propagation peaks reliably throughout the 8 years that they have been recording ambient sound. We present an algorithm that estimates the arrival time of these peaks using the empirical Green{\textquoteright}s function and compare these estimated arrivals to simulated acoustic arrivals. We demonstrate that the arrival times estimated with ambient sound show good agreement with the simulated results and have clear annual fluctuations due to seasonal temperature changes in the water column. We will discuss the future possibilities of extending this work for inversion based oceanographic measurements. [work supported by ONR.]}, issn = {0001-4966}, doi = {10.1121/10.0023334}, url = {https://doi.org/10.1121/10.0023334}, author = {Ragland, John and Abadi, Shima} } @article {cummings_variations_2023, title = {Variations and gradients between methane seep and off-seep microbial communities in a submarine canyon system in the Northeast Pacific}, journal = {PeerJ}, volume = {11}, year = {2023}, note = {Publisher: PeerJ Inc.}, month = {mar}, pages = {e15119}, abstract = {Methane seeps are highly abundant marine habitats that contribute sources of chemosynthetic primary production to marine ecosystems. Seeps also factor into the global budget of methane, a potent greenhouse gas. Because of these factors, methane seeps influence not only local ocean ecology, but also biogeochemical cycles on a greater scale. Methane seeps host specialized microbial communities that vary significantly based on geography, seep gross morphology, biogeochemistry, and a diversity of other ecological factors including cross-domain species interactions. In this study, we collected sediment cores from six seep and non-seep locations from Grays and Quinault Canyons (46{\textendash}47{\textdegree}N) off Washington State, USA, as well as one non-seep site off the coast of Oregon, USA (45{\textdegree}N) to quantify the scale of seep influence on biodiversity within marine habitats. These samples were profiled using 16S rRNA gene sequencing. Predicted gene functions were generated using the program PICRUSt2, and the community composition and predicted functions were compared among samples. The microbial communities at seeps varied by seep morphology and habitat, whereas the microbial communities at non-seep sites varied by water depth. Microbial community composition and predicted gene function clearly transitioned from on-seep to off-seep in samples collected from transects moving away from seeps, with a clear ecotone and high diversity where methane-fueled habitats transition into the non-seep deep sea. Our work demonstrates the microbial and metabolic sphere of influence that extends outwards from methane seep habitats.}, issn = {2167-8359}, doi = {10.7717/peerj.15119}, url = {https://peerj.com/articles/15119}, author = {Cummings, Susie and Bellucci, Lila M. Ardor and Seabrook, Sarah and Raineault, Nicole A. and McPhail, Kerry L. and Thurber, Andrew R.} } @article {toole_vertical_2023, title = {On The Vertical Structure Of Deep Ocean Subinertial Variability}, journal = {Journal of Physical Oceanography}, year = {2023}, note = {Publisher: American Meteorological Society}, keywords = {14 Life Below Water}, issn = {0022-3670}, doi = {10.1175/jpo-d-23-0011.1}, author = {Toole, JM and Musgrave, RC and Fine, EC and Steinberg, JM and Krishfield, RA} } @article {273, title = {Air-Sea Interactions and Water Mass Transformation During a Katabatic Storm in the Irminger Sea}, journal = {Journal of Geophysical Research: Oceans}, volume = {127}, year = {2022}, month = {2022///}, pages = {e2021JC018075}, abstract = {We use a global 5-km resolution model to analyze the air-sea interactions during a katabatic storm in the Irminger Sea originating from the Ammassalik valleys. Katabatic storms have not yet been resolved in global climate models, raising the question of whether and how they modify water masses in the Irminger Sea. Our results show that dense water forms along the boundary current and on the shelf during the katabatic storm due to the heat loss caused by the high wind speeds and the strong temperature contrast. The dense water contributes to the lightest upper North Atlantic Deep Water as upper Irminger Sea Intermediate Water and thus to the lower limb of the Atlantic Meridional Overturning Circulation (AMOC). The katabatic storm triggers a polar low, which in turn amplifies the near-surface wind speed due to the superimposed pressure gradient, in addition to acceleration from a breaking mountain wave. Overall, katabatic storms account for up to 25\% of the total heat loss (20 January 2020 to 30 September 2021) over the Irminger shelf of the Ammassalik area. Resolving katabatic storms in global models is therefore important for the formation of dense water in the western boundary current of the Irminger Sea, which is relevant to the AMOC, and for the large-scale atmospheric circulation by triggering polar lows.}, keywords = {air-sea interaction, DYAMOND Winter, ICON, katabatic winds, storm-resolving global climate model, water mass transformation}, isbn = {2169-9291}, doi = {10.1029/2021JC018075}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JC018075}, author = {Gutjahr, O. and Jungclaus, J. H. and Br{\"u}ggemann, N. and Haak, H. and Marotzke, J.} } @article {swingedouw_amoc_2022, title = {AMOC Recent and Future Trends: A Crucial Role for Oceanic Resolution and Greenland Melting?}, journal = {Frontiers in Climate}, volume = {4}, year = {2022}, abstract = {The Atlantic Meridional Overturning Circulation (AMOC) is a crucial element of the Earth climate. It is a complex circulation system difficult to monitor and to model. There is considerable debate regarding its evolution over the last century as well as large uncertainty about its fate at the end of this century. We depict here the progress since the IPCC SROCC report, offering an update of its chapter 6.7. We also show new results from a high-resolution ocean model and a CMIP6 model to investigate the impact of Greenland Ice Sheet (GrIS) melting, a key uncertainty for past and future AMOC changes. The ocean-only simulation at 1/24{\textdegree} resolution in the Arctic-North Atlantic Ocean performed over the period 2004{\textendash}2016 indicates that the spread of the Greenland freshwater runoff toward the center of the Labrador Sea, where oceanic convection occurs, seems larger in this model than in a CMIP6 model. Potential explanations are related to the model spatial resolution and the representation of mesoscale processes, which more realistically transport the freshwater released around the shelves and, through eddies, provides strong lateral exchanges between the fine-scale boundary current and the convective basin in the Labrador Sea. The larger freshening of the Labrador Sea in the high-resolution model then strongly affects deep convection activity. In the simulation including GrIS melting, the AMOC weakens by about 2 Sv after only 13 years, far more strongly than what is found in the CMIP6 model. This difference raises serious concerns on the ability of CMIP6 models to correctly assess the potential impact of GrIS melting on the AMOC changes over the last few decades as well as on its future fate. To gain confidence in the GrIS freshwater impacts on climate simulations and therefore in AMOC projections, urgent progress should be made on the parameterization of mesoscale processes in ocean models.}, issn = {2624-9553}, doi = {10.3389/fclim.2022.838310}, url = {https://www.frontiersin.org/articles/10.3389/fclim.2022.838310}, author = {Swingedouw, Didier and Houssais, Marie-No{\"e}lle and Herbaut, Christophe and Blaizot, Anne-Cecile and Devilliers, Marion and Deshayes, Julie} } @article {269, title = {Arrival of New Great Salinity Anomaly Weakens Convection in the Irminger Sea}, journal = {Geophysical Research Letters}, volume = {49}, year = {2022}, month = {2022/06/09/}, pages = {e2022GL098857}, abstract = {The Subpolar North Atlantic is prone to recurrent extreme freshening events called Great Salinity Anomalies (GSAs). Here, we combine hydrographic ocean analyses and moored observations to document the arrival, spreading, and impacts of the most recent GSA in the Irminger Sea. This GSA is associated with a rapid freshening of the upper Irminger Sea between 2015 and 2020, culminating in annually averaged salinities as low as the freshest years of the 1990s and possibly since 1960. Upon the GSA propagation into the Irminger Sea over the Reykjanes Ridge, the boundary currents rapidly advected its signal around the basin within months while fresher waters slowly spread and accumulated into the interior. The anomalies in the interior freshened waters produced by deep convection during the 2017{\textendash}2018 winter and actively contributed to the suppression of deep convection in the following two winters.}, keywords = {13 Climate Action}, isbn = {0094-8276}, doi = {10.1029/2022GL098857}, author = {Bil{\'o}, T.C. and Straneo, F. and Holte, J. and Le Bras, I. A.-A.} } @article {282, title = {Automated Tethered Profiler for Hydrophysical and Bio-Optical Measurements in the Black Sea Carbon Observational Site}, journal = {Journal of Marine Science and Engineering}, volume = {10}, year = {2022}, month = {2022/03//}, pages = {322}, abstract = {Biogeochemical cycles of carbon transformation throughout the euphotic zone of the sea are controlled by physical processes, e.g., daily thermocline, variation in solar irradiance, thermohaline convection, and intermittent mixing. These processes should be regularly observed with sufficient time resolution at fixed geographical locations. This study provides a brief overview of the carbon observational site in the Northeastern Black Sea. The focus is on the design of a new tethered profiler Winchi for the inner continental shelf part of the site. The profiler hull and two outriggers comprise an open trimaran platform that is positively buoyant and tends to maintain a horizontal position in the water. The lower end of the winch wire is secured to the bottom anchor. By unwinding/winding the wire, the profiler ascends/descends while measuring the depth profiles of marine environment parameters ranging from the seafloor to air{\textendash}sea interface. After surfacing, the profiler determines its location using the Global Positioning System (GPS) and transmits data to (and from) a server on land through the Global System for Mobile Communications (GSM). Initial field tests with the Winchi profiler at the Northeastern Black Sea shelf exhibited promising results. We report these early tests to demonstrate the use of Winchi.}, keywords = {Black Sea, carbon flux, greenhouse gases, real-time data transmission, tethered profiler, winch}, isbn = {2077-1312}, doi = {10.3390/jmse10030322}, url = {https://www.mdpi.com/2077-1312/10/3/322}, author = {Ostrovskii, Alexander G. and Emelianov, Mikhail V. and Kochetov, Oleg Y. and Kremenetskiy, Vyacheslav V. and Shvoev, Dmitry A. and Volkov, Sergey V. and Zatsepin, Andrey G. and Korovchinsky, Nikolai M. and Olshanskiy, Vladimir M. and Olchev, Alexander V.} } @article {280, title = {Canada{\textquoteright}s Internet-Connected Ocean}, journal = {Frontiers in Marine Science}, volume = {8}, year = {2022}, month = {2022///}, abstract = {Over fifteen years ago, Ocean Networks Canada (ONC) began with the world{\textquoteright}s first large-scale, interactive, real-time portal into the ocean, bringing continuous, real-time data to the surface for applications in scientific research, societal benefits, and supporting Canada{\textquoteright}s ocean industry. This marked the dawn of the Internet-connected ocean, enabling a more fulsome understanding of the ocean through ocean intelligence. These open data have improved our ability to monitor and understand our changing ocean offshore all three coasts of Canada, thanks to diversity of sensor systems to monitor earthquakes and tsunamis, deep sea biodiversity, whales, hydrothermal vents, neutrinos, ocean noise, ocean acidification, forensics experiments, and the impact of climate change, including sea ice thinning in the Arctic. This pioneering approach began in the late 1990s, when scientists began developing a new way of doing ocean science that was no longer limited by weather and ship-time. They imagined a permanent presence in the ocean of sensors to allow a continuous flow of ocean data via the Internet. This big science began to take shape early this century, when a partnership between United States and Canadian institutions was established. ONC evolved out of this international collaboration with seed funding from the Canada Foundation for Innovation, while in the United States, the Ocean Observatories Initiative (OOI) was funded. ONC works closely with OOI on that span the countries{\textquoteright} west coast border. Recently similar observing initiatives in Europe have begun, led by EMSO, which now has a close collaboration with ONC as an Associate Member.}, isbn = {2296-7745}, doi = {10.3389/fmars.2021.805134}, url = {https://www.frontiersin.org/article/10.3389/fmars.2021.805134}, author = {Moran, Kate and Juniper, S. Kim and Bligh, Sandy and Loock, Daniela and Kulin, Ian and Paulson, Meghan and Pirenne, Beno{\^\i}t} } @mastersthesis {ainsworth_carbon_2022, title = {Carbon - trace metal interactions in the oceanic twilight zone}, volume = {Doctor of Philosophy}, year = {2022}, month = {05/2022}, school = {University of Southampton}, type = {PhD}, abstract = {Marine microbes are an important control on carbon (C) sequestration depth and biogeochemical cycling of nutrients and trace metals in the global ocean. The biological carbon pump (BCP) is the set of processes by which inorganic carbon (CO$_\textrm2$) (along with nutrients and trace metals) is fixed into organic matter via photosynthesis by autotrophic phytoplankton and the C, nutrients and trace metals sequestered away from the atmosphere generally by transport into the deep ocean. Most (\textasciitilde80 \%) of the organic C produced by autotrophic phytoplankton is remineralised (returned to the dissolved inorganic inventory from the particulate organic form) in the surface ocean and the inorganic CO$_\textrm2$ is available for release back into the atmosphere. The depth at which remineralisation occurs is important, as the deeper the remineralisation depth of the C the increased likelihood of long term storage in the deep water and sediment. The sequestration of C is primarily dependent on flux attenuation and remineralisation of organic matter in the mesopelagic or {\textquoteleft}twilight{\textquoteright} zone (100-1000 m), where much of the downward particle flux is attenuated via zooplankton and bacterial respiration, replenishing dissolved nutrients and trace metals back into the water column. Understanding the controls on the BCP in the twilight zone is important to understand the transfer efficiency of C sequestration and the regulation of atmospheric CO$_\textrm2$. Oceanic regions such as the Southern Ocean have inefficient BCPs as the phytoplankton are unable to fully utilise available nutrients, restricting their growth and drawdown of C due to limited access to micronutrients such as iron (Fe). Iron is a scare resource in these regions and low concentrations of bioavailable Fe exert significant controls on global phytoplankton productivity, species composition and therefore ecosystem structure and the C cycle. Iron is not only an important micronutrient for phytoplankton growth but also for heterotrophic bacteria, limiting bacterial secondary production and abundance. Two focused and inter-related processes which influence Fe cycling and consequently C cycling in the mesopelagic were investigated. Firstly, differentiating the biotic and abiotic factors on Fe cycling in the twilight zone and the (de-) coupling of Fe and macronutrients at depth. Secondly, to investigate Fe and C (co-) limitation of mesopelagic bacteria. This researched performed shipboard experiments and subsequent laboratory work to evaluate the relative remineralisation rates of C, Fe and silica (Si) from live and detrital phytoplankton cells resuspended in upper mesopelagic waters. Iron consistently transferred from the particulate fraction into the dissolved fraction from both live and detrital cells, this transfer was dominated by the abiotic movement of extracellular adsorbed particulate iron into the dissolved fraction (de- absorption). The live phytoplankton cells remained viable throughout the incubations and continued to respire C whilst the detrital cells potentially leaked dissolved organic C which was subsequently taken up and respired by bacteria with minimal secondary bacterial production. Limited dissolution of Si occurred from the live viable cells with the detrital cells showing more Si dissolution potential. The remineralisation length scales of Fe, C and Si were thus decoupled in the upper mesopelagic as Fe resulted in the shortest remineralisation length scale due the abiotic transfer of extracellular Fe into the dissolved pool, which could resupply biota potentially alleviating Fe limitation. Intracellular pools of Fe (along with C and Si) would be exported to deeper depths with a slow remineralisation rate if processes such as grazing or cell lysis do not act to break cells up and speed up remineralisation processes. Heterotrophic bacterial production was Fe and C (co-) limited in the mesopelagic above the ferricline. An increase in cell abundance of very large high nucleic bacteria when combined Fe and C were added to mesopelagic waters from 150 and 500 m supported a large (1-2 order of magnitude) increase in bacterial production indicating the (co-) limitation of a sub-population of the free-living bacteria at depth. The controls on ferricline depth and mesopelagic standing stocks of Fe (from winter mixing, scavenging, Fe associated with sinking material and the de-absorption of Fe into the water column) will be important in determining the extent of ocean Fe C (co-) limitation of mesopelagic bacterial growth and production and will be a driver in bacterial community composition at depth. Nutrient limitation in the mesopelagic bacteria has potentially important consequences if it also reduces the overall rate of remineralisation and thus both generates a potential reinforcing feedback on the maintenance of a deep ferricline and increases the remineralisation depth and hence long-term storage of carbon in the ocean.}, url = {https://eprints.soton.ac.uk/467733/}, author = {Ainsworth, Joanna Jane} } @article {rudzin_catalyzing_2022, title = {Catalyzing Remote Collaboration During the COVID-19 Pandemic and Beyond: Early Career Oceanographers Adopt Hybrid Open Science Framework}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2022}, month = {jan}, abstract = {The COVID-19 pandemic introduced many challenges for research scientists: reduction of lab and field observation collection and in-person meetings. These new constraints forced researchers to remote work and virtual networking, dramatically influencing scientific inquiry. Such challenges are compounded for those in early stages of their career, where data collection and networking are vital to be seen as productive. However, during this trying time of remote work, we, as a collective of early-career oceanographers, were actively developing and improving on an already-existent hybrid community of practice. Through our experiences, we believe this type of framework can enhance virtual collaboration to the point that it outlasts the pandemic and helps create new synergies that will diversify and enhance scientific inquiry within the ocean science community. We describe a hybrid community of practice and an example workflow that models effective collaboration. We have found that three components to this model are necessary for effective collaboration, inspiration, and communication: 1) openly accessible data, 2) software, computational, and professional-development resources, and 3) a team science approach. In our experience, both the in-person and remote aspects of the model are important. In person collaboration is key to expanding the community of practice and invigorating those already within the community. Remote collaboration has been critical for effective collaborations between in-person activities and has proven to maximize outputs during in-person collaborations. While the three components of this model are not new to the scientific community, we believe that utilizing them strategically post-pandemic will diversify and expand scientific collaboration in oceanography.}, doi = {10.3389/fmars.2022.855192}, url = {https://digitalcommons.odu.edu/oeas_fac_pubs/441}, author = {Rudzin, Johna and Soule, Dax and Whitaker, Justine and Berger, Halle and Clayton, Sophie and Fogaren, Kristen} } @inbook {RN284, title = {Chapter 9 Variability and change}, booktitle = {The Physical Oceanography of the Arctic Mediterranean Sea}, year = {2022}, pages = {433-477}, type = {Book Section}, doi = {10.1016/b978-0-12-816930-8.00006-2}, url = {https://app.dimensions.ai/details/publication/pub.1141547113}, author = {Rudels, Bert} } @article {peters_coastal_2022, title = {Coastal Surface Mooring Developments for the Ocean Observatories Initiative (OOI)}, journal = {Marine Technology Society Journal}, volume = {56}, number = {6}, year = {2022}, month = {dec}, pages = {70{\textendash}74}, abstract = {Abstract Multiple mooring components have been developed at Woods Hole Oceanographic Institution (WHOI) that represent significant advancements in mooring technology. The Ocean Observatories Initiative (OOI) Coastal Surface Moorings are a unique coalescence of these elements into a robust and capable electromechanical mooring design. This paper describes innovative design elements in three key areas that are used operationally on OOI moorings: (1) components at the interface between buoy base and mooring riser, (2) electro-mechanical mooring riser components, and (3) an integrated seafloor anchor and instrument frame. These elements work together as a system that not only provides the necessary mechanical integrity for the mooring, but also provides mounting points for instrumentation and a reliable electrical pathway from the surface to the seafloor.}, keywords = {design elements, OOI, surface mooring}, doi = {10.4031/MTSJ.56.6.2}, author = {Peters, Donald B. and Kemp, John N. and Plueddemann, Albert J.} } @article {saurel_combining_2022, title = {Combining hydro-acoustic sources and bathymetric differences to track the vent evolution of the Mayotte eruption, Mozambique Channel}, journal = {Frontiers in Earth Science}, volume = {10}, year = {2022}, abstract = {The majority of Earth volcanism takes place in the deep ocean. Deep-sea volcanoes are particularly complicated to study due to their remoteness. Very different methods can be used and their combination can lead to crucial information about submarine volcanoes behavior. In Mayotte, Comoros archipelago, efforts have been made to study and monitor the deep volcanic activity (\~{}3000~m) currently occurring east of Mayotte through various methods and campaigns on land and at sea. In October 2020, a line of 10 Ocean Bottom Seismometers was deployed during 10 days, leading to a hand-picked catalog of more than a thousand of hydro-acoustic signals, which have been associated with reactions between hot lava and deep cold ocean waters. During the same period, repeated swath bathymetry surveys were performed over an active lava flow field. We compare the time evolution of the hydro-acoustic events locations and bathymetry differences observed between each survey. While bathymetric information gives absolute location of new lava flows, hydro-acoustic events give detailed relative time variations leading to short-term spatial evolution. Bathymetric information thus provides snapshots of the eruptive area evolution at specific times, when hydro-acoustic signals show its continuous evolution. By combining both complementary analyses we are able to clearly define the detailed evolution of the lava flows pattern in the short time period of 10~days. Applied to the data already acquired on Mayotte since 2019, this method could allow us to estimate more precisely the volcano effusion rate and its evolution, giving further insights on the feeding system.}, issn = {2296-6463}, doi = {10.3389/feart.2022.983051}, url = {https://www.frontiersin.org/articles/10.3389/feart.2022.983051}, author = {Saurel, Jean-Marie and Retailleau, Lise and Deplus, Christine and Loubrieu, Beno{\^\i}t and Pierre, Delphine and Frangieh, Michel and Khelifi, Nassim and Bonnet, Robin and Ferrazzini, Val{\'e}rie and Bazin, Sara and Guyavarch, Pierre and Moulin, Maryline and REVOSIMA Seismology group and REVOSIMA Bathymetry group} } @article {dillon_cost-optimal_2022, title = {Cost-optimal wave-powered persistent oceanographic observation}, journal = {Renewable Energy}, volume = {181}, year = {2022}, pages = {504{\textendash}521}, abstract = {Historically, energy constraints have limited the spatial range, endurance and capabilities of ocean observation systems. Recently developed wave energy conversion technologies have the potential to help overcome these limitations by providing co-located and persistent power generation for ocean observations, enabling new opportunities for ocean research. In this paper, we develop the first techno-economic model for wave-powered ocean observation systems and use the model to study system characteristics and cost drivers. Our model utilizes time-domain simulation and optimization to identify cost-optimal system characteristics and to estimate capital and operational costs. Using our model, we evaluate the use of wave energy to power a 200~W ocean observation system deployed for five years at five unique geographic locations. We found that, depending on the geographic location, cost-optimal wave energy powered systems require an ≈ 0.5{\textendash}3~kW wave energy converter and an ≈ 15-50~kWh battery. The corresponding range of power system costs over the deployment duration is between \$110,800 and \$673,200. We build on these results by performing a sensitivity analysis of key model parameters and identifying the potential economic impact of future technology advancements. Overall, our results indicate that characteristics of the geographic location, power system durability, and electrical power demand are key drivers of power system economics for ocean observing.}, keywords = {blue economy, Ocean observation, Techno-economic analysis, Wave energy}, issn = {0960-1481}, doi = {10.1016/j.renene.2021.08.127}, url = {https://www.sciencedirect.com/science/article/pii/S0960148121012957}, author = {Dillon, Trent and Maurer, Benjamin and Lawson, Michael and Jenne, Dale Scott and Manalang, Dana and Baca, Elena and Polagye, Brian} } @article {wilkin_data-assimilative_2022, title = {A data-assimilative model reanalysis of the U.S. Mid Atlantic Bight and Gulf of Maine: Configuration and comparison to observations and global ocean models}, journal = {Progress in Oceanography}, volume = {209}, year = {2022}, pages = {102919}, abstract = {A 15-year reanalysis (2007{\textendash}2021) of circulation in the coastal ocean and adjacent deep sea of the northeast U.S. continental shelf is described. The analysis uses the Regional Ocean Modeling System (ROMS) and four-dimensional variational (4D-Var) data assimilation (DA) of observations from in situ platforms, coastal radars, and satellites. The reanalysis downscales open boundary information from the Copernicus Marine Environmental Monitoring Service (CMEMS) global analysis. The dynamic model is forced by regional meteorological analyses, observed daily river discharges, and harmonic tides that augment the open boundary conditions. A complementary analysis of the mean seasonal cycle of regional circulation, also computed using ROMS 4D-Var but with climatological mean observations and forcing, is used to reduce biases in the CMEMS boundary data and to provide a dynamically and kinematically constrained Mean Dynamic Topography to use in conjunction with the assimilation of satellite altimeter sea level anomaly observations. The configuration of ROMS 4D-Var used is described, presenting details of the comprehensive suite of observations assembled, data pre-processing and quality control procedures, and background and observation error hypotheses. Control variables of the DA are the initial conditions, surface forcing, and boundary conditions of a sequence of non-overlapping 3-day analysis cycles. Comparisons to a non-assimilative version of the same ROMS model configuration show the added skill brought by assimilation of local observations. The improvement that downscaling with assimilation achieves over ocean state estimates from CMEMS and the U.S. Naval Research Laboratory Global Ocean Forecast System (GOFS) is demonstrated by the reduction in residuals of the DA, and by comparison to independent (unassimilated) observations. Wherever data volumes allow, skill assessments are made with the respect to anomalies from the mean seasonal cycle to emphasize performance at the ocean mesoscale. To highlight the utility of the analysis to inform studies related to coastal sea level variability and marine ecosystems, comparisons are made to unassimilated coastal sea level gauges and novel observations from sensors on fishing gear. The assimilation of coastal satellite altimetry data produces coastal sea level results that are coherent with observations across all time scales from interannual to tidal, while bias and correlation metrics show that bottom temperatures in regions of commercial fishing activity in the Mid-Atlantic Bight and the Gulf of Maine are modeled well.}, keywords = {Bottom temperature, Climatology, Coastal circulation, Data assimilation, Gulf of Maine, Mid Atlantic Bight, Numerical modeling, Sea level}, issn = {0079-6611}, doi = {10.1016/j.pocean.2022.102919}, url = {https://www.sciencedirect.com/science/article/pii/S0079661122001781}, author = {Wilkin, John and Levin, Julia and Moore, Andrew and Arango, Hernan and L{\'o}pez, Alexander and Hunter, Elias} } @article {271, title = {The Deep Ocean Observing Strategy: Addressing Global Challenges in the Deep Sea Through Collaboration}, journal = {Marine Technology Society Journal}, volume = {56}, year = {2022}, month = {2022/06/08/}, pages = {50 - 66}, abstract = {The Deep Ocean Observing Strategy (DOOS) is an international, community-driven initiative that facilitates collaboration across disciplines and fields, elevates a diverse cohort of early career researchers into future leaders, and connects scientific advancements to societal needs. DOOS represents a global network of deep-ocean observing, mapping, and modeling experts, focusing community efforts in the support of strong science, policy, and planning for sustainable oceans. Its initiatives work to propose deep-sea Essential Ocean Variables; assess technology development; develop shared best practices, standards, and cross-calibration procedures; and transfer knowledge to policy makers and deep-ocean stakeholders. Several of these efforts align with the vision of the UN Ocean Decade to generate the science we need to create the deep ocean we want. DOOS works toward (1) a healthy and resilient deep ocean by informing science-based conservation actions, including optimizing data delivery, creating habitat and ecological maps of critical areas, and developing regional demonstration projects; (2) a predicted deep ocean by strengthening collaborations within the modeling community, determining needs for interdisciplinary modeling and observing system assessment in the deep ocean; (3) an accessible deep ocean by enhancing open access to innovative low-cost sensors and open-source plans, making deep-ocean data Findable, Accessible, Interoperable, and Reusable, and focusing on capacity development in developing countries; and finally (4) an inspiring and engaging deep ocean by translating science to stakeholders/end users and informing policy and management decisions, including in international waters.}, keywords = {deep ocean, FAIR data principles, multi-disciplinary, ocean observing, science policy and planning}, isbn = {0025-3324}, doi = {10.4031/MTSJ.56.3.11}, author = {Smith, Leslie M. and Cimoli, Laura and LaScala-Gruenewald, Diana and Pachiadaki, Maria and Phillips, Brennan and Pillar, Helen and Stopa, Justin E. and Baumann-Pickering, Simone and Beaulieu, Stace E. and Bell, Katherine L.C. and Harden-Davies, Harriet and Gjerde, Kristina M. and Heimbach, Patrick and Howe, Bruce and Janssen, Felix and Levin, Lisa A. and Ruhl, Henry A. and Soule, Adam and Stocks, Karen and Vardaro, Michael F. and Wright, Dawn J.} } @article {kashyap_desulfovulcanus_2022, title = {Desulfovulcanus ferrireducens gen. nov., sp. nov., a thermophilic autotrophic iron and sulfate-reducing bacterium from subseafloor basalt that grows on akagan{\'e}ite and lepidocrocite minerals}, journal = {Extremophiles}, volume = {26}, number = {1}, year = {2022}, pages = {13}, abstract = {A deep-sea thermophilic bacterium, strain Ax17T, was isolated from 25~{\textdegree}C hydrothermal fluid at Axial Seamount. It was obligately anaerobic and autotrophic, oxidized molecular hydrogen and formate, and reduced synthetic nanophase Fe(III) (oxyhydr)oxide minerals, sulfate, sulfite, thiosulfate, and elemental sulfur for growth. It produced up to 20~mM Fe2+ when grown on ferrihydrite but < 5~mM Fe2+ when grown on akagan{\'e}ite, lepidocrocite, hematite, and goethite. It was a straight to curved rod that grew at temperatures ranging from 35 to 70~{\textdegree}C (optimum 65~{\textdegree}C) and a minimum doubling time of 7.1~h, in the presence of 1.5{\textendash}6\% NaCl (optimum 3\%) and pH 5{\textendash}9 (optimum 8.0). Phylogenetic analysis based on 16S rRNA gene sequences indicated that the strain was 90{\textendash}92\% identical to other genera of the family Desulfonauticaceae in the phylum Pseudomonadota. The genome of Ax17T was sequenced, which yielded 2,585,834~bp and contained 2407 protein-coding sequences. Based on overall genome relatedness index analyses and its unique phenotypic characteristics, strain Ax17T is suggested to represent a novel genus and species, for which the name Desulfovulcanus ferrireducens is proposed. The type strain is Ax17T (= DSM 111878T = ATCC TSD-233T).}, keywords = {Anaerobic bacteria, Autotroph, Deep sea thermophiles, Hydrothermal vent, Iron reducer, Sulfate reducer}, issn = {1433-4909}, doi = {10.1007/s00792-022-01263-2}, url = {https://doi.org/10.1007/s00792-022-01263-2}, author = {Kashyap, Srishti and Musa, Masroque and Neat, Kaylee A. and Leopo, Deborah A. and Holden, James F.} } @article {lee_detection_2022, title = {Detection of Magma Beneath the Northern and Southern Rift Zones of Axial Seamount at the Juan de Fuca Ridge}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {23}, number = {8}, year = {2022}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022GC010426}, pages = {e2022GC010426}, abstract = {Axial Seamount is an active hotspot-related volcanic system located along the Juan de Fuca Ridge (JdFR) that includes a central volcano and bounding northern and southern rift zones (NRZ and SRZ). Three documented volcanic eruptions in 1998, 2011, and 2015 included dike propagation into and eruptions within the rift zones that are believed to have been sourced from the well-imaged large magma reservoir found beneath the central volcano. However, areas beyond the central volcano have not been explored for potential magma sources that could have contributed to these events, and geochemical studies of older rift zone lavas indicate differences in compositions suggestive of magma reservoirs fed by more mid-ocean ridge-dominated mantle sources. In this study, we analyze multichannel seismic data acquired in 2002 to characterize the internal crustal structure of the rift zones. The new reflectivity images reveal small (<5 km wide) and discontinuous crustal magma bodies at depths of \~{}1.5 to 4 km beneath and in the vicinity of the rift zone lava flows from the three eruptions. We also image wide magma bodies within the overlap regions between the rift zones and neighboring segments of JdFR including a 6.4 km wide body under the east flank of NRZ and a 1-km wide, \~{}400 to 500 m, thick body near the base of the crust under the SRZ-Vance overlap basin. Collectively the new observations indicate that multiple small crustal magma bodies underlie Axial segment, in addition to the main reservoir, and likely contribute to rift zone magmatism with implications for interpretations of seismicity patterns and lava flow compositions.}, issn = {1525-2027}, doi = {10.1029/2022GC010426}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022GC010426}, author = {Lee, Michelle K. and Carbotte, Suzanne M. and Arnulf, Adrien F.} } @article {277, title = {Development of deep neural networks for marine mammal call detection using an open-source, user friendly tool}, journal = {The Journal of the Acoustical Society of America}, volume = {151}, year = {2022}, month = {2022/04//}, pages = {A28}, abstract = {As the collection of large acoustic datasets used to monitor marine mammals increases, so too does the need for expedited and reliable detection of accurately classified bioacoustic signals. Deep learning methods of detection and classification are increasingly proposed as a means of addressing this processing need. These image recognition and classification methods include the use of a neural networks that independently determine important features of bioacoustic signals from spectrograms. Recent marine mammal call detection studies report consistent performance even when used with datasets that were not included in the network training. We present here the use of DeepSqueak, a novel open-source tool originally developed to detect and classify ultrasonic vocalizations from rodents in a low-noise, laboratory setting. We have trained networks in DeepSqueak to detect marine mammal vocalizations in comparatively noisy, natural acoustic environments. DeepSqueak utilizes a regional convolutional neural network architecture within an intuitive graphical user interface that provides automated detection results independent of acoustician expertise. Using passive acoustic data from two hydrophones on the Ocean Observatories Initiative{\textquoteright}s Coastal Endurance Array, we developed networks for humpback whales, delphinids, and fin whales. We report performance and limitations for use of this detection method for each species.}, isbn = {0001-4966}, doi = {10.1121/10.0010547}, url = {https://asa.scitation.org/doi/abs/10.1121/10.0010547}, author = {Ferguson, Elizabeth L. and Sugarman, Peter and Coffey, Kevin R. and Pettis Schallert, Jennifer and Alongi, Gabriela C.} } @article {fruh-green_diversity_2022, title = {Diversity of magmatism, hydrothermal processes and microbial interactions at mid-ocean ridges}, journal = {Nature Reviews Earth \& Environment}, year = {2022}, note = {Publisher: Nature Publishing Group}, month = {nov}, pages = {1{\textendash}20}, abstract = {Hydrothermal circulation and alteration at mid-ocean ridges and ridge flanks have a key role in regulating seawater chemistry and global chemical fluxes, and support diverse ecosystems in the absence of light. In this Review, we outline tectonic, magmatic and hydrothermal processes that govern crustal architecture, alteration and biogeochemical cycles along mid-ocean ridges with different spreading rates. In general, hydrothermal systems vary from those that are magmatic-dominated with low-pH fluids >300 {\textdegree}C to serpentinizing systems with alkaline fluids <120 {\textdegree}C. Typically, slow-spreading ridges (rates <40 mm yr-1) have greater variability in magmatism, lithology and vent chemistry, which are influenced by detachment faults that expose lower-crustal and serpentinized mantle rocks. Hydrothermal alteration is an important sink for magnesium, sodium, sulfate and bicarbonate, and a net source of volatiles, iron and other nutrients to the deep ocean and vent ecosystems. Magmatic hydrothermal systems sustain a vast, hot and diverse microbial biosphere that represents a deep organic carbon source to ocean carbon budgets. In contrast, high-pH serpentinizing hydrothermal systems harbour a more limited microbial community consisting primarily of methane-metabolizing archaea. Continued advances in monitoring and analytical capabilities coupled with developments in metagenomic technologies will guide future investigations and discoveries in hydrothermal systems.}, keywords = {Element cycles, Geochemistry, Marine biology, Tectonics}, issn = {2662-138X}, doi = {10.1038/s43017-022-00364-y}, url = {https://www.nature.com/articles/s43017-022-00364-y}, author = {Fr{\"u}h-Green, Gretchen L. and Kelley, Deborah S. and Lilley, Marvin D. and Cannat, Mathilde and Chavagnac, Valerie and Baross, John A.} } @article {oliver_ephemeral_2022, title = {Ephemeral Surface Chlorophyll Enhancement at the New England Shelf Break Driven by Ekman Restratification}, journal = {JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS}, volume = {127}, number = {1}, year = {2022}, month = {jan}, pages = {e2021JC017715}, abstract = {The Mid-Atlantic Bight (MAB) hosts a large and productive marine ecosystem supported by high phytoplankton concentrations. Enhanced surface chlorophyll concentrations at the MAB shelf-break front have been detected in synoptic measurements, yet this feature is not present in seasonal means. To understand why, we assess the conditions associated with enhanced surface chlorophyll at the shelf break. We employ in-situ and remote sensing data, and a 2-dimensional model to show that Ekman restratification driven by upfront winds drives ephemerally enhanced chlorophyll concentrations at the shelf-break front in spring. Using 8-day composite satellite-measured surface chlorophyll concentration data from 2003{\textendash}2020, we constructed a daily running mean (DRM) climatology of the cross-shelf chlorophyll distribution for the northern MAB region. While the frontal enhancement of chlorophyll is apparent in the DRM climatology, it is not captured in the seasonal climatology due to its short duration of less than a week. In-situ measurements of the frontal chlorophyll enhancement reveal that chlorophyll is highest in spring when the shelf-break front slumps offshore from its steep wintertime position causing restratification in the upper part of the water column. Several restratification mechanisms are possible, but the first day of enhanced chlorophyll at the shelf break corresponds to increasing upfront winds, suggesting that the frontal restratification is driven by offshore Ekman transport of the shelf water over the denser slope water. The 2-dimensional model shows that upfront winds can indeed drive Ekman restratification and alleviate light limitation of phytoplankton growth at the shelf-break front.}, issn = {2169-9275}, doi = {10.1029/2021JC017715}, author = {Oliver, Hilde and Zhang, Weifeng Gordon and Archibald, Kevin M. and Hirzel, Andrew J. and Smith, Walker O. and Sosik, Heidi M. and Stanley, Rachel H. R. and McGillicuddy, Jr., Dennis J.} } @article {silveira_ever-changing_2022, title = {The Ever-Changing and Challenging Role of Ocean Observation: From Local Initiatives to an Oceanwide Collaborative Effort}, journal = {Frontiers in Marine Science}, volume = {8}, year = {2022}, abstract = {Ocean observation has seen a rapid evolution and has become crucial in providing the much needed data and information toward a well-supported and accurate description of ocean processes which influence the environmental, economic, and societal systems. There has been a significant progress in technologies which have enabled the expansion of the sampling and observing systems both on temporal and spatial scales. Furthermore, online, free access, data portals have grown in number and quality, provided by data aggregators, which have promoted the creation of standardized methods for marine data acquisition and management. Ocean observation is now global, but it depends on the single institutions and laboratories{\textquoteright} capability to guarantee the operation of instruments and longevity in data acquisition. International collaborative initiatives are crucial to support the ever-growing databases and feed the services and products that are fundamental to Blue Growth. Collaboration must be developed at local and regional levels and the monitoring system must ensure data consistency, integrity, and redundancy. The {\textquotedblleft}Atlantic Observatory {\textendash} Data and Monitoring Infrastructure{\textquotedblright} project, is an example of a Portuguese effort to bring together on-going initiatives working in the Atlantic area and provide access to high quality marine environmental data covering the Atlantic Ocean basin.}, issn = {2296-7745}, doi = {10.3389/fmars.2021.778452}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2021.778452}, author = {Silveira, Tanya Mendes and Carapu{\c c}o, Mafalda Marques and Miranda, Jorge Miguel} } @article {ragland_exploring_2022, title = {Exploring surface source contributions to ocean ambient noise interferometry with airgun shots}, journal = {The Journal of the Acoustical Society of America}, volume = {152}, number = {5}, year = {2022}, note = {Publisher: Acoustical Society of America}, month = {nov}, pages = {3069{\textendash}3077}, abstract = {A seismic reflection survey conducted directly over two bottom-mounted hydrophones in the north-east Pacific Ocean is used to explore how surface source locations affect ambient noise interferometry for the two hydrophones. The airgun shots are used as an approximation of an impulsive sound source at a discrete location, which allows us to investigate spatial contributions to the cross correlation between the two hydrophones. Simulated and experimental results are presented. The contributions to the cross correlations are explained by different reflections off the surface or bottom of the ocean, and a discussion about what can and cannot be inferred about the emergence to the Green{\textquoteright}s function is presented.}, issn = {0001-4966}, doi = {10.1121/10.0015231}, url = {https://asa.scitation.org/doi/10.1121/10.0015231}, author = {Ragland, John and Abadi, Shima} } @article {kostov_fast_2022, title = {Fast mechanisms linking the Labrador Sea with subtropical Atlantic overturning}, journal = {Climate Dynamics}, year = {2022}, month = {aug}, abstract = {We use an ocean general circulation model and its adjoint to analyze the causal chain linking sea surface buoyancy anomalies in the Labrador Sea to variability in the deep branch of the Atlantic meridional overturning circulation (AMOC) on inter-annual timescales. Our study highlights the importance of the North Atlantic Current (NAC) for the north-to-south connectivity in the AMOC and for the meridional transport of Lower North Atlantic Deep Water (LNADW). We identify two mechanisms that allow the Labrador Sea to impact velocities in the LNADW layer. The first mechanism involves a passive advection of surface buoyancy anomalies from the Labrador Sea towards the eastern subpolar gyre by the background NAC. The second mechanism plays a dominant role and involves a dynamical response of the NAC to surface density anomalies originating in the Labrador Sea; the NAC adjustment modifies the northward transport of salt and heat and exerts a strong positive feedback, amplifying the upper ocean buoyancy anomalies. The two mechanisms spin up/down the subpolar gyre on a timescale of years, while boundary trapped waves rapidly communicate this signal to the subtropics and trigger an adjustment of LNADW transport on a timescale of months. The NAC and the eastern subpolar gyre play an essential role in both mechanisms linking the Labrador Sea with LNADW transport variability and the subtropical AMOC. We thus reconcile two apparently contradictory paradigms about AMOC connectivity: (1) Labrador Sea buoyancy anomalies drive AMOC variability; (2) water mass transformation is largest in the eastern subpolar gyre.}, keywords = {AMOC, Atlantic Meridional Overturning Circulation, Labrador Sea, LNADW, Lower North Atlantic Deep Water, NAC, North Atlantic Current, OSNAP, RAPID-MOCHA, Surface heat fluxes, water mass transformation}, issn = {1432-0894}, doi = {10.1007/s00382-022-06459-y}, url = {https://doi.org/10.1007/s00382-022-06459-y}, author = {Kostov, Yavor and Messias, Marie-Jos{\'e} and Mercier, Herl{\'e} and Johnson, Helen L. and Marshall, David P.} } @article {butte_framework_2022, title = {A Framework for Water Security Data Gathering Strategies}, journal = {Water}, volume = {14}, number = {18}, year = {2022}, note = {Number: 18 Publisher: Multidisciplinary Digital Publishing Institute}, month = {jan}, pages = {2907}, abstract = {At the international level, the term {\textquotedblleft}water security{\textquotedblright} (WS) has gained increasing attention in recent decades. At the operational level, WS is assessed using tools that define the concept using a variety of dimensions and sub-dimensions, with qualitative and quantitative indicators and parameters. The breadth of tools and concepts is an obstacle to the operationalisation of the concept of water security (WS). Clearly, we need a range of diverse data to evaluate water security (WS). However, there are several barriers to designing an optimal Data Gathering Strategy (DGS). Such a strategy must strike a balance between a wide range of competing and overlapping data requirements and characteristics including: resources, information, and impact. The proposed framework aims at filling the existing gaps, not by providing a strict procedure, but instead acting as a {\textquotedblleft}compass{\textquotedblright}: five interfaces between data and context are identified to orient practitioners towards an optimal DGS. The conceptual aim of the framework can be summarised as shifting the focus of the DGS from a {\textquotedblleft}data-to-information approach{\textquotedblright} to a {\textquotedblleft}data-to-action approach,{\textquotedblright} therefore stressing the importance of reaching key stakeholders with information. The specific aims of this paper are to: identify the key issues that should be addressed in designing a Data Gathering Strategy for Water Security (DGSxWS); communicate the key issues with a clear conceptual framework; and suggest approaches and activities that could help water practitioners in dealing with the issues identified.}, keywords = {data gathering, interdisciplinarity, minimum dataset, systemic, water security}, issn = {2073-4441}, doi = {10.3390/w14182907}, url = {https://www.mdpi.com/2073-4441/14/18/2907}, author = {Butte, Giacomo and Solano-Correa, Yady Tatiana and Peppa, Maria Valasia and Ru{\'\i}z-Ord{\'o}{\~n}ez, Diana Marcela and Maysels, Rachael and Tuqan, Nasser and Polaine, Xanthe and Montoya-Pachongo, Carolina and Walsh, Claire and Curtis, Thomas} } @article {chadwick_geodetic_2022, title = {Geodetic Monitoring at Axial Seamount Since Its 2015 Eruption Reveals a Waning Magma Supply and Tightly Linked Rates of Deformation and Seismicity}, journal = {Geochemistry Geophysics Geosystems}, volume = {23}, number = {1}, year = {2022}, note = {Place: Washington Publisher: Amer Geophysical Union WOS:000751308100015}, pages = {e2021GC010153}, abstract = {Axial Seamount is a basaltic hot spot volcano with a summit caldera at a depth of similar to 1,500 m below sea level, superimposed on the Juan de Fuca spreading ridge, giving it a robust and continuous magma supply. Axial erupted in 1998, 2011, and 2015, and is monitored by a cabled network of instruments including bottom pressure recorders and seismometers. Since its last eruption, Axial has re-inflated to 85\%-90\% of its pre-eruption level. During that time, we have identified eight discrete, short-term deflation events of 1-4 cm over 1-3 weeks that occurred quasi-periodically, about every 4-6 months between August 2016 and May 2019. During each short-term deflation event, the rate of earthquakes dropped abruptly to low levels, and then did not return to higher levels until reinflation had resumed and returned near its previous high. The long-term geodetic monitoring record suggests that the rate of magma supply has varied by an order of magnitude over decadal time scales. There was a surge in magma supply between 2011 and 2015, causing those two eruptions to be closely spaced in time and the supply rate has been waning since then. This waning supply has implications for eruption forecasting and the next eruption at Axial still appears to be 4-9 years away. We also show that the number of earthquakes per unit of uplift has increased exponentially with total uplift since the 2015 eruption, a pattern consistent with a mechanical model of cumulative rock damage leading to bulk failure during magma accumulation between eruptions.}, keywords = {bottom pressure recorders, de-fuca ridge, eruption forecasting, galapagos, ground deformation, high-resolution, inflation, kilauea volcano, lava flows, midocean ridge, ocean bottom seismometers, OOI cabled observatory, precursors, seafloor geodesy, sierra-negra-volcano, submarine volcano monitoring}, doi = {10.1029/2021GC010153}, url = {https://www.webofscience.com/api/gateway?GWVersion=2\&SrcAuth=DOISource\&SrcApp=WOS\&KeyAID=10.1029\%2F2021gc010153\&DestApp=DOI\&SrcAppSID=USW2EC0AF0FhQ3gq3aJ9tUIgn6Kiy\&SrcJTitle=GEOCHEMISTRY+GEOPHYSICS+GEOSYSTEMS\&DestDOIRegistrantName=American+Geophysical+Uni}, author = {Chadwick, William W. and Wilcock, William S. D. and Nooner, Scott L. and Beeson, Jeffrey W. and Sawyer, Audra M. and Lau, T.-k} } @article {johnson_global_2022, title = {Global Oceans}, journal = {Bulletin of the American Meteorological Society}, volume = {103}, number = {8}, year = {2022}, month = {aug}, pages = {s143{\textendash}s192}, issn = {0003-0007}, doi = {10.1175/bams-d-22-0072.1}, author = {Johnson, GC and Lumpkin, R and Boyer, T and Bringas, F and Cetini{\'c}, I and Chambers, DP and Cheng, L and Dong, S and Feely, RA and Fox-Kemper, B and Frajka-Williams, E and Franz, BA and Fu, Y and Gao, M and Garg, J and Gilson, J and Goni, G and Hamlington, BD and Hewitt, HT and Hobbs, WR and Hu, Z-Z and Huang, B and Jevrejeva, S and Johns, WE and Katsunari, S and Kennedy, JJ and Kersal{\'e}, M and Killick, RE and Leuliette, E and Locarnini, R and Lozier, MS and Lyman, JM and Merrifield, MA and Mishonov, A and Mitchum, GT and Moat, BI and Nerem, RS and Notz, D and Perez, RC and Purkey, SG and Rayner, D and Reagan, J and Schmid, C and Siegel, DA and Smeed, DA and Stackhouse, PW and Sweet, W and Thompson, PR and Volkov, DL and Wanninkhof, R and Weller, RA and Wen, C and Westberry, TK and Widlansky, MJ and Willis, JK and Yu, L and Zhang, H-M} } @article {270, title = {Historical Reconstruction of Subpolar North Atlantic Overturning and Its Relationship to Density}, journal = {Journal of Geophysical Research: Oceans}, volume = {127}, year = {2022}, month = {2022/06//}, pages = {e2021JC017732}, abstract = {The connections between the overturning of the subpolar North Atlantic and regional density changes are assessed on interannual and decadal timescales using historical, data-based reconstructions of the overturning over the last 60 years and forward model integrations with buoyancy and wind forcing. The data-based reconstructions reveal a dominant eastern basin contribution to the subpolar overturning in density space and changes in the overturning reaching {\textpm}2.5 Sv, which are both in accord with the Overturning in the Subpolar North Atlantic Program (OSNAP). The zonally integrated geostrophic velocity across the basin is connected to boundary contrasts in Montgomery potential in density space. The overturning for the eastern side of the basin is strongly correlated with density changes in the Irminger and Labrador Seas, while the overturning for the western side is correlated with boundary density changes in the Labrador Sea. These boundary density signals are a consequence of local atmospheric forcing and transport of upstream density changes. In forward model experiments, a localized density increase over the Irminger Sea increases the overturning over both sides of the basin due to dense waters spreading to the Labrador Sea. Conversely, a localized density increase over the Labrador Sea only increases the overturning for the western basin and instead eventually decreases the overturning for the eastern basin. Labrador Sea density provides a useful overturning metric by its direct control of the overturning over the western side and lower latitudes of the subpolar basin.}, isbn = {2169-9275}, doi = {10.1029/2021JC017732}, author = {Roussenov, Vassil M. and Williams, Richard G. and Lozier, M. Susan and Holliday, N. Penny and Smith, Doug M.} } @article {267, title = {How Is the Ocean Anthropogenic Carbon Reservoir Filled?}, journal = {GLOBAL BIOGEOCHEMICAL CYCLES}, volume = {36}, year = {2022}, month = {2022/05//}, pages = {e2021GB007055}, abstract = {About a quarter of the total anthropogenic CO2 emissions during the industrial era has been absorbed by the ocean. The rate limiting step for this uptake is the transport of the anthropogenic carbon (Cant) from the ocean mixed layer where it is absorbed to the interior ocean where it is stored. While it is generally known that deep water formation sites are important for vertical carbon transport, the exact magnitude of the fluxes across the base of the mixed layer in different regions is uncertain. Here, we determine where, when, and how much Cant has been injected across the mixed-layer base and into the interior ocean since the start of the industrialized era. We do this by combining a transport matrix derived from observations with a time-evolving boundary condition obtained from already published estimates of ocean Cant. Our results show that most of the Cant stored below the mixed layer are injected in the subtropics (40.1\%) and the Southern Ocean (36.0\%), while the Subpolar North Atlantic has the largest fluxes. The Subpolar North Atlantic is also the most important region for injecting Cant into the deep ocean with 81.6\% of the Cant reaching depths greater than 1,000 m. The subtropics, on the other hand, have been the most efficient in transporting Cant across the mixed-layer base per volume of water ventilated. This study shows how the oceanic Cant uptake relies on vertical transports in a few oceanic regions and sheds light on the pathways that fill the ocean Cant reservoir.}, keywords = {anthropogenic carbon, fluxes, mixed-layer, observations, transport matrix}, isbn = {0886-6236}, doi = {10.1029/2021GB007055}, author = {Davila, Xabier and Gebbie, Geoffrey and Brakstad, Ailin and Lauvset, Siv K. and McDonagh, Elaine L. and Schwinger, Jorg and Olsen, Are} } @inbook {RN275, title = {Hydrate Ridge{\textemdash}A Gas Hydrate System in a Subduction Zone Setting}, booktitle = {World Atlas of Submarine Gas Hydrates in Continental Margins}, year = {2022}, pages = {89-107}, type = {Book Section}, doi = {10.1007/978-3-030-81186-0_7}, url = {https://app.dimensions.ai/details/publication/pub.1144317993}, author = {Bangs, Nathan L. and Johnson, Joel E. and Tr{\'e}hu, Anne M. and Arsenault, Matthew A.} } @article {cerovecki_impact_2022, title = {Impact of downward longwave radiative deficits on Antarctic sea-ice extent predictability during the sea ice growth period}, journal = {Environmental Research Letters}, volume = {17}, number = {8}, year = {2022}, note = {Place: Bristol Publisher: IOP Publishing Ltd WOS:000827243700001}, pages = {084008}, abstract = {Forecasting Antarctic atmospheric, oceanic, and sea ice conditions on subseasonal to seasonal scales remains a major challenge. During both the freezing and melting seasons current operational ensemble forecasting systems show a systematic overestimation of the Antarctic sea-ice edge location. The skill of sea ice cover prediction is closely related to the accuracy of cloud representation in models, as the two are strongly coupled by cloud radiative forcing. In particular, surface downward longwave radiation (DLW) deficits appear to be a common shortcoming in atmospheric models over the Southern Ocean. For example, a recent comparison of ECMWF reanalysis 5th generation (ERA5) global reanalysis with the observations from McMurdo Station revealed a year-round deficit in DLW of approximately 50 Wm(-2) in marine air masses due to model shortages in supercooled cloud liquid water. A comparison with the surface DLW radiation observations from the Ocean Observatories Initiative mooring in the South Pacific at 54.08 degrees S, 89.67 degrees W, for the time period January 2016-November 2018, confirms approximately 20 Wm(-2) deficit in DLW in ERA5 well north of the sea-ice edge. Using a regional ocean model, we show that when DLW is artificially increased by 50 Wm(-2) in the simulation driven by ERAS atmospheric forcing, the predicted sea ice growth agrees much better with the observations. A wide variety of sensitivity tests show that the anomalously large, predicted sea-ice extent is not due to limitations in the ocean model and that by implication the cause resides with the atmospheric forcing.}, keywords = {Antarctic subseasonal sea ice predictability, coupled modeling of the Southern Ocean, downward longwave radiation deficit, model, ocean, polar weather research, shelf}, issn = {1748-9326}, doi = {10.1088/1748-9326/ac7d66}, url = {https://iopscience.iop.org/article/10.1088/1748-9326/ac7d66}, author = {Cerovecki, Ivana and Sun, Rui and Bromwich, David H. and Zou, Xun and Mazloff, Matthew R. and Wang, Sheng-Hung} } @article {gawarkiewicz_increasing_2022, title = {Increasing Frequency of Mid-Depth Salinity Maximum Intrusions in the Middle Atlantic Bight}, journal = {Journal of Geophysical Research - Oceans}, year = {2022}, abstract = { Shelfbreak exchange processes have been studied extensively in the Middle Atlantic Bight. An important process occurring during stratified conditions is the Salinity Maximum Intrusion. These features are commonly observed at the depth of the seasonal pycnocline, and less frequently at the surface and bottom. Data collected from NOAA{\textquoteright}s National Marine Fisheries Service Ecosystem Monitoring program as well as data collected from the fishing industry in Rhode Island show that the middepth intrusions are now occurring much more frequently than was reported in a previous climatology of the intrusions (Lentz, 2003, https:// doi.org/10.1029/2003JC001859). The intrusions have a greater salinity difference from ambient water and penetrate large distances shoreward of the shelf break relative to the earlier climatology. The longer term data from the Ecosystem Monitoring program indicates that the increase in frequency occurred in 2000, and thus may be linked to a recent regime shift in the annual formation rate of Warm Core Rings by the Gulf Stream. Given the increased frequency of these salty intrusions, it will be necessary to properly resolve this process in numerical simulations in order to account for salt budgets for the continental shelf and slope.}, keywords = {continental shelf processes, hydrography, intrusion, middle Atlantic bight, shelfbreak front, warm core ring}, issn = {2169-9275}, doi = {10.1029/2021jc018233}, author = {Gawarkiewicz, G and Fratantoni, P and Bahr, F and Ellertson, A} } @article {bazin_initial_2022, title = {Initial results from a hydroacoustic network to monitor submarine lava flows near Mayotte Island}, journal = {Comptes Rendus. G{\'e}oscience}, volume = {354}, number = {S2}, year = {2022}, pages = {1{\textendash}17}, abstract = {In 2019, a new underwater volcano was discovered at 3500 m below sea level (b.s.l.), 50 km east of Mayotte Island in the northern part of the Mozambique Channel. In January 2021, the submarine eruption was still going on and the volcanic activity, along with the intense seismicity that accompanies this crisis, was monitored by the recently created REVOSIMA (MAyotte VOlcano and Seismic Monitoring) network. In this framework, four hydrophones were moored in the SOFAR channel in October 2020. Surrounding the volcano, they monitor sounds generated by the volcanic activity and the lava flows. The first year of hydroacoustic data evidenced many earthquakes, underwater landslides, large marine mammal calls, along with anthropogenic noise. Of particular interest are impulsive signals that we relate to steam bursts during lava flow emplacement. A preliminary analysis of these impulsive signals (ten days in a year, and only one day in full detail) reveals that lava emplacement was active when our monitoring started, but faded out during the first year of the experiment. A systematic and robust detection of these specific signals would hence contribute to monitor active submarine eruptions in the absence of seafloor deep-tow imaging or swath-bathymetry surveys of the active area.}, issn = {1778-7025}, doi = {10.5802/crgeos.119}, url = {https://comptes-rendus.academie-sciences.fr/geoscience/articles/10.5802/crgeos.119/}, author = {Bazin, Sara and Royer, Jean-Yves and Dubost, Flavie and Paquet, Fabien and Loubrieu, Beno{\^\i}t and Lavayssi{\`e}re, Aude and Deplus, Christine and Feuillet, Nathalie and Jacques, {\'E}ric and Rinnert, Emmanuel and Thinon, Isabelle and Lebas, {\'E}lodie and Pierre, Delphine and Retailleau, Lise and Saurel, Jean-Marie and Sukhovich, Alexey and Bonnet, Robin and Group, the REVOSIMA} } @article {de_santis_insea_2022, title = {InSEA Project: Initiatives in Supporting the Consolidation and Enhancement of the EMSO Infrastructure and Related Activities}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2022}, note = {Place: Lausanne Publisher: Frontiers Media Sa WOS:000812864000001}, month = {jun}, pages = {846701}, abstract = {The InSEA project ("Initiatives in Supporting the consolidation and enhancement of the EMSO research infrastructure consortium (ERIC) and related Activities") has the objective, as the full name of the project indicates, to consolidate and strengthen the infrastructures concerning the EMSO ("European Multidisciplinary Seafloor and water column Observatory") ERIC (European Research Infrastructure Consortium) and all those technical-scientific activities related to it. In particular, the project is upgrading localized and distributed marine infrastructures, laboratories, observatories and spatial measurement activities in Southern Italian seas to support those activities of surveys in fixed time series points of observation of EMSO ERIC. The project is developing according to six implementation Objectives of Research (OR) that involve four National research Institutions: INGV, ISPRA, OGS and Anton Dohrn Zoological Station of Naples. The paper illustrates with more details the relevant objectives of the InSEA project and its most significant implementation phases.}, keywords = {campi flegrei, deep sea, geostar, OBS (ocean bottom seismometer), ocean bottom magnetometer, sea-floor, seafloor observatory, shallow-water, smart cable}, doi = {10.3389/fmars.2022.846701}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2022.846701/full}, author = {De Santis, Angelo and Chiappini, Massimo and Marinaro, Giuditta and Guardato, Sergio and Conversano, Fabio and D{\textquoteright}Anna, Giuseppe and Di Mauro, Domenico and Cardin, Vanessa and Carluccio, Roberto and Rende, Sante Francesco and Giordano, Raffaele and Rossi, Lorenzo and Simeone, Francesco and Giacomozzi, Emanuele and Fertitta, Gioacchino and Costanza, Antonio and Donnarumma, GianPaolo and Riccio, Rosario and Siena, Giuseppe and Civitarese, Giuseppe} } @article {268, title = {Integrating Multidisciplinary Observations in Vent Environments (IMOVE): Decadal Progress in Deep-Sea Observatories at Hydrothermal Vents}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2022}, month = {2022/05/13/}, abstract = {The unique ecosystems and biodiversity associated with mid-ocean ridge (MOR) hydrothermal vent systems contrast sharply with surrounding deep-sea habitats, however both may be increasingly threatened by anthropogenic activity (e.g., mining activities at massive sulphide deposits). Climate change can alter the deep-sea through increased bottom temperatures, loss of oxygen, and modifications to deep water circulation. Despite the potential of these profound impacts, the mechanisms enabling these systems and their ecosystems to persist, function and respond to oceanic, crustal, and anthropogenic forces remain poorly understood. This is due primarily to technological challenges and difficulties in accessing, observing and monitoring the deep-sea. In this context, the development of deep-sea observatories in the 2000s focused on understanding the coupling between sub-surface flow and oceanic and crustal conditions, and how they influence biological processes. Deep-sea observatories provide long-term, multidisciplinary time-series data comprising repeated observations and sampling at temporal resolutions from seconds to decades, through a combination of cabled, wireless, remotely controlled, and autonomous measurement systems. The three existing vent observatories are located on the Juan de Fuca and Mid-Atlantic Ridges (Ocean Observing Initiative, Ocean Networks Canada and the European Multidisciplinary Seafloor and water column Observatory). These observatories promote stewardship by defining effective environmental monitoring including characterizing biological and environmental baseline states, discriminating changes from natural variations versus those from anthropogenic activities, and assessing degradation, resilience and recovery after disturbance. This highlights the potential of observatories as valuable tools for environmental impact assessment (EIA) in the context of climate change and other anthropogenic activities, primarily ocean mining. This paper provides a synthesis on scientific advancements enabled by the three observatories this last decade, and recommendations to support future studies through international collaboration and coordination. The proposed recommendations include: i) establishing common global scientific questions and identification of Essential Ocean Variables (EOVs) specific to MORs, ii) guidance towards the effective use of observatories to support and inform policies that can impact society, iii) strategies for observatory infrastructure development that will help standardize sensors, data formats and capabilities, and iv) future technology needs and common sampling approaches to answer today{\textquoteright}s most urgent and timely questions.}, keywords = {COMMUNITY DYNAMICS}, doi = {10.3389/fmars.2022.866422}, author = {Matabos, Marjolaine and Barreyre, Thibaut and Juniper, S. Kim and Cannat, Mathilde and Kelley, Deborah and Alfaro-Lucas, Joan M. and Chavagnac, Valerie and Cola{\c c}o, Ana and Escartin, Javier and Escobar, Elva and Fornari, Daniel and Hasenclever, Jorg and Huber, Julie A. and Laes-Huon, Agathe and Lanteri, Nadine and Levin, Lisa Ann and Mihaly, Steve and Mittelstaedt, Eric and Pradillon, Florence and Sarradin, Pierre-Marie and Sarrazin, Jozee and Tomasi, Beatrice and Venkatesan, Ramasamy and Vic, Clement} } @article {chafik_irminger_2022, title = {Irminger Sea Is the Center of Action for Subpolar AMOC Variability}, journal = {Geophysical Research Letters}, volume = {49}, number = {17}, year = {2022}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022GL099133}, pages = {e2022GL099133}, abstract = {Significant societally important climate impacts can be caused by changes in the strength of the Atlantic Meridional Overturning Circulation (AMOC) at higher latitudes. Focusing on variability and long-term change of the subpolar North Atlantic (SPNA){\textemdash}a key AMOC action center{\textemdash}and using eastern OSNAP array observations, we identify a distinct density and sea-surface height signature of the AMOC strength in the Irminger Sea (2014{\textendash}2018), reinforced and extended with an ocean reanalysis (1993{\textendash}2018). Reconstruction of AMOC variability using Irminger Sea density shows strong control by the North Atlantic Oscillation on subpolar overturning on multiple timescales, achieved via the gyre circulation and waters from the Labrador Sea. Furthermore, the observed decrease of Irminger Sea density since the mid-twentieth century (1950{\textendash}2019) is suggestive of a long-term AMOC weakening of 2.2 Sv or 13\%, however, this trend remains statistically insignificant due to the large interannual and decadal variability of the SPNA.}, keywords = {AMOC, OSNAP}, issn = {1944-8007}, doi = {10.1029/2022GL099133}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022GL099133}, author = {Chafik, L. and Holliday, N. P. and Bacon, S. and Rossby, T.} } @article {284, title = {Long-Term Freezing Temperatures Frequency Change Effect on Wind Energy Gain (Eurasia and North America, 1950{\textendash}2019)}, journal = {Sustainability}, volume = {14}, year = {2022}, month = {2022/01//}, pages = {5630}, abstract = {The persistent freezing conditions in cold regions are the cause of ice accretion on mechanical and instrumental elements of wind turbines. Consequently, remarkable Annual Energy Production (AEP) losses are prone to occur in those wind farms. Following global expansion of wind energy, these areas have had increased study interest in recent years. The goal of these studies is an improved characterisation of the site for the installation of turbines, which could prevent unexpected high AEP losses due to ice accretion on them. In this context, this paper provides an estimation of the freezing temperatures frequency (FTF) at 100 m over latitudes and evaluates the changes during the last 70 years. To that end, hourly surface temperature data (2 m above surface) from the ERA5 reanalysis is used in the [50o N, 75o N] latitudinal belt for the period 1950{\textendash}2019. The obtained results show an average reduction of FTF hours of 72.5 h/decade for all the domain, reaching a maximum decrease of 621 h/decade on the southeast coast of Greenland and a 60\% annual reduction at a specific location in Scandinavia. In terms of AEP a maximum gain of more than 26\% would be projected, as categorised by the the International Energy Agency.}, keywords = {annual energy production, applied mathematics, ERA5, global warming, ice accretion, Temperature, wind energy potential}, isbn = {2071-1050}, doi = {10.3390/su14095630}, url = {https://www.mdpi.com/2071-1050/14/9/5630}, author = {Aizpurua-Etxezarreta, Maddi and Carreno-Madinabeitia, Sheila and Ulazia, Alain and S{\'a}enz, Jon and Saenz-Aguirre, Aitor} } @article {275, title = {Long-term noise interferometry analysis in the northeast Pacific Ocean}, journal = {The Journal of the Acoustical Society of America}, volume = {151}, year = {2022}, month = {2022/01//}, pages = {194 - 204}, abstract = {Long-term noise interferometry analysis is conducted over six years of data using two hydrophones on the Ocean Observatories Initiative Cabled Array. The two hydrophones are separated by 3.2 km and are bottom-mounted at 1500 m. We demonstrate the ability of ambient noise interferometry to reliably detect multi-path arrivals in the deep ocean from bottom-mounted hydrophones. An analysis of the multi-path arrival peak emergence is presented, as well as long-term trends of the signal-to-noise ratio of the arrival peaks. Last, we show that long-term ambient noise interferometry provides the opportunity for monitoring directional, coherent ambient sound such as the fin whale chorus.}, isbn = {0001-4966}, doi = {10.1121/10.0009232}, url = {https://asa.scitation.org/doi/full/10.1121/10.0009232}, author = {Ragland, John and Abadi, Shima and Sabra, Karim} } @article {fluegel_magnetization_2022, title = {The Magnetization of an Underwater Caldera: A Time-Lapse Magnetic Anomaly Study of Axial Seamount}, journal = {Geophysical Research Letters}, volume = {49}, number = {17}, year = {2022}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022GL100008}, pages = {e2022GL100008}, abstract = {Axial Seamount in the northeast Pacific erupted in 2015, 2011, and 1998. Although monitored by the Regional Cabled Array of the Ocean Observatory Initiative, few magnetic surveys have been conducted over the region. This study uses high-resolution magnetic data over the seamount collected by autonomous underwater vehicle Sentry during three years (2015, 2017, and 2020). The goal is to investigate whether there are temporal changes in the near-surface magnetic field observable over the time scale of one volcanic cycle. We compare magnetic maps from repeated tracklines from each year. We find maps of the yearly difference in magnetization show coherent patterns that are not random. The central region of the caldera has become more magnetic during recent years, suggesting cooling of the surficial lava flows since 2015. Sentry data are more sensitive to shallow crustal structure compared to sea surface data which show longer wavelength anomalies extending deeper into the crust.}, keywords = {magnetism, monitoring, seamounts, volcanic hazards, volcanology}, issn = {1944-8007}, doi = {10.1029/2022GL100008}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022GL100008}, author = {Fluegel, Bailey and Tivey, Maurice and Biasi, Joseph and Chadwick Jr., William W. and Nooner, Scott L.} } @article {frohle_major_2022, title = {Major sources of North Atlantic Deep Water in the subpolar North Atlantic from Lagrangian analyses in an eddy-rich ocean model}, journal = {Ocean Science}, volume = {18}, number = {5}, year = {2022}, note = {Publisher: Copernicus GmbH}, pages = {1431{\textendash}1450}, abstract = {The North Atlantic Deep Water (NADW) is a crucial component of the Atlantic meridional overturning circulation and is therefore an important factor of the climate system. In order to estimate the mean relative contributions, sources, and pathways of the NADW at the southern exit of the Labrador Sea, a Lagrangian particle experiment is performed. The particles were seeded according to the strength of the velocity field along the 53{\textopenbullet} N section and traced 40 years backward in time in the three dimensional velocity and hydrography field. The resulting transport pathways, their sources and corresponding transit timescales were inferred. Our experiment shows that, of the 30.1 Sv of NADW passing 53{\textopenbullet} N on average, the majority of this water is associated with a diapycnal mass flux without contact to the atmosphere, accounting for 14.3 Sv (48 \%), where 6.2 Sv originate from the Labrador Sea, compared to 4.7 Sv from the Irminger Sea. The second-largest contribution originates from the mixed layer with 7.2 Sv (24 \%), where the Labrador Sea contribution (5.9 Sv) dominates over the Irminger Sea contribution (1.0 Sv). Another 5.7 Sv (19 \%) of NADW crosses the Greenland{\textendash}Scotland Ridge within the NADW density class, where about two-thirds pass the Denmark Strait, while one-third crosses the Iceland{\textendash}Scotland Ridge. The NADW exported at 53{\textopenbullet} N is hence dominated by entrainment through the diapycnal mass flux and mixed-layer origin in the Labrador Sea.}, issn = {1812-0784}, doi = {10.5194/os-18-1431-2022}, url = {https://os.copernicus.org/articles/18/1431/2022/}, author = {Fr{\"o}hle, J{\"o}rg and Handmann, Patricia V. K. and Biastoch, Arne} } @article {283, title = {Management and Sustainable Exploitation of Marine Environments through Smart Monitoring and Automation}, journal = {Journal of Marine Science and Engineering}, volume = {10}, year = {2022}, month = {2022/02//}, pages = {297}, abstract = {Monitoring of aquatic ecosystems has been historically accomplished by intensive campaigns of direct measurements (by probes and other boat instruments) and indirect extensive methods such as aero-photogrammetry and satellite detection. These measurements characterized the research in the last century, with significant but limited improvements within those technological boundaries. The newest advances in the field of smart devices and increased networking capabilities provided by emerging tools, such as the Internet of Things (IoT), offer increasing opportunities to provide accurate and precise measurements over larger areas. These perspectives also correspond to an increasing need to promptly respond to frequent catastrophic impacts produced by drilling stations and intense transportation activities of dangerous materials over ocean routes. The shape of coastal ecosystems continuously varies due to increasing anthropic activities and climatic changes, aside from touristic activities, industrial impacts, and conservation practices. Smart buoy networks (SBNs), autonomous underwater vehicles (AUVs), and multi-sensor microsystems (MSMs) such as smart cable water (SCW) are able to learn specific patterns of ecological conditions, along with electronic {\textquotedblleft}noses{\textquotedblright}, permitting them to set innovative low-cost monitoring stations reacting in real time to the signals of marine environments by autonomously adapting their monitoring programs and eventually sending alarm messages to prompt human intervention. These opportunities, according to multimodal scenarios, are dramatically changing both the coastal monitoring operations and the investigations over large oceanic areas by yielding huge amounts of information and partially computing them in order to provide intelligent responses. However, the major effects of these tools on the management of marine environments are still to be realized, and they are likely to become evident in the next decade. In this review, we examined from an ecological perspective the most striking innovations applied by various research groups around the world and analyzed their advantages and limits to depict scenarios of monitoring activities made possible for the next decade.}, keywords = {aquaculture, buoy, coastal, connectivity, IoT, network, real time, transmission}, isbn = {2077-1312}, doi = {10.3390/jmse10020297}, url = {https://www.mdpi.com/2077-1312/10/2/297}, author = {Glaviano, Francesca and Esposito, Roberta and Di Cosmo, Anna and Esposito, Francesco and Gerevini, Luca and Ria, Andrea and Molinara, Mario and Bruschi, Paolo and Costantini, Maria and Zupo, Valerio} } @article {RN281, title = {Meanders of the West Greenland Current near Cape Farewell}, journal = {Deep Sea Research Part I Oceanographic Research Papers}, volume = {179}, year = {2022}, pages = {103664}, type = {Journal Article}, doi = {10.1016/j.dsr.2021.103664}, url = {https://app.dimensions.ai/details/publication/pub.1142443364 https://doi.org/10.1016/j.dsr.2021.103664}, author = {Pacini, Astrid and Pickart, Robert S.} } @article {fraser_north_2022, title = {North Atlantic Current and European Slope Current Circulation in the Rockall Trough Observed Using Moorings and Gliders}, journal = {Journal of Geophysical Research: Oceans}, volume = {127}, number = {12}, year = {2022}, note = {_eprint: https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2022JC019291}, pages = {e2022JC019291}, abstract = {The Rockall Trough (RT) accommodates the warmest and saltiest branch of the North Atlantic Current, which delivers water from the Gulf Stream into the marine environment around western Europe. In addition, the European Slope Current (ESC) carries warm water northward along the eastern boundary of the RT, and exchange between the ESC and the continental shelf is a dominant factor in determining the oceanographic conditions around the British Isles. However, the picture of the mean circulation and variability in the RT is still emerging, with a continuous observational campaign still in its relative infancy. The ESC, in particular, is poorly constrained by ship-based, mooring, and satellite observations. In this paper, we examine the RT circulation and volume transport using a temporally extended and spatially expanded observing network. Six years of continuous mooring occupation reveal that a large-amplitude, basin-scale freshening event, previously detected south of Iceland around 2015, impacted the RT around 2017. Geostrophic transport was greatly reduced during this period, driven by a concurrent subsurface temperature increase at the western boundary. The circulation regained strength during the latter part of the record. We gathered 110 glider transects over 22 months which capture the ESC velocity field in unprecedented detail. The data are sufficient to characterize both the mean state and the emergent seasonal variability of the ESC, and reveal the year-round presence of a southward countercurrent at depth. Variability in the strength and structure of this previously unstudied feature modulates net northward transport in the eastern boundary current system.}, keywords = {AMOC, Atlantic, climate, glider, OSNAP}, issn = {2169-9291}, doi = {10.1029/2022JC019291}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022JC019291}, author = {Fraser, Neil J. and Cunningham, Stuart A. and Drysdale, Lewis A. and Inall, Mark E. and Johnson, Clare and Jones, Sam C. and Burmeister, Kristin and Fox, Alan D. and Dumont, Estelle and Porter, Marie and Holliday, N. Penny} } @article {jackson_north_2022, title = {North Atlantic overturning and water mass transformation in CMIP6 models}, journal = {Climate Dynamics}, year = {2022}, abstract = {Climate models are important tools for investigating how the climate might change in the future, however recent observations have suggested that these models are unable to capture the overturning in subpolar North Atlantic correctly, casting doubt on their projections of the Atlantic Meridional Overturning Circulation (AMOC). Here we compare the overturning and surface water mass transformation in a set of CMIP6 models with observational estimates. There is generally a good agreement, particularly in the recent conclusion from observations that the mean overturning in the east (particularly in the Iceland and Irminger seas) is stronger than that in the Labrador Sea. The overturning in the Labrador Sea is mostly found to be small, but has a strong relationship with salinity: fresh models have weak overturning and saline models have stronger mean overturning and stronger relationships of the Labrador Sea overturning variability with the AMOC further south.We also find that the overturning reconstructed from surface flux driven water mass transformation is a good indicator of the actual overturning, though mixing can modify variability and shift signals to different density classes.}, keywords = {AMOC, CMIP6}, issn = {1432-0894}, doi = {10.1007/s00382-022-06448-1}, url = {https://doi.org/10.1007/s00382-022-06448-1}, author = {Jackson, L. C. and Petit, T.} } @article {fu_observation_2022, title = {Observation System Optimization of Offshore Acoustic Exploration for Estimating Submarine Geological Structures via Directivity Analysis}, journal = {Advances in Civil Engineering}, volume = {2022}, year = {2022}, note = {Publisher: Hindawi}, pages = {e1316439}, abstract = {To better understand the shallow sea geological information and avoid the risk caused by potential geo-disasters, the efficient offshore geological exploration methods are required. Better detection resolution can be obtained by using a spark source. As the foundation, the observation system plays an important role for geological detection. The influence of the variation of the parameters of the observation system on the detection accuracy is analysed theoretically. Then, the numerical simulations based on the finite difference method was applied, and imaging characteristics of observation system with different parameter were studied. For submarine acoustic exploration, the spark source with frequency over 200 Hz can obtain the clear reflections for geological interpretation; besides, the receiver array with the interval of 5 m{\textendash}10 m helps to obtain better wave signals when the buried depth of a geological body is less than 300 m, and the width is more than 10 m. Based on numerical simulations, the observation system was optimized and designed. The results of numerical examples show that the accurate position information of the structure can be obtained by using the observation system proposed in this paper. Different imaging performances are obtained by adjusting the parameters of the observation system. On this basis, combined with directivity analysis, the optimal observation system parameters are proposed. Finally, the proposed observation system is used to image the fault model. The research results of this paper can provide reference for the observation system design in similar projects.}, issn = {1687-8086}, doi = {10.1155/2022/1316439}, url = {https://www.hindawi.com/journals/ace/2022/1316439/}, author = {Fu, Chao and Hao, Lei and Zhou, Pengfei and Chen, Lei and Xu, Xiaobin and Wang, Kai and Sun, Miaojun} } @article {zhang_ocean_2022, title = {Ocean observation system design of mooring buoy and benthic node with electro-optical-mechanical cable}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2022}, abstract = {We designed a hybrid system named Mooring Buoys Observation System with Benthic Electro-optical-mechanical Cable (MBOSBC) for long-term seafloor and sea surface multi-parameter ocean observation. The electro-optical-mechanical (EOM) cable connects a sea surface buoy and a seafloor junction box so as to establish a transmission link of information and power between the sea surface and the seafloor. The EOM cable also plays the role of mooring tether to the MBOSBC and has to withstand the rigorous marine environment{\textemdash}experiencing mooring loads under complex marine environmental conditions for long periods of time. The data transmission of the system includes the EOM, satellite communication, wireless radio, and acoustic communication. The system power is generated by a wind turbine and solar panels and is transmitted to the seafloor junction box. An acoustic communication instrument is used to gather the sample data from other benthic nodes, such as seafloor landers, AUVs, and underwater gliders. MBOSBC is designed to operate from shallow water to deep sea, and to simultaneously monitor sea surface hydrology, meteorology, and water quality, as well as benthic temperature, pressure, salinity, currents, and seafloor video. We provide the MBOSBC architecture design, including the mechanical design, control, power, data transmission, and EOM cable. Finally, we describe the launch and recovery process of MBOSBC, as well as experimental results.}, issn = {2296-7745}, doi = {10.3389/fmars.2022.1018751}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2022.1018751}, author = {Zhang, Shaowei and Tian, Chuan and Zhou, Fenghua} } @mastersthesis {shajahan_ocean_2022, title = {OCEAN SOUND FIELD CHARACTERIZATION USING PROCESSING TECHNIQUES BASED ON NOISE SPATIAL COHERENCE}, volume = {Doctor of Philosophy}, year = {2022}, note = {Accepted: 2022-04-12T13:21:57Z}, month = {04/2022}, school = {DALHOUSIE UNIVERSITY}, type = {PhD}, address = {Halifax, Nova Scotia}, abstract = {The spatial coherence of ambient noise can be used for noise-based inversion studies using appropriate coherence models. The main findings of this thesis are presented in four chapters. In chapter 2, using a two-component noise coherence model (wind and shipping), an inversion scheme is developed to determine the relative and absolute contribution of frequency-dependent ship noise to the total sound field. A simple model of vertical coherence for a broadband acoustic source is developed in chapter 3 to understand the characteristics of the sound field produced by ships. In the fourth chapter, a map of vertical noise coherence is generated to study the environmental dependence of vertical coherence at the mesoscale. Finally, in chapter 5, a three-component (wind, close-range shipping, and distant wind and shipping) depth-dependent noise coherence model is developed to identify and partition the noise field in deep water.}, url = {https://DalSpace.library.dal.ca//handle/10222/81527}, author = {Shajahan, Najeem} } @article {lozier_overflow_2022, title = {Overflow Water Pathways in the North Atlantic}, journal = {Progress In Oceanography}, volume = {208}, year = {2022}, month = {aug}, pages = {102874}, abstract = {As part of the international Overturning in the Subpolar North Atlantic Program (OSNAP), 135 acoustically-tracked deep floats were deployed to track the spreading pathways of Iceland-Scotland Overflow Water (ISOW) and Denmark Strait Overflow Water (DSOW) from 2014 to 2018. These water masses, which originate in the Nordic Seas, are transported by the deepest branch of the Atlantic Meridional Overturning Circulation (AMOC). The OSNAP floats provide the first directly-observed, comprehensive Lagrangian view of ISOW and DSOW spreading pathways throughout the subpolar North Atlantic. The collection of OSNAP float trajectories, complemented by model simulations, reveals that their pathways are (a) not restricted to western boundary currents, and (b) remarkably different from each other in character. The spread of DSOW from the Irminger Sea is primarily via the swift deep boundary currents of the Irminger and Labrador Seas, whereas the spread of ISOW out of the Iceland Basin is slower and along multiple export pathways. The characterization of these Overflow Water pathways has important implications for our understanding of the AMOC and its variability. Finally, reconstructions of AMOC variability from proxy data, involving either the strength of boundary currents and/or the property variability of deep waters, should account for the myriad pathways of DSOW and ISOW, but particularly so for the latter.}, issn = {0079-6611}, doi = {10.1016/j.pocean.2022.102874}, author = {Lozier, M. Susan and Bower, Amy S. and Furey, Heather H. and Drouin, Kimberley L. and Xu, Xiaobiao and Zou, Sijia} } @article {278, title = {An overview of ambient sound using Ocean Observatories Initiative hydrophones}, journal = {The Journal of the Acoustical Society of America}, volume = {151}, year = {2022}, month = {2022/03//}, pages = {2085 - 2100}, abstract = {The Ocean Observatories Initiative (OOI) sensor network provides a unique opportunity to study ambient sound in the north-east Pacific Ocean. The OOI sensor network has five low frequency (Fs = 200 Hz) and six broadband (Fs = 64 kHz) hydrophones that have been recording ambient sound since 2015. In this paper, we analyze acoustic data from 2015 to 2020 to identify prominent features that are present in the OOI acoustic dataset. Notable features in the acoustic dataset that are highlighted in this paper include volcanic and seismic activity, rain and wind noise, marine mammal vocalizations, and anthropogenic sound, such as shipping noise. For all low frequency hydrophones and four of the six broadband hydrophones, we will present long-term spectrograms, median time-series trends for different spectral bands, and different statistical metrics about the acoustic environment. We find that 6-yr acoustic trends vary, depending on the location of the hydrophone and the spectral band that is observed. Over the course of six years, increases in spectral levels are seen in some locations and spectral bands, while decreases are seen in other locations and spectral bands. Last, we discuss future areas of research to which the OOI dataset lends itself.}, isbn = {0001-4966}, doi = {10.1121/10.0009836}, url = {https://asa.scitation.org/doi/full/10.1121/10.0009836}, author = {Ragland, John and Schwock, Felix and Munson, Matthew and Abadi, Shima} } @article {281, title = {Particle trajectories in an eastern boundary current using a regional ocean model at two horizontal resolutions}, journal = {Journal of Marine Systems}, volume = {233}, year = {2022}, month = {2022/09/01/}, pages = {103757}, abstract = {Lagrangian particle tracking (LPT) models are used to study the transport and dispersal of marine organisms. In LPT studies, the accuracy of the circulation is essential for nearshore habitats of Eastern Boundary Current (EBC) regions that are areas of high productivity and economically important fisheries. We used the California Current System as an example of an EBC region, specifically the Oregon coast located in the northern California Current System because it has distinct upwelling and downwelling regimes and variable shelf width. More specifically, we developed and applied a LPT model to compare and contrast particle drift patterns during the spring transition as it is an important period for spawning. We contrasted years (2016{\textendash}18) using Regional Ocean Modeling System (ROMS) with different horizontal spatial resolutions (2~km, 250~m). Lagrangian particles experience stronger downward velocities and displacements to greater depths in the 250~m ROMS simulations that used a finer resolution bathymetry. Consequently, retention along the Oregon coast increases in the 250~m ROMS compared to the 2~km ROMS. After 10~days, 37\%{\textendash}83\% of particles forced with the 2~km ROMS remain in the model domain, compared to 61\%{\textendash}86\% of particles remaining when using the 250~m ROMS. Particles in the 250~m ROMS are advected to depth at specific times and locations for each simulated year, coinciding with the location and timing of a strong and shallow alongshore undercurrent that is not present in the 2~km ROMS. Additionally, ageostrophic dynamics close to shore, in the bottom boundary layer, and around headlands emerge in the 250~m resolution model, while they are at best poorly resolved in the 2~km resolution case. We conclude that the higher horizontal model resolution and bathymetry used in the 250~m ROMS generates well-resolved mesoscale and submesoscale features (e.g., surface, subsurface, and nearshore jet) that vary annually. These physical features are significantly different than those modeled by the 2~km model and may be responsible for these differences in particle dispersal. These results have implications for modeling the dispersal, growth, and development of coastal organisms with dispersing early life stages.}, keywords = {coastal oceanography, Eastern boundary currents, Lagrangian particle tracking models, Oregon coast, ROMS, Spatial resolution}, isbn = {0924-7963}, doi = {10.1016/j.jmarsys.2022.103757}, url = {https://www.sciencedirect.com/science/article/pii/S0924796322000586}, author = {Wong-Ala, Jennifer A. T. K. and Ciannelli, Lorenzo and Durski, Scott M. and Spitz, Yvette} } @article {farghal_potential_2022, title = {The Potential of Using Fiber Optic Distributed Acoustic Sensing (DAS) in Earthquake Early Warning Applications}, journal = {Bulletin of the Seismological Society of America}, volume = {112}, number = {3}, year = {2022}, month = {apr}, pages = {1416{\textendash}1435}, abstract = {As the seismological community embraces fiber optic distributed acoustic sensing (DAS), DAS arrays are becoming a logical, scalable option to obtain strain and ground-motion data for which the installation of seismometers is not easy or cheap, such as in dense offshore arrays. The potential of strain data in earthquake early warning (EEW) applications has been recently demonstrated using records from borehole strainmeters (BSMs). However, current BSM networks are sparse, installing more BSMs is expensive and often impractical, and BSMs have the same limitations in offshore environments as other traditional seismic instruments. Here, we aim to provide a road map about how DAS data could be used in existing EEW applications, using the ShakeAlert EEW System for the West Coast of the United States as an example. We review the data requirements for EEW systems, examine ways in which strain-derived ground-motion data can be incorporated into such systems without significant modifications, and determine what is still needed for full utilization of DAS data in these applications. Importantly, EEW algorithms require ground-motion amplitude information for rapid earthquake source characterization; thus, accurate strain amplitude observations, not only phase information, are necessary for deriving these ground-motion metrics from DAS data. To obtain high-quality ground-motion observations, EEW-compatible DAS arrays need to be multicomponent, well coupled, and low noise. We suggest ways to achieve such data requirements using existing DAS technology and discuss areas in which further research is needed to optimize DAS array performance for EEW.}, issn = {0037-1106}, doi = {10.1785/0120210214}, url = {https://doi.org/10.1785/0120210214}, author = {Farghal, Noha S. and Saunders, Jessie K. and Parker, Grace A.} } @article {274, title = {Primary Productivity in the Mid-Atlantic Bight: Is the Shelf Break a Location of Enhanced Productivity?}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2022}, month = {2022///}, abstract = {Estimates of primary production represent the input of carbon into food webs, as well as the initial step in the biological pump. For the past 60 years, much of the productivity information has been obtained using measurements of 14C-bicarbonate removal during simulated in situ incubations. However, such measurements often do not reflect the complexity of the environment, and also suffer from uncertainties, biases and limitations. A vertically resolved bio-optical model has been used to estimate productivity based on profiles commonly assessed in oceanographic investigations, but comparisons with simultaneous measurements of 14C-uptake are limited. We conducted three cruises off the coast of New England that included sampling continental shelf waters, the shelf-break region, and deeper waters at scales of 7 km, all of which had productivity estimated by a vertically resolved productivity model as well as by traditional 14C-uptake measurements using simulated in situ techniques. We found that the vertically resolved bio-optical model gave results that appear to be more robust and resolved productivity at smaller vertical and horizontal scales, and seem less biased by some of the uncertainties in 14C-uptake measurements. Both estimates suggest that the New England waters are highly productive due to a variety of biological and physical processes occurring at different times of the year, but there was no consistent stimulation at the shelf break over the time scales of these estimates.}, isbn = {2296-7745}, doi = {10.3389/fmars.2022.824303}, url = {https://www.frontiersin.org/article/10.3389/fmars.2022.824303}, author = {Ma, Jiejie and Smith, Walker O.} } @article {decourcy_real-time_2022, title = {Real-time joint ocean acoustics and circulation modeling in the 2021 New England Shelf Break Acoustics experiment (L)}, journal = {The Journal of the Acoustical Society of America}, volume = {152}, number = {5}, year = {2022}, note = {Publisher: Acoustical Society of America}, pages = {2859{\textendash}2862}, abstract = {During the spring of 2021, a coordinated multi-vessel effort was organized to study physical oceanography, marine geology and biology, and acoustics on the northeast United States continental shelf, as part of the New England Shelf Break Acoustics (NESBA) experiment. One scientific goal was to establish a real-time numerical model aboard the research vessel with high spatial and temporal resolution to predict the oceanography and sound propagation within the NESBA study area. The real-time forecast model performance and challenges are reported in this letter without adjustment or re-simulation after the cruise. Future research directions for post-experiment studies are also suggested.}, issn = {0001-4966}, doi = {10.1121/10.0015139}, url = {https://asa.scitation.org/doi/10.1121/10.0015139}, author = {DeCourcy, Brendan J. and Lin, Ying-Tsong and Zhang, Weifeng Gordon and Ozanich, Emma Reeves and Kukshtel, Natalie and Siderius, Martin and Gawarkiewicz, Glen and Forsyth, Jacob} } @article {boss_recommendations_2022, title = {Recommendations for Plankton Measurements on OceanSITES Moorings With Relevance to Other Observing Sites}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2022}, abstract = {Measuring plankton and associated variables as part of ocean time-series stations has the potential to revolutionize our understanding of ocean biology and ecology and their ties to ocean biogeochemistry. It will open temporal scales (e.g., resolving diel cycles) not typically sampled as a function of depth. In this review we motivate the addition of biological measurements to time-series sites by detailing science questions they could help address, reviewing existing technology that could be deployed, and providing examples of time-series sites already deploying some of those technologies. We consider here the opportunities that exist through global coordination within the OceanSITES network for long-term (climate) time series station in the open ocean. Especially with respect to data management, global solutions are needed as these are critical to maximize the utility of such data. We conclude by providing recommendations for an implementation plan.}, issn = {2296-7745}, doi = {10.3389/fmars.2022.929436}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2022.929436}, author = {Boss, Emmanuel and Waite, Anya M. and Karstensen, Johannes and Trull, Tom and Muller-Karger, Frank and Sosik, Heidi M. and Uitz, Julia and Acinas, Silvia G. and Fennel, Katja and Berman-Frank, Ilana and Thomalla, Sandy and Yamazaki, Hidekatsu and Batten, Sonia and Gregori, Gerald and Richardson, Anthony J. and Wanninkhof, Rik} } @article {chen_research_2022, title = {Research on an Extensible Monitoring System of a Seafloor Observatory Network in Laizhou Bay}, journal = {Journal of Marine Science and Engineering}, volume = {10}, number = {8}, year = {2022}, note = {Number: 8 Publisher: Multidisciplinary Digital Publishing Institute}, month = {aug}, pages = {1051}, abstract = {An extensible remote monitoring system for a seafloor observatory network in Laizhou Bay was established to realize long-term, continuous and on-line monitoring for a marine ranching environment. This paper deals with data communication, device management and data quality control. A control model is introduced that is structured into four layers, enabling bidirectional information flow. Based on the control model, the standardized communication protocol and device object model-oriented dynamic management method are designed as plug-and-play, for data processing and control of a large number of devices. An improved data quality control method is proposed to reduce the data error rate. The monitoring system was developed based on socket network programming, MySQL database technologies and modular ideas. The seafloor observatory network was successfully deployed in Laizhou Bay marine ranching. The experimental results demonstrate that the monitoring system obtains better performance. The proposed algorithms can also be used in many other similar systems with adaptive requirements.}, keywords = {data communication, data quality control, device management, marine ranching, remote monitoring, seafloor observatory network}, issn = {2077-1312}, doi = {10.3390/jmse10081051}, url = {https://www.mdpi.com/2077-1312/10/8/1051}, author = {Chen, Jie and Liu, Hailin and Lv, Bin and Liu, Chao and Zhang, Xiaonan and Li, Hui and Cao, Lin and Wan, Junhe} } @article {272, title = {The Role of the Irminger Current in the Irminger Sea Northward Transport Variability}, journal = {Journal of Geophysical Research: Oceans}, volume = {127}, year = {2022}, month = {2022///}, pages = {e2021JC018188}, abstract = {The Irminger Current (IC) on the western flank of the Reykjanes Ridge is an important contributor to the northward transport in the Atlantic Meridional Overturning Circulation. Here, we combine 28 years of Copernicus Marine Environment Monitoring Service (CMEMS) ocean reanalysis data with 6 years of mooring data to investigate variability in volume transport of the IC. We found a mean volume transport for the IC of 11.6 Sv between 1993 and 2020 revealing the dominance of the IC in the total Irminger Sea northward volume transport (20.3 Sv). We found a significant decrease (-3.7 Sv) in volume transport of the IC until 2011 followed by a steeper (but shorter, leading to +2.7 Sv) increase until 2020. These changes across the Irminger Sea section are dominated by the IC, which in turn are driven by changes in the density gradient across the Irminger Sea related to convection. On decadal and interannual time scales the IC volume transport is well correlated with the decrease in the sea surface height difference over the basin. In 2019, a temporary intensification of the western IC core led to an exceptionally strong volume transport of the IC with 20 Sv. This was caused by density changes within the IC boundaries due to the presence of mesoscale eddies. Thus, IC transport variability is a superposition of basin-wide to local processes that influence the velocity field on different time scales.}, keywords = {AMOC, convection, Irminger Current, Irminger Sea, OSNAP}, isbn = {2169-9291}, doi = {10.1029/2021JC018188}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021JC018188}, author = {Fried, Nora and de Jong, M. Femke} } @article {nomikou_santory_2022, title = {SANTORY: SANTORini{\textquoteright}s Seafloor Volcanic ObservatorY}, journal = {Frontiers in Marine Science}, volume = {9}, year = {2022}, abstract = {Submarine hydrothermal systems along active volcanic ridges and arcs are highly dynamic, responding to both oceanographic (e.g., currents, tides) and deep-seated geological forcing (e.g., magma eruption, seismicity, hydrothermalism, and crustal deformation, etc.). In particular, volcanic and hydrothermal activity may also pose profoundly negative societal impacts (tsunamis, the release of climate-relevant gases and toxic metal(loid)s). These risks are particularly significant in shallow (<1000m) coastal environments, as demonstrated by the January 2022 submarine paroxysmal eruption by the Hunga Tonga-Hunga Ha{\textquoteright}apai Volcano that destroyed part of the island, and the October 2011 submarine eruption of El Hierro (Canary Islands) that caused vigorous upwelling, floating lava bombs, and natural seawater acidification. Volcanic hazards may be posed by the Kolumbo submarine volcano, which is part of the subduction-related Hellenic Volcanic Arc at the intersection between the Eurasian and African tectonic plates. There, the Kolumbo submarine volcano, 7 km NE of Santorini and part of Santorini{\textquoteright}s volcanic complex, hosts an active hydrothermal vent field (HVF) on its crater floor (\textasciitilde500m b.s.l.), which degasses boiling CO2{\textendash}dominated fluids at high temperatures (\textasciitilde265{\textdegree}C) with a clear mantle signature. Kolumbo{\textquoteright}s HVF hosts actively forming seafloor massive sulfide deposits with high contents of potentially toxic, volatile metal(loid)s (As, Sb, Pb, Ag, Hg, and Tl). The proximity to highly populated/tourist areas at Santorini poses significant risks. However, we have limited knowledge of the potential impacts of this type of magmatic and hydrothermal activity, including those from magmatic gases and seismicity. To better evaluate such risks the activity of the submarine system must be continuously monitored with multidisciplinary and high resolution instrumentation as part of an in-situ observatory supported by discrete sampling and measurements. This paper is a design study that describes a new long-term seafloor observatory that will be installed within the Kolumbo volcano, including cutting-edge and innovative marine-technology that integrates hyperspectral imaging, temperature sensors, a radiation spectrometer, fluid/gas samplers, and pressure gauges. These instruments will be integrated into a hazard monitoring platform aimed at identifying the precursors of potentially disastrous explosive volcanic eruptions, earthquakes, landslides of the hydrothermally weakened volcanic edifice and the release of potentially toxic elements into the water column.}, issn = {2296-7745}, doi = {10.3389/fmars.2022.796376}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2022.796376}, author = {Nomikou, Paraskevi and Polymenakou, Paraskevi N. and Rizzo, Andrea Luca and Petersen, Sven and Hannington, Mark and Kilias, Stephanos Pantelis and Papanikolaou, Dimitris and Escartin, Javier and Karantzalos, Konstantinos and Mertzimekis, Theodoros J. and Antoniou, Varvara and Krokos, Mel and Grammatikopoulos, Lazaros and Italiano, Francesco and Caruso, Cinzia Giuseppina and Lazzaro, Gianluca and Longo, Manfredi and Scir{\'e} Scappuzzo, Sergio and D{\textquoteright}Alessandro, Walter and Grassa, Fausto and Bejelou, Konstantina and Lampridou, Danai and Katsigera, Anna and Dura, Anne} } @article {le_bras_slantwise_2022, title = {Slantwise Convection in the Irminger Sea}, journal = {Journal of Geophysical Research: Oceans}, volume = {127}, number = {10}, year = {2022}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022JC019071}, pages = {e2022JC019071}, abstract = {The subpolar North Atlantic is a site of significant carbon dioxide, oxygen, and heat exchange with the atmosphere. This exchange, which regulates transient climate change and prevents large-scale hypoxia throughout the North Atlantic, is thought to be mediated by vertical mixing in the ocean{\textquoteright}s surface mixed layer. Here we present observational evidence that waters deeper than the conventionally defined mixed layer are affected directly by atmospheric forcing in this region. When northerly winds blow along the Irminger Sea{\textquoteright}s western boundary current, the Ekman response pushes denser water over lighter water, potentially triggering slantwise convection. We estimate that this down-front wind forcing is four times stronger than air{\textendash}sea heat flux buoyancy forcing and can mix waters to several times the conventionally defined mixed layer depth. Slantwise convection is not included in most large-scale ocean models, which likely limits their ability to accurately represent subpolar water mass transformations and deep ocean ventilation.}, keywords = {13 Climate Action}, issn = {2169-9291}, doi = {10.1029/2022JC019071}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022JC019071}, author = {Le Bras, I. A.-A. and Callies, J. and Straneo, F. and Bil{\'o}, T. C. and Holte, J. and Johnson, H. L.} } @article {kurapov_slope_2022, title = {Slope and Shelf Flow Anomalies Off Oregon Influenced by the El Ni{\~n}o Remote Oceanic Mechanism in 2014{\textendash}2016}, journal = {Journal of Geophysical Research: Oceans}, volume = {127}, number = {11}, year = {2022}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022JC018604}, pages = {e2022JC018604}, abstract = {Outputs of the regional ocean circulation model are analyzed to demonstrate the measurable impact of the El Ni{\~n}o remote oceanic forcing mechanism along the US West Coast during the major heat wave period of 2014{\textendash}2016. The 2-km horizontal resolution model, based on the Regional Ocean Modeling System (ROMS), was run for the period of 2009{\textendash}2018. Though the model does not assimilate observations, it performs well by comparison with time series data explaining observed variability on temporal scales from several days to seasonal and interannual. The El Ni{\~n}o-related oceanic anomalies provided by a global state estimate are introduced in the regional model at the southern boundary at 24N. These propagate alongshore with coastally trapped waves (CTWs) and influence the variability off Oregon (41{\textdegree}{\textendash}46{\textdegree}N). In particular, CTWs are evident in the subsurface along-slope current, vs, and in the depth of the 26.5 kg m-3 isopycnal surface over the slope, z26.5. In summer 2014 and 2015, vs anomalies are positive (northward) and z26.5 anomalies are negative (deeper) along the US West Coast. In addition to the CTW patterns, z26.5 anomalies also exhibit slow-moving features associated with undercurrent widening, separation, and subsurface eddy variability. Over the Oregon shelf, El Ni{\~n}o conditions contributed to the sharp weakening of the southward alongshore current throughout the water column in July 2014 and 2015, despite the near-average southward, upwelling-favorable winds.}, keywords = {coastal ocean processes, El Nino, regional ocean model, shelf-interior ocean interactions}, issn = {2169-9291}, doi = {10.1029/2022JC018604}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022JC018604}, author = {Kurapov, Alexander L. and Rudnick, Daniel L. and Cervantes, Brandy T. and Risien, Craig M.} } @article {bakker_smart_2022, title = {Smart Oceans: Artificial intelligence and marine protected area governance}, journal = {Earth System Governance}, volume = {13}, year = {2022}, month = {aug}, pages = {100141}, abstract = {This article analyzes a novel example of emerging digitally-driven earth system governance in the field of marine biodiversity conservation: Artificial Intelligence-enabled, mobile marine protected areas (MMPAs). MMPAs are geographically dynamic, with mobile boundaries which change position as endangered species migrate through the ocean. This real-time, mobile, and potentially spatially ubiquitous form of ocean governance relies on digital hardware that collects data from various sources (e.g. nano-satellites, drones, environmental sensor networks, digital bioacoustics, marine tags, deep sea UAVs), combined with analytics such as machine learning algorithms, computer vision and ecological informatics techniques. MMPAs are justified on the basis of their ability to enable responsive, real-time adaptation to environmental variability, species mobility, and disturbance dynamics; hence, scientists and regulators are increasingly recommending the deployment of these AI-powered computational systems in the world{\textquoteright}s oceans.}, keywords = {artificial intelligence, Environmental sustainability, Governance, Machine learning, Marine protected areas}, issn = {2589-8116}, doi = {10.1016/j.esg.2022.100141}, url = {https://www.sciencedirect.com/science/article/pii/S2589811622000106}, author = {Bakker, Karen} } @article {howe_smart_2022, title = {SMART Subsea Cables for Observing the Earth and Ocean, Mitigating Environmental Hazards, and Supporting the Blue Economy}, journal = {Frontiers in Earth Science}, volume = {9}, year = {2022}, abstract = {The Joint Task Force, Science Monitoring And Reliable Telecommunications (JTF SMART) Subsea Cables, is working to integrate environmental sensors for ocean bottom temperature, pressure, and seismic acceleration into submarine telecommunications cables. The purpose of SMART Cables is to support climate and ocean observation, sea level monitoring, observations of Earth structure, and tsunami and earthquake early warning and disaster risk reduction, including hazard quantification. Recent advances include regional SMART pilot systems that are the first steps to trans-ocean and global implementation. Examples of pilots include: InSEA wet demonstration project off Sicily at the European Multidisciplinary Seafloor and water column Observatory Western Ionian Facility; New Caledonia and Vanuatu; French Polynesia Natitua South system connecting Tahiti to Tubaui to the south; Indonesia starting with short pilot systems working toward systems for the Sumatra-Java megathrust zone; and the CAM-2 ring system connecting Lisbon, Azores, and Madeira. This paper describes observing system simulations for these and other regions. Funding reflects a blend of government, development bank, philanthropic foundation, and commercial contributions. In addition to notable scientific and societal benefits, the telecommunications enterprise{\textquoteright}s mission of global connectivity will benefit directly, as environmental awareness improves both the integrity of individual cable systems as well as the resilience of the overall global communications network. SMART cables support the outcomes of a predicted, safe, and transparent ocean as envisioned by the UN Decade of Ocean Science for Sustainable Development and the Blue Economy. As a continuation of the OceanObs{\textquoteright}19 conference and community white paper (Howe et al., 2019, doi: 10.3389/fmars.2019.00424), an overview of the SMART programme and a description of the status of ongoing projects are given.}, issn = {2296-6463}, doi = {10.3389/feart.2021.775544}, url = {https://www.frontiersin.org/articles/10.3389/feart.2021.775544}, author = {Howe, Bruce M. and Angove, Michael and Aucan, J{\'e}rome and Barnes, Christopher R. and Barros, Jos{\'e} S. and Bayliff, Nigel and Becker, Nathan C. and Carrilho, Fernando and Fouch, Matthew J. and Fry, Bill and Jamelot, Anthony and Janiszewski, Helen and Kong, Laura S. L. and Lentz, Stephen and Luther, Douglas S. and Marinaro, Giuditta and Matias, Lu{\'\i}s Manuel and Rowe, Charlotte A. and Sakya, Andi E. and Salaree, Amir and Thiele, Torsten and Tilmann, Frederik J. and von Hillebrandt-Andrade, Christa and Wallace, Laura and Weinstein, Stuart and Wilcock, William} } @article {jackson_sonar_2022, title = {Sonar Observation of Heat Flux of Diffuse Hydrothermal Flows}, journal = {Earth and Space Science}, volume = {9}, number = {n/a}, year = {2022}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2021EA001974}, pages = {e2021EA001974}, abstract = {Previous work using multibeam sonar to map diffuse hydrothermal flows is extended to estimate the heat output of diffuse flows. In the first step toward inversion, temperature statistics are obtained from sonar data and compared to thermistor data in order to set the value of an empirical constant. Finally, a simple model is used to obtain heat-flux density from sonar-derived temperature statistics. The method is applied to data from the Cabled Observatory Vent Imaging Sonar (COVIS) deployed on the Ocean Observatories Initiative{\textquoteright}s Regional Cabled Array at the ASHES vent field on Axial Seamount. Inversion results are presented as maps of heat-flux density in MW/m2 and as time series of heat-flux density averaged over COVIS{\textquoteright} field of view.}, keywords = {Deep-Sea Hydrothermal, Heat flux, sonar}, issn = {2333-5084}, doi = {10.1029/2021EA001974}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2021EA001974}, author = {Jackson, Darrell and Bemis, Karen and Xu, Guangyu and Ivakin, Anatoliy} } @mastersthesis {mehta_spatial_2022, title = {Spatial and Temporal Heterogeneity in Net Community Production in the Crossshelf Direction of the Atlantic Northeastern Shelf}, volume = {Honors in Chemistry}, year = {2022}, month = {04/2022}, school = {Wellesley College}, type = {BS}, address = {Wellesley, MA}, abstract = {The ocean, via physical and biological processes, absorbs 25\% of anthropogenic CO2 emissions. Climate change, however, hampers the ocean{\textquoteright}s ability to sequester carbon. The Northeast U.S. Shelf Long-Term Ecological Research (NES-LTER) project works to understand how warmer temperatures and increased environmental variability, caused by climate change, affects planktonic food webs and the productivity of the Northeast U.S. Continental Shelf ecosystem. Gas tracers, such as O2/Ar ratios and triple oxygen isotopes, are used to quantify productivity in the form of Net Community Production (NCP) and Gross Oxygen Production (GOP), respectively. NCP represents the total amount of photosynthesis minus community respiration, whereas GOP is the total amount of oxygen produced from photosynthesis. Summer and winter data from eight NES-LTER cruises between 2018-2021 enables the analysis of spatial heterogeneity and small-scale variability in productivity rates on seasonal and annual timescales . Data reveals that NCP rates are highest at mid-shelf latitudes and are smaller than expected in coastal nearshore waters of the NES. We examine temperature, salinity, transport of deeper slope waters, benthic respiration consuming oxygen, phytoplankton community structure, GOP rates, and nutrient availability to better understand cross-shelf variability in NCP. We find that, in winter, respiration from the benthic component is likely to have lowered NCP in nearshore waters, resulting in the observed peaks at mid-shelf latitudes. In summer, patterns of NCP closely follow phytoplankton biovolume, suggesting that the mid-shelf peak in NCP is related to changes in phytoplankton community abundance or structure.}, url = {https://repository.wellesley.edu/islandora/object/ir\%3A1739/}, author = {Mehta, Arshia} } @article {silver_spatial_2022, title = {Spatial variability of movement, structure, and formation of Warm Core Rings in the Northwest Atlantic Slope Sea}, journal = {Journal of Geophysical Research - Oceans}, volume = {127}, number = {8}, year = {2022}, month = {aug}, pages = {e2022JC018737}, abstract = {Gulf Stream Warm Core Rings (WCRs) have important influences on the New England Shelf and marine ecosystems. A 10-year (2011{\textendash}2020) WCR dataset that tracks weekly WCR locations and surface areas is used here to identify the rings{\textquoteright} path and characterize their movement between 55 and 75{\textdegree}W. The WCR dataset reveals a very narrow band between 66 and 71{\textdegree}W along which rings travel almost due west along \~{}39{\textdegree}N across isobaths {\textendash} the {\textquotedblleft}Ring Corridor.{\textquotedblright} Then, west of the corridor, the mean path turns southwestward, paralleling the shelfbreak. The average ring translation speed along the mean path is 5.9~cm s-1. Long-lived rings (lifespan >150~days) tend to occupy the region west of the New England Seamount Chain (NESC) whereas short-lived rings (lifespan <150~days) tend to be more broadly distributed. WCR vertical structures, analyzed using available Argo float profiles indicate that rings that are formed to the west of the NESC have shallower thermoclines than those formed to the east. This tendency may be due to different WCR formation processes that are observed to occur along different sections of the Gulf Stream. WCRs formed to the east of the NESC tend to form from a pinch-off mechanism incorporating cores of Sargasso Sea water and a perimeter of Gulf Stream water. WCRs that form to the west of the NESC, form from a process called an aneurysm. WCRs formed through aneurysms comprise water mostly from the northern half of the Gulf Stream and are smaller than the classic pinch-off rings.}, keywords = {aneurysm, Eddies, Gulf Stream, ring formation, trajectories, warm core rings}, issn = {2169-9275}, doi = {10.1029/2022jc018737}, author = {Silver, Adrienne and Gangopadhyay, Avijit and Gawarkiewicz, Glen and Andres, Magdalena and Flierl, Glenn and Clark, Jenifer} } @mastersthesis {carlson_is_2022, title = {Is the tidal triggering of earthquakes at Axial Seamount predictive of eruptions?}, year = {2022}, note = {Accepted: 2022-04-19T21:27:49Z}, school = {University of Washington}, type = {Senior Thesis}, address = {Seattle, WA, USA}, abstract = {Scientists have long hypothesized that tidal forces can trigger earthquakes due to the change in stress along a fault. This phenomenon is called tidal triggering of earthquakes. My study investigated the tidal triggering of earthquakes at Axial Seamount, Juan de Fuca Ridge from the time of the last eruption in 2015, to the present. This study tests the validity of the correlation between tidal triggering and volcanic cycles. My hypothesis is that the fraction of earthquakes is highest at low tidal heights / phases, and that tidal triggering increases in strength over time, therefore a potential sign during the onset of an eruption. Using data from the Ocean Observatories Initiative Regional Cabled Array, and the Oregon State University Tidal Model, I interpolated the time of earthquakes with the tidal cycle. Data from an earthquake catalog was plotted against the tidal model. Results prove my hypothesis to be valid. On an annual basis, the highest percentage of earthquakes occur within 30{\textdegree} of lowest tide (180{\textdegree}), and the highest rate of earthquakes per hour occur between -2m to -1m tidal height. On average, the percentage of earthquakes between 150{\textdegree} to 210{\textdegree} increases annually with a slope 1.88 \%/y. Additionally, the relative rate of earthquakes at -2m to -1m increases by 0.24 per year. I propose that the Axial Seamount will erupt soon, given tidal triggering has increased in strength and current data reflects similar data to what was seen prior to the 2015 eruption.}, url = {https://digital.lib.washington.edu:443/researchworks/handle/1773/48372}, author = {Carlson, Anders} } @article {276, title = {Time series of hydrothermal vent fluid chemistry at Main Endeavour Field, Juan de Fuca Ridge: Remote sampling using the NEPTUNE cabled observatory}, journal = {Deep Sea Research Part I: Oceanographic Research Papers}, volume = {186}, year = {2022}, month = {2022/08/01/}, pages = {103809}, abstract = {Seafloor hydrothermal fluids play a critical role in regulating a wide range of geochemical and biological processes. Chemical and physical changes to venting fluids undoubtedly occur in response to geological events, at depth or near the seafloor, with corresponding effects on vent fluid chemistry, mineralization, and biological activity. However, the uncertain timing of such events makes it impractical to anticipate their occurrence. Thus, the temporal evolution of seafloor vent fluids and coexisting mineral deposits is most often inferred from observations made using conventional deep submergence assets that may be non-continuous for a specific vent field. The recent development of submarine volcanic observatories operated by Ocean Networks Canada (ONC) and the Ocean Observatory Initiative (OOI) in the U.S. that deliver power to instruments on the seafloor and communications via high-speed fiber optic cable permits real-time communication and monitoring of seafloor vents. Here, we describe the development and application of a remotely operated hydrothermal fluid sampler that enables repeat on-demand sampling of high-temperature vent fluids triggered through the internet. The sampler was deployed from September 2019 to June 2020~at the S\&M vent area, in the southern portion of Main Endeavour Field (MEF), Juan de Fuca Ridge, on ONC{\textquoteright}s NEPTUNE ocean observatory. Nine vent fluid samples were acquired over a period of nine months. Analyses of these samples confirm the moderately high-temperature origin of the source fluid, as indicated, for example, by dissolved chloride depletion relative to seawater (vapor-rich) and moderately high silica concentrations. These and other dissolved species, such as methane, a known hallmark of MEF vent fluids, are in excellent agreement with the reported composition of S\&M vent fluids over the past 15 years or more, suggesting overall chemical stability and rock-dominated alteration processes. On the other hand, short-term variability of dissolved Mg, sulfate and barium indicate entrainment of conductively heated and partially reacted seawater. Both before and after the incursion of the {\textquotedblleft}secondary{\textquotedblright} seawater derived fluid, however, samples reveal the lowest Mg and sulfate concentrations yet reported for seafloor hydrothermal vent fluid samples. Accordingly, these data provide new insight on the solubility of these and other elements coexisting with minerals close to the Axial Magma Chamber (AMC), from which the primary source fluid is ultimately derived. A separate noteworthy event characterized by \~{}20~{\textdegree}C decrease in temperature and associated 24{\textendash}77\% decrease in dissolved Fe concentration was observed toward the end of the deployment, with implications for hydrothermal transition metal fluxes and linked biogeochemical processes. On-demand remote acquisition of a continuous series of high-temperature vent fluid samples from a single vent permits the temporal evolution of heat and mass transfer processes to be studied with a heretofore unavailable perspective. Furthermore, deployment of this sampler within the NEPTUNE ocean observatory opens the door to future studies based on comparative analysis of contemporaneous datasets.}, keywords = {Cabled array, Main Endeavour Field, Ocean Networks Canada, Remote sampling, Seafloor hydrothermal vents}, isbn = {0967-0637}, doi = {10.1016/j.dsr.2022.103809}, url = {https://www.sciencedirect.com/science/article/pii/S0967063722001224}, author = {Seyfried, William E. and Tan, Chunyang and Wang, Xun and Wu, Shijun and Evans, Guy N. and Coogan, Laurence A. and Mih{\'a}ly, Steven F. and Lilley, Marvin D.} } @article {qin_toward_2022, title = {Toward Democratizing Access to Facilities Data: A Framework for Intelligent Data Discovery and Delivery}, journal = {Computing in Science \& Engineering}, volume = {24}, number = {3}, year = {2022}, note = {Conference Name: Computing in Science \& Engineering}, month = {may}, pages = {52{\textendash}60}, abstract = {Data collected by large-scale instruments, observatories, and sensor networks (i.e., science facilities) are key enablers of scientific discoveries in many disciplines. However, ensuring that these data can be accessed, integrated, and analyzed in a democratized and timely manner remains a challenge. In this article, we explore how state-of-the-art techniques for data discovery and access can be adapted to facilitate data and develop a conceptual framework for intelligent data access and discovery.}, keywords = {Data collection, Data models, Data transfer, Distributed databases, Observatories}, issn = {1558-366X}, doi = {10.1109/MCSE.2022.3179408}, author = {Qin, Yubo and Rodero, Ivan and Parashar, Manish} } @article {henson_uncertain_2022, title = {Uncertain response of ocean biological carbon export in a changing world}, journal = {Nature Geoscience}, volume = {15}, number = {4}, year = {2022}, pages = {248{\textendash}254}, abstract = {The transfer of organic carbon from the upper to the deep ocean by particulate export flux is the starting point for the long-term storage of photosynthetically fixed carbon. This {\textquoteleft}biological carbon pump{\textquoteright} is a critical component of the global carbon cycle, reducing atmospheric CO2 levels by ~200 ppm relative to a world without export flux. This carbon flux also fuels the productivity of the mesopelagic zone, including important fisheries. Here we show that, despite its importance for understanding future ocean carbon cycling, Earth system models disagree on the projected response of the global export flux to climate change, with estimates ranging from -41\% to +1.8\%. Fundamental constraints to understanding export flux arise because a myriad of interconnected processes make the biological carbon pump challenging to both observe and model. Our synthesis prioritizes the processes likely to be most important to include in modern-day estimates (particle fragmentation and zooplankton vertical migration) and future projections (phytoplankton and particle size spectra and temperature-dependent remineralization) of export. We also identify the observations required to achieve more robust characterization, and hence improved model parameterization, of export flux and thus reduce uncertainties in current and future estimates in the overall cycling of carbon in the ocean.}, issn = {1752-0894}, doi = {10.1038/s41561-022-00927-0}, author = {Henson, Stephanie A. and Laufkotter, Charlotte and Leung, Shirley and Giering, Sarah L. C. and Palevsky, Hilary I. and Cavan, Emma L.} } @article {279, title = {On using nonlinear wave interactions in multi-directional seas for energy conversion on the ocean floor}, journal = {Applied Ocean Research}, volume = {124}, year = {2022}, month = {2022/07/01/}, pages = {103193}, abstract = {This paper investigates possible utilization of energy in interacting surface waves on the seafloor. Theory suggests that resonant wave interactions in confused open seas can cause energetic downward traveling second-order pressure waves, which during stormy conditions can be large enough to excite seafloor microseisms (Longuet-Higgins, 1950). Our analysis of contemporaneous data from seafloor pressure and velocity sensors from an Ocean Observatories Initiative (OOI) installation in the Northern Pacific and collocated surface-wave hindcasts showed evidence of the theoretically predicted vertical resonances (Longuet-Higgins, 1950). We observed that area-averaged predicted dynamic pressures and particle velocities 200~m below the water surface and their measured counterparts 2.6~km below at the seafloor were well correlated at the predicted resonance frequencies. Our results further revealed occurrence of net vertical power transfer at resonance from surface to seafloor by means of the predicted double-frequency pressure waves. Motivated by these findings, we estimated year-long seafloor power availability at five selected deep-sea locations. Next, we evaluated upper bounds on potentially convertible area averaged yearly-mean power amounts by a small flexible sphere type device at the seafloor. At \~{}400 mW m-2 to \~{}15 Wm-2, these power levels could assist sensor operations on and from the deep ocean floor.}, keywords = {Deep ocean sensing, Interacting surface waves, Ocean Observatories Initiative, Seafloor energy, Wave energy}, isbn = {0141-1187}, doi = {10.1016/j.apor.2022.103193}, url = {https://www.sciencedirect.com/science/article/pii/S0141118722001353}, author = {Korde, Umesh A. and McBeth, Michael S.} } @article {biasi_volcano_2022, title = {Volcano Monitoring With Magnetic Measurements: A Simulation of Eruptions at Axial Seamount, Kilauea, B{\'a}r{\dh}arbunga, and Mount Saint Helens}, journal = {Geophysical Research Letters}, volume = {49}, number = {17}, year = {2022}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2022GL100006}, pages = {e2022GL100006}, abstract = {Monitoring of active volcanic systems is a challenging task due in part to the trade-offs between collection of high-quality data from multiple techniques and the high costs of acquiring such data. Here we show that magnetic data can be used to monitor volcanoes by producing similar data to gravimetric techniques at significantly lower cost. The premise of this technique is that magma and wall rock above the Curie temperature are magnetically {\textquotedblleft}transparent,{\textquotedblright} but not stationary within the crust. Subsurface movements of magma can affect the crustal magnetic field measured at the surface. We construct highly simplified magnetic models of four volcanic systems: Mount Saint Helens (1980), Axial Seamount (2015{\textendash}2020), Kilauea (2018), and B{\'a}r{\dh}arbunga (2014). In all cases, observed or inferred changes to the magmatic system would have been detectable by modern magnetometers. Magnetic monitoring could become common practice at many volcanoes, particularly in developing nations with high volcanic risk.}, keywords = {Hawaii, Iceland, magnetism, monitoring, volcanic hazards, volcanology}, issn = {1944-8007}, doi = {10.1029/2022GL100006}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2022GL100006}, author = {Biasi, Joseph and Tivey, Maurice and Fluegel, Bailey} } @article {desbruyeres_warming{\textendash}cooling_2022, title = {Warming-to-Cooling Reversal of Overflow-Derived Water Masses in the Irminger Sea During 2002-2021}, journal = {Geophysical Research Letters}, volume = {49}, number = {10}, year = {2022}, pages = {e2022GL098057}, abstract = {Shipboard hydrography along the A25-Ovide section (2002{\textendash}2018) is combined with a high-resolution mooring array (2014{\textendash}2020) and a regional fleet of Deep-Argo floats (2016{\textendash}2021) to describe temperature changes of overflow-derived water masses in the Irminger Sea. Removing dynamical influences enables to identify a new statistically significant trend reversal in Iceland Scotland Overflow Water (ISOW) and Denmark Strait Overflow Water (DSOW) core temperatures in the mid-2010s. A basin-wide cooling trend of -16 {\textpm} 6 m{\textdegree}C yr-1 during 2016{\textendash}2021{\textemdash}but reaching as strong as -44 {\textpm} 13 m{\textdegree}C yr-1 for DSOW in recent years{\textemdash}is found to interrupt a warming phase that was prevailing since the late 1990s. The absence of an apparent reversal in the Nordic Seas and the faster changes detected in DSOW compared to ISOW point out the entrainment of subpolar signals within the overflows near the Greenland-Iceland-Scotland sills as a most likely driver.}, issn = {0094-8276}, doi = {10.1029/2022GL098057}, author = {Desbruyeres, Damien G. and Bravo, Eva Prieto and Thierry, Virginie and Mercier, Herl{\'e} and Lherminier, Pascale and Cabanes, Cecile and Bilo, Tiago C. and Fried, Nora and de Jong, M. Femke} } @article {xu_acoustic_2021, title = {Acoustic and In-Situ Observations of Deep Seafloor Hydrothermal Discharge: An OOI Cabled Array ASHES Vent Field Case Study}, journal = {Earth and Space Science}, volume = {8}, number = {3}, year = {2021}, note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1029/2020EA001269}, pages = {e2020EA001269}, abstract = {The Cabled Observatory Vent Imaging Sonar (COVIS) was installed on the Ocean Observatories Initiative{\textquoteright}s Regional Cabled Array observatory at ASHES hydrothermal vent field on Axial Seamount in July 2018. The acoustic backscatter data recorded by COVIS in August{\textendash}September 2018, in conjunction with in situ temperature measurements, are used to showcase and verify the use of COVIS for long-term, quantitative monitoring of hydrothermal discharge. Specifically, sonar data processing generates three-dimensional backscatter images of the buoyant plumes above major sulfide structures and two-dimensional maps of diffuse flows within COVIS{\textquoteright}s field-of-view. The backscatter images show substantial changes of plume appearance and orientation that mostly reflect plume bending in the presence of ambient currents and potentially the variations of outflow fluxes. The intensity of acoustic backscatter decreases significantly for highly bent plumes as compared to nearly vertical plumes, reflecting enhanced mixing of plume fluids with seawater driven by ambient currents. A forward model of acoustic backscatter from a buoyancy-driven plume developed in this study yields a reasonable match with the observation, which paves the way for inversely estimating the source heat flux of a hydrothermal plume from acoustic backscatter measurements. The acoustic observations of diffuse flows show large temporal variations on time scales of hours to days, especially at tidal frequencies, but no apparent long-term trend. These findings demonstrate COVIS{\textquoteright}s ability to quantitatively monitor hydrothermal discharge from both focused and diffuse sources to provide the research community with key observational data for studying the linkage of hydrothermal activity with oceanic and geological processes.}, keywords = {acoustic, axial seamount, hydrothermal, imaging, observatory, sonar}, issn = {2333-5084}, doi = {10.1029/2020EA001269}, url = {https://onlinelibrary.wiley.com/doi/abs/10.1029/2020EA001269}, author = {Xu, Guangyu and Bemis, Karen and Jackson, Darrell and Ivakin, Anatoliy} } @article {RN247, title = {Assessing the performance of an ocean observing, analysis and forecast System for the Mid-Atlantic Bight using array modes}, journal = {Ocean Modelling}, volume = {164}, year = {2021}, type = {Journal Article}, issn = {1463-5003}, doi = {10.1016/j.ocemod.2021.101821}, author = {Moore, A. M. and Levin, J. and Arango, H. G. and Wilkin, J.} } @article {RN255, title = {At the Interface of Marine Disciplines: Use of Autonomous Seafloor Equipment for Studies of Biofouling Below the Shallow-Water Zone}, journal = {Oceanography}, volume = {34}, number = {3}, year = {2021}, type = {Journal Article}, doi = {10.5670/oceanog.2021.302}, url = {https://app.dimensions.ai/details/publication/pub.1139212561 https://tos.org/oceanography/assets/docs/34-3_chava.pdf}, author = {Chava, Alexandra and Institute of Oceanology, P. P. Shirshov and Gebruk, Anna and Kolbasova, Glafira and Krylov, Artem and Tanurkov, Alexei and Gorbuskin, Andrei and Konovalova, Olga and Migali, Dragosh and Ermilova, Yulia and Shabalin, Nikolay and Chava, Vladimir and Semiletov, Igor and Mokievsky, Vadim} } @article {RN245, title = {Biogenic sinking particle fluxes and sediment trap collection efficiency at Ocean Station Papa}, journal = {Elementa-Science of the Anthropocene}, volume = {9}, number = {1}, year = {2021}, type = {Journal Article}, issn = {2325-1026}, doi = {10.1525/elementa.2020.00122}, author = {Estapa, M. and Buesseler, K. and Durkin, C. A. and Omand, M. and Benitez-Nelson, C. R. and Roca-Marti, M. and Breves, E. and Kelly, R. P. and Pike, S.} } @article {RN204, title = {Bottom boundary layer oxygen fluxes during winter on the Oregon Shelf}, journal = {Journal of Geophysical Research - Oceans}, year = {2021}, type = {Journal Article}, abstract = {In this study, lander-based eddy covariance measurements made 30 cm above a sandy seafloor are combined with ocean-observing and ship-based measurements to evaluate magnitudes of oxygen fluxes within the bottom boundary layer (BBL) during winter on the Oregon shelf. The total oxygen fluxes observed at a mid-shelf station were -12.3 {\textpm} 7.6 and -18.6 {\textpm} 16.9 mmol m-2d-1 during February 2018 and January 2019 deployments, respectively, and -51.8 {\textpm} 34.9 mmol m-2d-1 during a deployment on the inner shelf in January 2019. These mean ({\textpm}SD) flux derivations are greater than fluxes determined previously at nearly the same locations during the summer upwelling season, which points to the activation of benthic respiration by winter wave-dominated BBL dynamics. To determine the direct flux contributions (or potential bias) at wave frequencies, a phase-based method of spectral decomposition was applied to separate wave-induced and turbulence-induced components of velocity and dissolved oxygen time-series. This approach identified 25.4, 18.6, and 23.3\% of the average total EC oxygen fluxes from the three deployments as carried by waves or possibly turbulence stretched by waves. Additionally, we observed evidence of large waves regularly resuspending sediments and transporting entrained particles past the EC sensors. We apply this evidence to infer that wave frequencies must also contribute significantly to the real spectral domain of benthic oxygen fluxes and that the total fluxes of this study reflect elevated oxygen consumption rates without artifacts. This assessment may not be true for all data sets and may be dependent on wave properties and the quality and treatment of the measurements.}, keywords = {bottom boundary layer, eddy covariance, Oregon shelf, oxygen fluxes, turbulence, waves}, doi = {10.1029/2020jc016828}, author = {Reimers, Clare E. and Fogaren, Kristen E.} } @article {RN264, title = {The cabled observatory vent imaging sonar deployed on the Ocean Observatories initiative{\textquoteright}s cabled array}, journal = {The Journal of the Acoustical Society of America}, volume = {150}, number = {4}, year = {2021}, pages = {a122-a122}, type = {Journal Article}, doi = {10.1121/10.0007839}, url = {https://app.dimensions.ai/details/publication/pub.1142688757}, author = {Xu, Guangyu and Jackson, Darrell R. and Bemis, Karen and Ivakin, Anatoliy N.} } @inbook {RN285, title = {Chapter 12 Ocean currents, heat transport, and climate}, booktitle = {Ocean Currents}, year = {2021}, pages = {497-520}, type = {Book Section}, doi = {10.1016/b978-0-12-816059-6.00010-3}, url = {https://app.dimensions.ai/details/publication/pub.1139551753}, author = {Marsh, Robert and van Sebille, Erik} } @article {RN249, title = {Characterizing underwater noise during rain at the northeast Pacific continental margin}, journal = {The Journal of the Acoustical Society of America}, volume = {149}, number = {6}, year = {2021}, pages = {4579-4595}, type = {Journal Article}, doi = {10.1121/10.0005440}, url = {https://app.dimensions.ai/details/publication/pub.1139189404 https://asa.scitation.org/doi/pdf/10.1121/10.0005440}, author = {Schwock, Felix and Abadi, Shima} } @article {RN244, title = {Concentrations, ratios, and sinking fluxes of major bioelements at Ocean Station Papa}, journal = {Elementa-Science of the Anthropocene}, volume = {9}, number = {1}, year = {2021}, type = {Journal Article}, issn = {2325-1026}, doi = {10.1525/elementa.2020.00166}, author = {Roca-Marti, M. and Benitez-Nelson, C. R. and Umhau, B. P. and Wyatt, A. M. and Clevenger, S. J. and Pike, S. and Horner, T. J. and Estapa, M. L. and Resplandy, L. and Buesseler, K. O.} } @article {RN238, title = {Diatom Hotspots Driven by Western Boundary Current Instability}, journal = {Geophysical Research Letters}, year = {2021}, type = {Journal Article}, abstract = {Climatic changes have decreased the stability of the Gulf Stream (GS), increasing the frequency at which its meanders interact with the Mid-Atlantic Bight (MAB) continental shelf and slope region. These intrusions are thought to suppress biological productivity by transporting low-nutrient water to the otherwise productive shelf edge region. Here we present evidence of widespread, anomalously intense subsurface diatom hotspots in the MAB slope sea that likely resulted from a GS intrusion in July 2019. The hotspots (at \~{}50 m) were associated with water mass properties characteristic of GS water (\~{}100 m); it is probable that the hotspots resulted from the upwelling of GS water during its transport into the slope sea, likely by a GS meander directly intruding onto the continental slope east of where the hotspots were observed. Further work is required to unravel how increasingly frequent direct GS intrusions could influence MAB marine ecosystems.}, doi = {10.1029/2020gl091943}, url = {https://app.dimensions.ai/details/publication/pub.1137908537}, author = {Oliver, Hilde and Zhang, Weifeng G. and Smith, Walker O. and Alatalo, Philip and Chappell, P. Dreux and Hirzel, Andrew J. and Selden, Corday R. and Sosik, Heidi M. and Stanley, Rachel H. R. and Zhu, Yifan and McGillicuddy, Dennis J.} } @article {RN283, title = {Direct and Indirect Pathways of Convected Water Masses and Their impacts on the Overturning Dynamics of the Labrador Sea}, journal = {Journal of Geophysical Research - Oceans}, volume = {126}, number = {1}, year = {2021}, type = {Journal Article}, doi = {10.1029/2020jc016654}, url = {https://app.dimensions.ai/details/publication/pub.1134037551 https://onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2020JC016654}, author = {Georgiou, Sotiria and Ypma, Stefanie L. and Br{\"u}ggemann, Nils and Sayol, Juan-Manuel and van der Boog, Carine G. and Spence, Paul and Pietrzak, Julie D. and Katsman, Caroline A.} } @article {RN295, title = {Distinct sources of interannual subtropical and subpolar Atlantic overturning variability}, journal = {Nature Geoscience}, volume = {14}, number = {7}, year = {2021}, pages = {491-495}, type = {Journal Article}, doi = {10.1038/s41561-021-00759-4}, url = {https://app.dimensions.ai/details/publication/pub.1138476478 http://nora.nerc.ac.uk/id/eprint/530907/1/Kostov_et_al_Third_Submission_NatGeo_REF.pdf}, author = {Kostov, Yavor and Johnson, Helen L. and Marshall, David P. and Heimbach, Patrick and Forget, Gael and Holliday, N. Penny and Lozier, M. Susan and Li, Feili and Pillar, Helen R. and Smith, Timothy} } @article {RN203, title = {Don{\textquoteright}t catch me if you can {\textendash} Using cabled observatories as multidisciplinary platforms for marine fish community monitoring: an in situ case study combining Underwater Video and environmental DNA data}, journal = {The Science of The Total Environment}, year = {2021}, pages = {145351}, type = {Journal Article}, abstract = {Cabled observatories are marine infrastructures equipped with biogeochemical and oceanographic sensors as well as High-Definition video and audio equipment, hence providing unprecedented opportunities to study marine biotic and abiotic components. Additionally, non-invasive monitoring approaches such as environmental DNA (eDNA) metabarcoding have further enhanced the ability to characterize marine life. Although the use of non-invasive tools beholds great potential for the sustainable monitoring of biodiversity and declining natural resources, such techniques are rarely used in parallel and understanding their limitations is challenging. Thus, this study combined Underwater Video (UV) with eDNA metabarcoding data to produce marine fish community profiles over a 2 months period in situ at a cabled observatory in the northeast Atlantic (SmartBay Ireland). By combining both approaches, an increased number of fish could be identified to the species level (total of 22 species), including ecologically and economically important species such as Atlantic cod, whiting, mackerel and monkfish. The eDNA approach alone successfully identified a higher number of species (59\%) compared to the UV approach (18\%), whereby 23\% of species were detected by both methods. The parallel implementation of point collection eDNA and time series UV data not only confirmed expectations of the corroborative effect of using multiple disciplines in fish community composition, but also enabled the assessment of limitations intrinsic to each technique including the identification of false-negative detections in one sampling technology relative to the other. This work showcased the usefulness of cabled observatories as key platforms for in situ empirical assessment of both challenges and prospects of novel technologies in aid to future monitoring of marine life. }, keywords = {Cabled observatory, Environmental DNA, Marine fish, Metabarcoding, Non-invasive monitoring, Underwater Video}, doi = {10.1016/j.scitotenv.2021.145351}, url = {https://app.dimensions.ai/details/publication/pub.1135067559}, author = {Mirimin, Luca and Desmet, Sam and Romero, David L{\'o}pez and Fernandez, Sara Fernandez and Miller, Dulaney L. and Mynott, Sebastian and Brincau, Alejandro Gonzalez and Stefanni, Sergio and Berry, Alan and Gaughan, Paul and Aguzzi, Jacopo} } @article {RN253, title = {Earthquake location and detection modeling for a future seafloor observatory along Mayotte\&$\#$x27;s volcanic ridge}, journal = {Journal of Volcanology and Geothermal Research}, volume = {418}, year = {2021}, pages = {107322}, type = {Journal Article}, doi = {10.1016/j.jvolgeores.2021.107322}, url = {https://app.dimensions.ai/details/publication/pub.1138943481 https://doi.org/10.1016/j.jvolgeores.2021.107322}, author = {Aiken, Chastity and Saurel, Jean-Marie and Foix, Oc{\'e}ane} } @article {RN274, title = {Ephemeral surface chlorophyll enhancement at the New England shelf break driven by Ekman restratification}, journal = {Journal of Geophysical Research - Oceans}, year = {2021}, type = {Journal Article}, doi = {10.1029/2021jc017715}, url = {https://app.dimensions.ai/details/publication/pub.1144229542}, author = {Oliver, Hilde and Zhang, Weifeng Gordon and Archibald, Kevin M. and Hirzel, Andrew J. and Smith, Walker O. and Sosik, Heidi M. and Stanley, Rachel H. R. and McGillicuddy, Dennis J.} } @article {RN273, title = {Geodetic Monitoring at Axial Seamount Since its 2015 Eruption Reveals a Waning Magma Supply and Tightly Linked Rates of Deformation and Seismicity}, journal = {Geochemistry Geophysics Geosystems}, year = {2021}, type = {Journal Article}, doi = {10.1029/2021gc010153}, url = {https://app.dimensions.ai/details/publication/pub.1144167182}, author = {Chadwick, William W. and Wilcock, William S. D. and Nooner, Scott L. and Beeson, Jeff W. and Sawyer, Audra M. and Lau, T. -K} } @article {RN259, title = {Global Wave Hindcasts Using the Observation-Based Source Terms: Description and Validation}, journal = {Journal of Advances in Modeling Earth Systems}, volume = {13}, number = {8}, year = {2021}, type = {Journal Article}, doi = {10.1029/2021MS002493}, author = {Liu, Q. X. and Babanin, A. V. and Rogers, W. E. and Zieger, S. and Young, I. R. and Bidlot, J. R. and Durrant, T. and Ewans, K. and Guan, C. L. and Kirezci, C. and Lemos, G. and MacHutchon, K. and Moon, I. and Rapizo, H. and Ribal, A. and Semedo, A. and Wang, J. J.} } @article {RN293, title = {Horizontal circulation across density surfaces contributes substantially to the long-term mean northern Atlantic Meridional Overturning Circulation}, journal = {Communications Earth \& Environment}, volume = {2}, number = {1}, year = {2021}, pages = {112}, type = {Journal Article}, doi = {10.1038/s43247-021-00182-y}, url = {https://app.dimensions.ai/details/publication/pub.1138686306 https://www.nature.com/articles/s43247-021-00182-y.pdf}, author = {Zhang, Rong and Thomas, Matthew} } @article {RN242, title = {The impact of remote sensing observations on cross-shelf transport estimates from 4D-Var analyses of the Mid-Atlantic Bight}, journal = {Advances in Space Research}, volume = {68}, number = {2}, year = {2021}, pages = {553-570}, type = {Journal Article}, abstract = {This paper explores the impact of the individual components of a coastal ocean observing system on estimates of the circulation derived from a state-of-the-art analysis and forecast system for the Mid-Atlantic Bight and Gulf of Maine. The foundation of these activities is the Regional Ocean Modeling System 4-dimensional variational (4D-Var) data assimilation platform, which is run in support of the Mid-Atlantic Regional Association Coastal Ocean Observing System as part of the U.S. Integrated Ocean Observing System. The specific focus of this study is on the impact of remote sensing observations from both space- and land-based platforms on estimates of cross-shelf transport in the vicinity of the National Science Foundation Ocean Observatories Initiative Pioneer array. Sea surface temperature (SST) and sea surface height (SSH) were found to have, on average, a similar impact on the transport estimates. However, during a typical 3-day 4D-Var assimilation cycle, approximately two orders of magnitude more observations of SST than SSH are used in the model, and closer analysis shows that each altimeter measurement has approximately 50 times more impact on the transport estimates than an individual SST observation. This highlights the value of altimetry data for ocean state estimation, and the significance of expanding the altimeter constellation. The observations that are most impactful of all are in situ measurements of temperature and salinity, which have typically 3{\textendash}4 times more impact than an individual SSH datum. A robust geographical distribution of the observation impacts emerges across a range of transport metrics which results from the combined influence of space-time dynamical interpolation and error covariance information within the 4D-Var system. The observation impact calculations suggest that High Frequency (HF) radar estimates of surface currents have relatively little direct influence on cross-shelf transport estimates. However, quantification of the sensitivity of these same estimates to changes in the observing system indicate that HF radar observations indirectly provide important information. This is understood in the current system by appealing to the idea of borrowing strength from the field of statistics in which some observations (satellite remote sensing in the case considered here) can borrow strength from other, seemingly less important observations.}, keywords = {4D-Var, Mid Atlantic Bight, Observation impact}, issn = {0273-1177}, doi = {10.1016/j.asr.2019.09.012}, author = {Levin, J. and Arango, H. G. and Laughlin, B. and Wilkin, J. and Moore, A. M.} } @article {RN206, title = {The Importance of Marine Research Infrastructures in Capturing Processes and Impacts of Extreme Events}, journal = {Frontiers in Marine Science}, volume = {08}, year = {2021}, pages = {626668}, type = {Journal Article}, abstract = {Extreme events have long been underestimated in the extent to which they shape the surface of our planet, our environment, its ecological integrity, and the sustainability of human society. Extreme events are by definition rarely observed, of significant impact and, as a result of their spatiotemporal range, not always easily predicted. Extremes may be short-term catastrophic events such as tsunamis, or long-term evolving events such as those linked to climate change; both modify the environment, producing irreversible changes or regime shifts. Whatever the driver that triggers the extreme event, the damages are often due to a combination of several processes and their impacts can affect large areas with secondary events (domino effect), whose effects in turn may persist well beyond the duration of the trigger event itself. Early studies of extreme events were limited to opportunistic approaches: observations were made within the context of naturally occurring events with high societal impact. Given that climate change is now moving us out of a relatively static climate regime during the development of human civilization, extreme events are now a function of underlying climate shifts overlain by catastrophic processes. Their impacts are often due to synergistic factors, all relevant in understanding process dynamics; therefore, an integrated methodology has become essential to enhance the reliability of new assessments and to develop strategies to mitigate societal impacts. Here we summarize the current state of extreme event monitoring in the marine system, highlighting the advantages of a multidisciplinary approach using Research Infrastructures for providing the temporal and spatial resolution required to monitor Earth processes and enhance assessment of associated impacts.}, keywords = {international cooperation, interoperability, marine extreme events, monitoring, multidisciplinary, research infrastructures}, doi = {10.3389/fmars.2021.626668}, url = {https://app.dimensions.ai/details/publication/pub.1136473721 https://www.frontiersin.org/articles/10.3389/fmars.2021.626668/pdf}, author = {Bue, Nadia Lo and Best, Mairi M. R. and Embriaco, Davide and Abeysirigunawardena, Dilumie and Beranzoli, Laura and Dewey, Richard K. and Favali, Paolo and Feng, Ming and Heesemann, Martin and Leijala, Ulpu and {\'O}{\textquoteright}Conchubhair, Diarmuid and Scherwath, Martin and Scoccimarro, Enrico and Wernberg, Thomas} } @article {RN263, title = {Industry Partnership: Lab on Chip Chemical Sensor Technology for Ocean Observing}, journal = {Frontiers in Marine Science}, volume = {8}, year = {2021}, pages = {697611}, type = {Journal Article}, doi = {10.3389/fmars.2021.697611}, url = {https://app.dimensions.ai/details/publication/pub.1142001447 http://dx.doi.org/10.3389/fmars.2021.697611}, author = {Mowlem, Matt and Beaton, Alexander and Pascal, Robin and Schaap, Allison and Loucaides, Socratis and Monk, Sam and Morris, Andrew and Cardwell, Christopher L. and Fowell, Sara E. and Patey, Matthew D. and L{\'o}pez-Garc{\'\i}a, Patricia} } @article {RN201, title = {Interannual and seasonal asymmetries in Gulf Stream Ring Formations from 1980 to 2019}, journal = {Scientific Reports}, volume = {11}, number = {1}, year = {2021}, pages = {2207}, type = {Journal Article}, abstract = {As the Gulf Stream separates from the coast, it sheds both Warm and Cold Core Rings between 75o and 55oW. We present evidence that this ring formation behavior has been asymmetric over both interannual and seasonal time-scales. After a previously reported regime-shift in 2000, 15 more Warm Core Rings have been forming yearly compared to 1980{\textendash}1999. In contrast, there have been no changes in the annual formation rate of the Cold Core Rings. This increase in Warm Core Ring production leads to an excess heat transfer of 0.10 PW to the Slope Sea, amounting to 7.7{\textendash}12.4\% of the total Gulf Stream heat transport, or 5.4{\textendash}7.3\% of the global oceanic heat budget at 30oN. Seasonally, more Cold Core Rings are produced in the winter and spring and more Warm Core Rings are produced in the summer and fall leading to more summertime heat transfer to the north of the Stream. The seasonal cycle of relative ring formation numbers is strongly correlated (r = 0.82) with that of the difference in upper layer temperatures between the Sargasso and Slope seas. This quantification motivates future efforts to understand the recent increasing influence of the Gulf Stream on the circulation and ecosystem in the western North Atlantic.}, doi = {10.1038/s41598-021-81827-y}, url = {https://app.dimensions.ai/details/publication/pub.1134854819 https://doi.org/10.1038/s41598-021-81827-y}, author = {Silver, Adrienne and Gangopadhyay, Avijit and Gawarkiewicz, Glen and Silva, E. Nishchitha S. and Clark, Jenifer} } @article {RN241, title = {Leveraging user access patterns and advanced cyberinfrastructure to accelerate data delivery from shared-use scientific observatories}, journal = {Future Generation Computer Systems-the International Journal of Escience}, volume = {122}, year = {2021}, pages = {14-27}, type = {Journal Article}, abstract = {With the growing number and increasing availability of shared-use instruments and observatories, observational data is becoming an essential part of application workflows and contributor to scientific discoveries in a range of disciplines. However, the corresponding growth in the number of users accessing these facilities coupled with the expansion in the scale and variety of the data, is making it challenging for these facilities to ensure their data can be accessed, integrated, and analyzed in a timely manner, and is resulting significant demands on their cyberinfrastructure (CI). In this paper, we present the design of a push-based data delivery framework that leverages emerging in-network capabilities, along with data pre-fetching techniques based on a hybrid data management model. Specifically, we analyze data access traces for two large-scale observatories, Ocean Observatories Initiative (OOI) and Geodetic Facility for the Advancement of Geoscience (GAGE), to identify typical user access patterns and to develop a model that can be used for data pre-fetching. Furthermore, we evaluate our data pre-fetching model and the proposed framework using a simulation of the Virtual Data Collaboratory (VDC) platform that provides in-network data staging and processing capabilities. The results demonstrate that the ability of the framework to significantly improve data delivery performance and reduce network traffic at the observatories{\textquoteright} facilities. }, keywords = {Collaboratory, Cyberinfrastructure, Data pre-fetching, Distributed data sharing, Distributed facilities, Observatories, Virtual Data}, issn = {0167-739X}, doi = {10.1016/j.future.2021.03.004}, author = {Qin, Y. B. and Rodero, I. and Simonet, A. and Meertens, C. and Reiner, D. and Riley, J. and Parashar, M.} } @article {RN208, title = {Leveraging user access patterns and advanced cyberinfrastructure to accelerate data delivery from shared-use scientific observatories}, journal = {Future Generation Computer Systems}, year = {2021}, type = {Journal Article}, abstract = {With the growing number and increasing availability of shared-use instruments and observatories, observational data is becoming an essential part of application workflows and contributor to scientific discoveries in a range of disciplines. However, the corresponding growth in the number of users accessing these facilities coupled with the expansion in the scale and variety of the data, is making it challenging for these facilities to ensure their data can be accessed, integrated, and analyzed in a timely manner, and is resulting significant demands on their cyberinfrastructure (CI). In this paper, we present the design of a push-based data delivery framework that leverages emerging in-network capabilities, along with data pre-fetching techniques based on a hybrid data management model. Specifically, we analyze data access traces for two large-scale observatories, Ocean Observatories Initiative (OOI) and Geodetic Facility for the Advancement of Geoscience (GAGE), to identify typical user access patterns and to develop a model that can be used for data pre-fetching. Furthermore, we evaluate our data pre-fetching model and the proposed framework using a simulation of the Virtual Data Collaboratory (VDC) platform that provides in-network data staging and processing capabilities. The results demonstrate that the ability of the framework to significantly improve data delivery performance and reduce network traffic at the observatories{\textquoteright} facilities.}, keywords = {Cyberinfrastructure, Data pre-fetching, Distributed data sharing, Distributed facilities, Observatories, Virtual Data Collaboratory}, doi = {10.1016/j.future.2021.03.004}, url = {https://app.dimensions.ai/details/publication/pub.1136656679}, author = {Qin, Yubo and Rodero, Ivan and Simonet, Anthony and Meertens, Charles and Reiner, Daniel and Riley, James and Parashar, Manish} } @article {RN250, title = {Long-term noise interferometry analysis in the northeast Pacific Ocean}, journal = {The Journal of the Acoustical Society of America}, volume = {149}, number = {4}, year = {2021}, pages = {a90-a90}, type = {Journal Article}, doi = {10.1121/10.0004609}, url = {https://app.dimensions.ai/details/publication/pub.1138547479}, author = {Ragland, John and Abadi, Shima} } @article {RN272, title = {Mesoscale and Submesoscale Shelf-Ocean Exchanges Initialize an Advective Marine Heatwave}, journal = {Journal of Geophysical Research - Oceans}, year = {2021}, type = {Journal Article}, doi = {10.1029/2021jc017927}, url = {https://app.dimensions.ai/details/publication/pub.1143744195}, author = {Chen, Ke and Gawarkiewicz, Glen and Yang, Jiayan} } @article {RN265, title = {Monitoring fin whale calls using Ocean Observatories Initiative Regional Cabled Array}, journal = {The Journal of the Acoustical Society of America}, volume = {150}, number = {4}, year = {2021}, pages = {a83-a83}, type = {Journal Article}, doi = {10.1121/10.0007704}, url = {https://app.dimensions.ai/details/publication/pub.1142679681}, author = {Wang, Xuyang and Hilmo, Rose and Wilcock, William S. and Gonzalez, Kathleen and Borras, Mouffee} } @article {RN211, title = {More than skin deep: sea surface temperature as a means of inferring Atlantic Water variability on the southeast Greenland continental shelf near Helheim Glacier}, journal = {Journal of Geophysical Research - Oceans}, year = {2021}, type = {Journal Article}, abstract = {Outlet glaciers account for almost half of the Greenland Ice Sheet{\textquoteright}s mass loss since 1990. Warming subsurface Atlantic Water (AW) has been implicated in much of that loss, particularly along Greenland{\textquoteright}s southeastern coast. However, oceanographic observations are sparse prior to the last decade, making it difficult to diagnose changes in AW properties reaching the glaciers. Here, we investigate the use of sea surface temperatures (SST) to quantify ocean temperature variability on the continental shelf near Sermilik Fjord and Helheim Glacier. We find that after removing the short-term, atmospheric-driven variability in non-winter months, regional SSTs provide a reliable upper ocean temperature record. In the trough region near Sermilik Fjord, the adjusted SSTs correlate well with moored ocean measurements of the water entering the fjord at depth and driving glacier melting. Using this relationship, we reconstruct the AW variability on the shelf dating back to 2000, eight years before the first mooring deployments. Seasonally, AW reaches close to the fjord{\textquoteright}s mouth in fall and winter and further offshore in spring. Interannually, the AW temperatures in the trough do not always track properties in the source waters of the Irminger Current. Instead, the properties of the waters found at the fjord mouth depend on both variations in the source AW and, also, in the Polar Water that flows into the region from the Arctic Ocean. Satellite-derived SSTs, although dependent on local oceanography, have the potential to improve understanding around previously unanswered glacier-ocean questions in areas surrounding Greenland and Antarctica.}, doi = {10.1029/2020jc016509}, url = {https://app.dimensions.ai/details/publication/pub.1136983754}, author = {Snow, T. and Straneo, F. and Holte, J. and Grigsby, S. and Abdalati, W. and Scambos, T.} } @article {RN240, title = {A new era of digitalisation for ocean sustainability?}, journal = {OECD Science, Technology and Industry Policy Papers}, year = {2021}, type = {Journal Article}, abstract = {As the United Nations Decade on Ocean Science for Sustainable Development begins, this paper explores recent and likely future digital technologies - especially in the field of ocean observation - that will contribute to ocean sustainability. It examines advances that could lead to substantial improvements in the data collection and analysis of the impact of climate change and human activity on marine ecosystems, while also contributing to the monitoring and reduction of the ecological footprint of ocean-related economic activity. The paper also provides preliminary reflections on how the COVID-19 pandemic might affect digitalisation in the ocean economy, and what strategies could help support ocean research and innovation during and after the crisis.}, doi = {10.1787/a4734a65-en}, url = {https://app.dimensions.ai/details/publication/pub.1137801627}, author = {Stevens, Barrie and Jolly, Claire and Jolliffe, James} } @article {RN195, title = {Observation impacts on the Mid-Atlantic Bight front and cross-shelf transport in 4D-Var ocean state estimates: Part II {\textemdash} The Pioneer Array}, journal = {Ocean Modelling}, volume = {157}, year = {2021}, pages = {101731}, type = {Journal Article}, abstract = {The Regional Ocean Modeling System (ROMS) 4-dimensional variational (4D-Var) data assimilation system was used to compute ocean state estimates of the Mid-Atlantic Bight (MAB). A three-level nested grid configuration was employed with horizontal resolution successively enhanced from 7 km down to 800 m at the innermost nest. This captures the dynamics on space- and time-scales ranging from the Gulf Stream western boundary current down to the rapidly evolving and energetic sub-mesoscale circulation. This is a companion study to Levin et al. (2020) which examined the overall impacts of the entire observing system on shelf-break exchange. This follow-on study specifically focuseson the impact of the in situ elements of the ocean observing system on the 4D-Var analyses. The particular focus here is on the Pioneer Array, a high-density observing system in the MAB designed to measure the multi-scale nature of shelf-break exchange processes. Building on Levin et al. (2020), it is found that the relative impact of observations from different components of the Pioneer Array depends on the scales of motion that are resolved by each nested grid. This is in apparent agreement with the linear theory of geostrophic adjustment despite the O(1) Rossby number. The synergy between the observations from different observing platforms has also been quantified by comparing the observation impacts with the sensitivity of the 4D-Var analyses to changes in the observing array. It is found that while some observations do not have a significant direct impact on the analyses, they nevertheless provide essential information about the presence of circulation features, corroborating that measured by other sensors. Thus, the individual parts of the observing system can borrow strength from each other. Finally, the contribution of each component of the observing system to the expected error in the 4D-Var analyses was also quantified, where the critical role played by the Pioneer Array moorings in resolving the sub-mesoscale circulation is again highlighted.}, keywords = {Mid-Atlantic Bight, Observation impact, Observation sensitivity, Pioneer Array, ROMS 4D-Var}, doi = {10.1016/j.ocemod.2020.101731}, url = {https://app.dimensions.ai/details/publication/pub.1132944594}, author = {Levin, Julia and Arango, Hernan G. and Laughlin, Bruce and Hunter, Elias and Wilkin, John and Moore, Andrew M.} } @article {RN291, title = {Observation-based estimates of heat and freshwater exchanges from the subtropical North Atlantic to the Arctic}, journal = {Progress In Oceanography}, volume = {197}, year = {2021}, pages = {102640}, type = {Journal Article}, doi = {10.1016/j.pocean.2021.102640}, url = {https://app.dimensions.ai/details/publication/pub.1139426977 https://doi.org/10.1016/j.pocean.2021.102640}, author = {Li, Feili and Lozier, M. Susan and Holliday, N. Penny and Johns, William E. and Le Bras, Isabela A. and Moat, Ben I. and Cunningham, Stuart A. and de Jong, M. Femke} } @article {RN213, title = {Observations of Shallow Methane Bubble Emissions From Cascadia Margin}, journal = {Frontiers in Earth Science}, volume = {9}, year = {2021}, pages = {613234}, type = {Journal Article}, abstract = {Open questions exist about whether methane emitted from active seafloor seeps reaches the surface ocean to be subsequently ventilated to the atmosphere. Water depth variability, coupled with the transient nature of methane bubble plumes, adds complexity to examining these questions. Little data exist which trace methane transport from release at a seep into the water column. Here, we demonstrate a coupled technological approach for examining methane transport, combining multibeam sonar, a field-portable laser-based spectrometer, and the ChemYak, a robotic surface kayak, at two shallow (<75 m depth) seep sites on the Cascadia Margin. We demonstrate the presence of elevated methane (above the methane equilibration concentration with the atmosphere) throughout the water column. We observe areas of elevated dissolved methane at the surface, suggesting that at these shallow seep sites, methane is reaching the air-sea interface and is being emitted to the atmosphere.}, keywords = {bubbles, Cascadia Margin, laser spectrometer, methane, multibeam sonar, ocean sensing, seeps, surface vehicle}, doi = {10.3389/feart.2021.613234}, url = {https://app.dimensions.ai/details/publication/pub.1137604010 https://www.frontiersin.org/articles/10.3389/feart.2021.613234/pdf}, author = {Michel, Anna P. M. and Preston, Victoria L. and Fauria, Kristen E. and Nicholson, David P.} } @article {RN266, title = {OOIPy: A Python toolbox for accessing and analyzing sata from the Ocean Observatories Initiative}, journal = {The Journal of the Acoustical Society of America}, volume = {150}, number = {4}, year = {2021}, pages = {a123-a123}, type = {Journal Article}, doi = {10.1121/10.0007845}, url = {https://app.dimensions.ai/details/publication/pub.1142685236}, author = {Schwock, Felix and Ragland, John and Abadi, Shima} } @article {RN277, title = {An outsized role for the Labrador Sea in the multidecadal variability of the Atlantic overturning circulation}, journal = {Science Advances}, volume = {7}, number = {41}, year = {2021}, pages = {eabh3592}, type = {Journal Article}, doi = {10.1126/sciadv.abh3592}, url = {https://app.dimensions.ai/details/publication/pub.1141690675 https://www.science.org/doi/pdf/10.1126/sciadv.abh3592?download=true}, author = {Yeager, Stephen and Castruccio, Fred and Chang, Ping and Danabasoglu, Gokhan and Maroon, Elizabeth and Small, Justin and Wang, Hong and Wu, Lixin and Zhang, Shaoqing} } @article {RN269, title = {Perspectives on Marine Data Science as a Blueprint for Emerging Data Science Disciplines}, journal = {Frontiers in Marine Science}, volume = {8}, year = {2021}, pages = {678404}, type = {Journal Article}, doi = {10.3389/fmars.2021.678404}, url = {https://app.dimensions.ai/details/publication/pub.1143539440 https://www.frontiersin.org/articles/10.3389/fmars.2021.678404/pdf}, author = {Verwega, Maria-Theresia and Trahms, Carola and Antia, Avan N. and Dickhaus, Thorsten and Prigge, Enno and Prinzler, Martin H. U. and Renz, Matthias and Schartau, Markus and Slawig, Thomas and Somes, Christopher J. and Biastoch, Arne} } @article {RN257, title = {The PLUM Earthquake Early Warning Algorithm: A Retrospective Case Study of West Coast, USA, Data}, journal = {Journal of Geophysical Research: Solid Earth}, volume = {126}, number = {7}, year = {2021}, type = {Journal Article}, doi = {10.1029/2020jb021053}, url = {https://app.dimensions.ai/details/publication/pub.1138776791 https://authors.library.caltech.edu/109556/10/2020JB021053.pdf}, author = {Kilb, D. and Bunn, J. J. and Saunders, J. K. and Cochran, E. S. and Minson, S. E. and Baltay, A. and O{\textquoteright}Rourke, C. T. and Hoshiba, M. and Kodera, Y.} } @article {RN286, title = {Rapid Freshening of Iceland Scotland Overflow Water Driven by Entrainment of a Major Upper Ocean Salinity Anomaly}, journal = {Geophysical Research Letters}, volume = {48}, number = {22}, year = {2021}, type = {Journal Article}, doi = {10.1029/2021gl094396}, url = {https://app.dimensions.ai/details/publication/pub.1142734619}, author = {Devana, Manish S. and Johns, William E. and Houk, Adam and Zou, Sijia} } @article {RN200, title = {A regional, early spring bloom of Phaeocystis pouchetii on the New England continental shelf}, journal = {Journal of Geophysical Research - Oceans}, year = {2021}, type = {Journal Article}, abstract = {The genus Phaeocystis is distributed globally and has considerable ecological, biogeochemical, and societal impacts. Understanding its distribution, growth and ecological impacts has been limited by lack of extensive observations on appropriate scales. In 2018, we investigated the biological dynamics of the New England continental shelf and encountered a substantial bloom of Phaeocystis pouchetii. Based on satellite imagery during January through April, the bloom extended over broad expanses of the shelf; furthermore, our observations demonstrated that it reached high biomass levels, with maximum chlorophyll concentrations exceeding 16 {\textmu}g L-1 and particulate organic carbon levels > 95 {\textmu}mol L-1. Initially, the bloom was largely confined to waters with temperatures <6{\textdegree}C, which in turn were mostly restricted to shallow areas near the coast. As the bloom progressed, it appeared to sink into the bottom boundary layer; however, enough light and nutrients were available for growth. The bloom was highly productive (net community production integrated through the mixed layer from stations within the bloom averaged 1.16 g C m-2 d-1) and reduced nutrient concentrations considerably. Long-term coastal observations suggest that Phaeocystis blooms occur sporadically in spring on Nantucket Shoals and presumably expand onto the continental shelf. Based on the distribution of Phaeocystis during our study, we suggest that it can have a significant impact on the overall productivity and ecology of the New England shelf during the winter/spring transition.}, doi = {10.1029/2020jc016856}, url = {https://app.dimensions.ai/details/publication/pub.1134619519}, author = {Smith, Walker O. and Zhang, Weifeng and Hirzel, Andrew and Stanley, Rachel M. and Meyer, Meredith G. and Sosik, Heidi and Alatalo, Philip and Oliver, Hilde and Sandwith, Zoe and Crockford, Taylor and Peacock, Emily E. and Mehta, Arshia and McGillicuddy, Dennis J.} } @article {RN248, title = {Relationship between ocean ecosystem indicators and year class strength of the invasive European green crab (Carcinus maenas)}, journal = {Progress in Oceanography}, volume = {196}, year = {2021}, type = {Journal Article}, issn = {0079-6611}, doi = {10.1016/j.pocean.2021.102618}, author = {Yamada, S. B. and Fisher, J. L. and Kosro, P. M.} } @article {RN239, title = {A review of 20 years (1999{\textendash}2019) of Turkish{\textendash}French collaboration in marine geoscience research in the Sea of Marmara}, journal = {Mediterranean Geoscience Reviews}, volume = {3}, number = {1}, year = {2021}, pages = {3-27}, type = {Journal Article}, abstract = {This paper retraces the history and main achievements of the ongoing Turkish{\textendash}French collaboration in marine geoscience research in the Sea of Marmara, which was initiated in the aftermath of the 1999, Izmit and Duzce earthquakes. The collaboration resulted in nine large oceanographic cruises along with six recovery operations involving diverse vessels, and in the participation in two major EU-funded programmes (ESONET-NoE and MARSITE) and to one bilateral project, e.g. the MAREGAMI Project, co-funded by TUBITAK and ANR (the Turkish and French national funding agencies for research, respectively). In this paper, we review the major scientific contributions on the tectonic evolution of the North-Anatolian Fault in the Marmara Region; on the relationships between faulting, seismicity, fluids and ecosystems; and on paleo-seismology and paleo-oceanography in the Sea of Marmara.}, doi = {10.1007/s42990-021-00055-8}, url = {https://app.dimensions.ai/details/publication/pub.1137743967}, author = {G{\'e}li, Louis and Henry, Pierre and {\c C}a{\u g}atay, M. Namik} } @article {RN202, title = {A Review of Holography in the Aquatic Sciences: In situ Characterization of Particles, Plankton, and Small Scale Biophysical Interactions}, journal = {Frontiers in Marine Science}, volume = {7}, year = {2021}, pages = {572147}, type = {Journal Article}, abstract = {The characterization of particle and plankton populations, as well as microscale biophysical interactions, is critical to several important research areas in oceanography and limnology. A growing number of aquatic researchers are turning to holography as a tool of choice to quantify particle fields in diverse environments, including but not limited to, studies on particle orientation, thin layers, phytoplankton blooms, and zooplankton distributions and behavior. Holography provides a non-intrusive, free-stream approach to imaging and characterizing aquatic particles, organisms, and behavior in situ at high resolution through a 3-D sampling volume. Compared to other imaging techniques, e.g., flow cytometry, much larger volumes of water can be processed over the same duration, resolving particle sizes ranging from a few microns to a few centimeters. Modern holographic imaging systems are compact enough to be deployed through various modes, including profiling/towed platforms, buoys, gliders, long-term observatories, or benthic landers. Limitations of the technique include the data-intensive hologram acquisition process, computationally expensive image reconstruction, and coherent noise associated with the holograms that can make post-processing challenging. However, continued processing refinements, rapid advancements in computing power, and development of powerful machine learning algorithms for particle/organism classification are paving the way for holography to be used ubiquitously across different disciplines in the aquatic sciences. This review aims to provide a comprehensive overview of holography in the context of aquatic studies, including historical developments, prior research applications, as well as advantages and limitations of the technique. Ongoing technological developments that can facilitate larger employment of this technique toward in situ measurements in the future, as well as potential applications in emerging research areas in the aquatic sciences are also discussed.}, keywords = {biophysical interactions, holography, particle interactions, particle patchiness, plankton distributions, plankton imaging, underwater imaging}, doi = {10.3389/fmars.2020.572147}, url = {https://app.dimensions.ai/details/publication/pub.1134785939 https://www.frontiersin.org/articles/10.3389/fmars.2020.572147/pdf}, author = {Nayak, Aditya R. and Malkiel, Ed and McFarland, Malcolm N. and Twardowski, Michael S. and Sullivan, James M.} } @article {RN290, title = {Role of air{\textendash}sea fluxes and ocean surface density in the production of deep waters in the eastern subpolar gyre of the North Atlantic}, journal = {Ocean Science}, volume = {17}, number = {5}, year = {2021}, pages = {1353-1365}, type = {Journal Article}, doi = {10.5194/os-17-1353-2021}, url = {https://app.dimensions.ai/details/publication/pub.1141645433 https://os.copernicus.org/articles/17/1353/2021/os-17-1353-2021.pdf}, author = {Petit, Tillys and Lozier, M. Susan and Josey, Simon A. and Cunningham, Stuart A.} } @article {RN262, title = {Role of Deep-Sea Equipment in Promoting the Forefront of Studies on Life in extreme environments}, journal = {iScience}, year = {2021}, pages = {103299}, type = {Journal Article}, doi = {10.1016/j.isci.2021.103299}, url = {https://app.dimensions.ai/details/publication/pub.1141939143}, author = {Liang, Jianzhen and Feng, Jing-Chun and Zhang, Si and Cai, Yanpeng and Yang, Zhifeng and Ni, Tian and Yang, Hua-Yong} } @article {RN267, title = {Satellite Remote Sensing and the Marine Biodiversity Observation Network: Current Science and Future Steps}, journal = {Oceanography}, volume = {34}, number = {2}, year = {2021}, type = {Journal Article}, doi = {10.5670/oceanog.2021.215}, url = {https://app.dimensions.ai/details/publication/pub.1142458909 https://tos.org/oceanography/assets/docs/34-2_kavanaugh.pdf}, author = {Kavanaugh, Maria and University, Oregon State and Bell, Tom and Catlett, Dylan and Cimino, Megan and Doney, Scott and Klajbor, Willem and Messi{\'e}, Monique and Montes, Enrique and Karger, Frank Muller and Otis, Daniel and Santora, Jarrod and Schroeder, Isaac and Tri{\~n}anes, Joaquin and Siegel, David} } @article {RN210, title = {Seafloor Geodetic Pressure Measurements to Detect Shallow Slow Slip Events: Methods to Remove Contributions from Ocean Water}, journal = {Journal of Geophysical Research: Solid Earth}, year = {2021}, type = {Journal Article}, abstract = {Shallow slow slip events (SSEs) provide a mechanism for strain release in the shallow part of subduction zones, with fundamental implications for fault mechanics and tsunami hazards. Despite their importance, SSEs are challenging to monitor. They occur under the ocean far from land-based GPS stations, and while seafloor pressure sensors can detect SSE vertical seafloor movements, the measured bottom pressure includes {\textquotedblleft}ocean noise{\textquotedblright} signals from pressure variations within the water column. Seeking to improve techniques to remove ocean noise, a pilot study offshore Oregon collected seafloor pressure and near-bottom current measurements at four sites from April to November 2017. Three methods were applied to reduce ocean noise: 1) subtract a reference pressure, 2) apply complex empirical orthogonal function analysis to pressure measurements, and 3) combine pressure and current measurements with optimal interpolation (OI). All three methods are established techniques from either geodesy or oceanography. Each method produced residual standard deviation, σ < 1 hPa. No SSE was detected during this study. For illustration purposes synthetic SSEs of 2 cm amplitude and 7-days duration were added and detected, one at a time at different spots. Because currents are unaffected by a SSE, the combination of currents and pressures with the dynamical constraint of geostrophy in OI reduced the false interpretation of the synthetic SSEs as oceanic. OI produced the most reliable detection. Future seafloor geodesy field projects should consider adding current sensors and using OI methods to reduce ocean noise and to reveal tectonic signals.}, doi = {10.1029/2020jb020065}, url = {https://app.dimensions.ai/details/publication/pub.1136480068}, author = {Watts, D. Randolph and Wei, Meng and Tracey, Karen L. and Donohue, Kathleen A. and He, Bing} } @article {RN294, title = {Seasonal and Interannual Variability of the Meridional Overturning Circulation in the Subpolar North Atlantic Diagnosed From a High Resolution Reanalysis Data Set}, journal = {Journal of Geophysical Research - Oceans}, volume = {126}, number = {6}, year = {2021}, type = {Journal Article}, doi = {10.1029/2020jc017130}, url = {https://app.dimensions.ai/details/publication/pub.1138265906}, author = {Wang, Hanshi and Zhao, Jian and Li, Feili and Lin, Xiaopei} } @article {RN292, title = {Seasonal Cycle of the Coastal West Greenland Current System Between Cape Farewell and Cape Desolation From a Very High-Resolution Numerical Model}, journal = {Journal of Geophysical Research - Oceans}, volume = {126}, number = {5}, year = {2021}, type = {Journal Article}, doi = {10.1029/2020jc017017}, url = {https://app.dimensions.ai/details/publication/pub.1137801235}, author = {Gou, Ruijian and Feucher, Charl{\`e}ne and Pennelly, Clark and Myers, Paul G.} } @article {RN209, title = {The Seismo-acoustics of Submarine Volcanic Eruptions}, journal = {Journal of Geophysical Research: Solid Earth}, year = {2021}, type = {Journal Article}, abstract = {Many of the world{\textquoteright}s volcanoes are hidden beneath the ocean{\textquoteright}s surface where eruptions are difficult to observe. However, seismo-acoustic signals produced by these eruptions provide a useful means of identifying active submarine volcanism. A literature survey revealed reports of 119 seismo-acoustically recorded submarine eruptions since 1939. Submarine eruptions have been recorded in all major tectonic settings, with a range of geochemistries, and at a variety of water depths, but the reports are dominated by eruptions in the Pacific and at only a few locations. Many of the reports offer little detail, with over half of the observations made from distances >500 km, and only about half were confirmed as eruptions by non-seismo-acoustic evidence. The reported seismo-acoustic signals cover a wide variety of processes, including earthquakes, explosions, various types of tremor, signals related to lava extrusion, and landslides. Recorded signals can sometimes be difficult to classify or confidently associate with an eruption, although there has been progress in this regard. Real-time monitoring of submarine eruptions has been on-going for several decades on regional and global scales with growing interest and effort in local networks. Real-time networks are complemented by short-term instrument deployments that often give more detailed insights into the dynamics and processes of submarine eruptions. Thorough seismo-acoustic monitoring and study has increased our understanding of submarine eruptions, especially of deep-sea volcanoes and spreading centers. Despite this, there are still many outstanding questions that need to be addressed for submarine volcanoes to be as well understood and monitored as their terrestrial counterparts.}, doi = {10.1029/2020jb020912}, url = {https://app.dimensions.ai/details/publication/pub.1136472734}, author = {Tepp, Gabrielle and Dziak, Robert P.} } @article {RN270, title = {Statistical analysis and modeling of underwater wind noise at the northeast pacific continental margin}, journal = {The Journal of the Acoustical Society of America}, volume = {150}, number = {6}, year = {2021}, pages = {4166-4177}, type = {Journal Article}, doi = {10.1121/10.0007463}, url = {https://app.dimensions.ai/details/publication/pub.1143712938 https://asa.scitation.org/doi/pdf/10.1121/10.0007463}, author = {Schwock, Felix and Abadi, Shima} } @article {RN246, title = {Subpolar North Atlantic western boundary density anomalies and the Meridional Overturning Circulation}, journal = {Nature Communications}, volume = {12}, number = {1}, year = {2021}, pages = {3002}, type = {Journal Article}, abstract = {Changes in the Atlantic Meridional Overturning Circulation, which have the potential to drive societally-important climate impacts, have traditionally been linked to the strength of deep water formation in the subpolar North Atlantic. Yet there is neither clear observational evidence nor agreement among models about how changes in deep water formation influence overturning. Here, we use data from a trans-basin mooring array (OSNAP{\textemdash}Overturning in the Subpolar North Atlantic Program) to show that winter convection during 2014{\textendash}2018 in the interior basin had minimal impact on density changes in the deep western boundary currents in the subpolar basins. Contrary to previous modeling studies, we find no discernable relationship between western boundary changes and subpolar overturning variability over the observational time scales. Our results require a reconsideration of the notion of deep western boundary changes representing overturning characteristics, with implications for constraining the source of overturning variability within and downstream of the subpolar region.}, doi = {10.1038/s41467-021-23350-2}, url = {https://app.dimensions.ai/details/publication/pub.1138293382 https://www.nature.com/articles/s41467-021-23350-2.pdf}, author = {Li, F. and Lozier, M. S. and Bacon, S. and Bower, A. S. and Cunningham, S. A. and de Jong, M. F. and deYoung, B. and Fraser, N. and Fried, N. and Han, G. and Holliday, N. P. and Holte, J. and Houpert, L. and Inall, M. E. and Johns, W. E. and Jones, S. and Johnson, C. and Karstensen, J. and Le Bras, I. A. and Lherminier, P. and Lin, X. and Mercier, H. and Oltmanns, M. and Pacini, A. and Petit, T. and Pickart, R. S. and Rayner, D. and Straneo, F. and Thierry, V. and Visbeck, M. and Yashayaev, I. and Zhou, C.} } @article {RN251, title = {Tidal triggering of micro-seismicity associated with caldera dynamics in the Juan de Fuca ridge}, journal = {Journal of Volcanology and Geothermal Research}, volume = {417}, year = {2021}, pages = {107319}, type = {Journal Article}, doi = {10.1016/j.jvolgeores.2021.107319}, url = {https://app.dimensions.ai/details/publication/pub.1138891969}, author = {Sahoo, Sambit and Senapati, Batakrushna and Panda, Dibyashakti and Tiwari, Deepak Kumar and Santosh, M. and Kundu, Bhaskar} } @article {RN258, title = {Tracking Microbial Evolution in the Subseafloor Biosphere}, journal = {mSystems}, volume = {6}, number = {4}, year = {2021}, pages = {e00731-21}, type = {Journal Article}, doi = {10.1128/msystems.00731-21}, url = {https://app.dimensions.ai/details/publication/pub.1140464244 https://doi.org/10.1128/msystems.00731-21}, author = {Anderson, Rika E.} } @article {RN252, title = {Trends in low frequency ambient noise for a site 80 km off the Oregon coast over approximately four years ending August 2020}, journal = {The Journal of the Acoustical Society of America}, volume = {149}, number = {4}, year = {2021}, pages = {a87-a87}, type = {Journal Article}, doi = {10.1121/10.0004599}, url = {https://app.dimensions.ai/details/publication/pub.1138547469}, author = {Dahl, Peter H. and Harrington, Michael and Dall{\textquoteright}Osto, David R.} } @article {RN243, title = {Trends in low-frequency underwater noise off the Oregon coast and impacts of COVID-19 pandemica)}, journal = {Journal of the Acoustical Society of America}, volume = {149}, number = {6}, year = {2021}, pages = {4073-4077}, type = {Journal Article}, abstract = {Approximately six years of underwater noise data recorded from the Regional Cabled Array network are examined to study long-term trends. The data originate from station HYS14 located 87 km offshore of Newport, OR. The results indicate that the third-octave band level centered at 63 Hz and attributable to shipping activity is reduced in the spring of 2020 by about 1.6 dB relative to the mean of the prior five years, owing to the reduced economic activity initiated by the COVID-19 pandemic. The results are subtle, as the noise reduction is less than the typical seasonal fluctuation associated with warming ocean surface temperatures in the summer that reduces mode excitation support at typical ship source depths, causing a repeated annual level change on the order of 4 dB at shipping frequencies. Seasonality of the noise contribution near 20 Hz from fin whales is also discussed. Corroboration of a COVID-19 effect on shipping noise is offered by an analysis of automatic identification system shipping data and shipping container activity for Puget Sound, over the same six-year period, which shows a reduction in the second quarter of 2020 by \~{}19\% and \~{}17\%, respectively, relative to the mean of the prior five years. }, issn = {0001-4966}, doi = {10.1121/10.0005192}, author = {Dahl, P. H. and Dall{\textquoteright}Osto, D. R. and Harrington, M. J.} } @article {RN260, title = {Understanding physical drivers of the 2015/16 marine heatwaves in the Northwest Atlantic}, journal = {Scientific Reports}, volume = {11}, number = {1}, year = {2021}, pages = {17623}, type = {Journal Article}, issn = {2045-2322}, doi = {10.1038/s41598-021-97012-0}, url = {https://doi.org/10.1038/s41598-021-97012-0}, author = {Perez, E. and Ryan, S. and Andres, M. and Gawarkiewicz, G. and Ummenhofer, C. C. and Bane, J. and Haines, S.} } @article {RN261, title = {Variability of Natural Methane Bubble Release at Southern Hydrate Ridge}, journal = {Geochemistry Geophysics Geosystems}, year = {2021}, type = {Journal Article}, doi = {10.1029/2021gc009894}, url = {https://app.dimensions.ai/details/publication/pub.1141266962}, author = {Marcon, Yann and Kelley, Deborah and Thornton, Blair and Manalang, Dana and Bohrmann, Gerhard} } @article {RN207, title = {Wind, waves, and surface currents in the Southern Ocean: observations from the Antarctic Circumnavigation Expedition}, journal = {Earth System Science Data}, volume = {13}, number = {3}, year = {2021}, pages = {1189-1209}, type = {Journal Article}, abstract = { The Southern Ocean has a profound impact on the Earth{\textquoteright}s climate system. Its strong winds, intense currents, and fierce waves are critical components of the air{\textendash}sea interface and contribute to absorbing, storing, and releasing heat, moisture, gases, and momentum. Owing to its remoteness and harsh environment, this region is significantly undersampled, hampering the validation of prediction models and large-scale observations from satellite sensors. Here, an unprecedented data set of simultaneous observations of winds, surface currents, and ocean waves is presented, to address the scarcity of in situ observations in the region {\textendash} https://doi.org/10.26179/5ed0a30aaf764 (Alberello et al., 2020c) and https://doi.org/10.26179/5e9d038c396f2 (Derkani et al., 2020). Records were acquired underway during the Antarctic Circumnavigation Expedition (ACE), which went around the Southern Ocean from December 2016 to March 2017 (Austral summer). Observations were obtained with the wave and surface current monitoring system WaMoS-II, which scanned the ocean surface around the vessel using marine radars. Measurements were assessed for quality control and compared against available satellite observations. The data set is the most extensive and comprehensive collection of observations of surface processes for the Southern Ocean and is intended to underpin improvements of wave prediction models around Antarctica and research of air{\textendash}sea interaction processes, including gas exchange and dynamics of sea spray aerosol particles. The data set has further potentials to support theoretical and numerical research on lower atmosphere, air{\textendash}sea interface, and upper-ocean processes.}, doi = {10.5194/essd-13-1189-2021}, url = {https://app.dimensions.ai/details/publication/pub.1136590412 https://essd.copernicus.org/articles/13/1189/2021/essd-13-1189-2021.pdf}, author = {Derkani, Marzieh H. and Alberello, Alberto and Nelli, Filippo and Bennetts, Luke G. and Hessner, Katrin G. and MacHutchon, Keith and Reichert, Konny and Aouf, Lotfi and Khan, Salman and Toffoli, Alessandro} } @article {RN197, title = {Wintertime particulate organic matter distributions in surface waters of the northern California current system}, journal = {Continental Shelf Research}, volume = {213}, year = {2021}, pages = {104312}, type = {Journal Article}, abstract = {Semi-automated sampling via the surface underway systems of research vessels was used to explore the distribution and composition of particulate organic matter in surface waters of the northern California Current ecosystem during winter, a poorly studied period that is characterized by downwelling favorable winds and elevated discharge by coastal rivers. New wintertime observations were compared to those measured during a summer cruise characterized by strong upwelling and highly reduced coastal river flows. Particulate organic carbon (POC) concentrations in surface waters along the Oregon shelf during winter periods were significantly lower (7.0 {\textpm} 5.0 μM) than those measured in the same region during summer (21 {\textpm} 25 μM) with similar seasonal contrasts in chlorophyll (Chl) concentrations (1.7 {\textpm} 1.7 mg Chl m-3 in winter and 8.7 {\textpm} 3.8 mg Chl m-3 in summer). The combination of POC, Chl, and particle beam attenuation (cp) measurements revealed spatial and temporal distributions that confirm the importance of physical drivers such as wind, waves and river discharge in influencing the biogeochemistry of eastern boundary current systems during non-upwelling conditions. Elevated contributions of allocthonous particulate materials with distinct compositional characteristics, including low Chl:POC and POC:cp ratios, were measured during winter in low-density, low-salinity surface waters influenced by coastal river discharge. In contrast, mid-salinity, intermediate-density surface waters exhibited higher concentrations of POM with elevated Chl:POC and POC:cp ratios, which approached those measured during highly productive summer upwelling periods. These results are solid evidence for wintertime phytoplankton productivity along this margin under elevated buoyancy and nutrient contributions from the discharge of coastal rivers.}, keywords = {California current, Oregon margin, Particulate organic matter}, doi = {10.1016/j.csr.2020.104312}, url = {https://app.dimensions.ai/details/publication/pub.1132922324}, author = {Go{\~n}i, Miguel A. and Welch, Kylie A. and Alegria, Emmanuel and Alleau, Yvan and Watkins-Brandt, Katie and White, Angelicque E.} } @article {RN192, title = {Acoustic and In-situ Observations of Deep Seafloor Hydrothermal Discharge: an OOI Cabled Array ASHES Vent Field Case Study}, journal = {Earth and Space Science}, year = {2020}, type = {Journal Article}, abstract = {The Cabled Observatory Vent Imaging Sonar (COVIS) was installed on the Ocean Observatories Initiative{\textquoteright}s Regional Cabled Array observatory at ASHES hydrothermal vent field on Axial Seamount in July 2018. The acoustic backscatter data recorded by COVIS in August{\textendash}September 2018, in conjunction with in situ temperature measurements, are used to showcase and verify the use of COVIS for long-term, quantitative monitoring of hydrothermal discharge. Specifically, sonar data processing generates three-dimensional backscatter images of the buoyant plumes above major sulfide structures and two-dimensional maps of diffuse flows within COVIS{\textquoteright}s field-of-view. The backscatter images show substantial changes of plume appearance and orientation that mostly reflect plume bending in the presence of ambient currents and potentially the variations of outflow fluxes. The intensity of acoustic backscatter decreases significantly for highly bent plumes as compared to nearly vertical plumes, reflecting enhanced mixing of plume fluids with seawater driven by ambient currents. A forward model of acoustic backscatter from a buoyancy-driven plume developed in this study yields a reasonable match with the observation, which paves the way for inversely estimating the source heat flux of a hydrothermal plume from acoustic backscatter measurements. The acoustic observations of diffuse flows show large temporal variations on time scales of hours to days, especially at tidal frequencies, but no apparent long-term trend. These findings demonstrate COVIS{\textquoteright}s ability to quantitatively monitor hydrothermal discharge from both focused and diffuse sources to provide the research community with key observational data for studying the linkage of hydrothermal activity with oceanic and geological processes.}, keywords = {acoustic, axial seamount, hydrothermal, imaging, observatory, sonar}, doi = {10.1029/2020ea001269}, url = {https://app.dimensions.ai/details/publication/pub.1133310442}, author = {Xu, Guangyu and Bemis, Karen and Jackson, Darrell and Ivakin, Anatoliy} } @article {RN278, title = {Atlantic Deep Water Formation Occurs Primarily in the Iceland Basin and Irminger Sea by Local Buoyancy Forcing}, journal = {Geophysical Research Letters}, volume = {47}, number = {22}, year = {2020}, type = {Journal Article}, doi = {10.1029/2020gl091028}, url = {https://app.dimensions.ai/details/publication/pub.1132581129 http://nora.nerc.ac.uk/id/eprint/529098/1/2020GL091028.pdf}, author = {Petit, Tillys and Lozier, M. Susan and Josey, Simon A. and Cunningham, Stuart A.} } @article {RN182, title = {Building the integrated observational network of {\textquotedblleft}Transparent Ocean{\textquotedblright}}, journal = {Chinese Science Bulletin (Chinese Version)}, volume = {65}, number = {25}, year = {2020}, pages = {2654-2661}, type = {Journal Article}, abstract = {We live in an exciting era for ocean science, particularly when compared to three decades ago when the ocean was vastly underexplored. Progress can only be made through discovery, observation, understanding of the ocean from the surface to the deep sea, from global to local processes, and from physics, biogeochemistry to ecology. Ocean observation is the basis of oceanic scientific research and is a key to global competition in marine science and technology. Breakthroughs depend on innovation in marine observation and exploration technology. Based on the current frontier issues of ocean science, we report ways to build a three-dimensional observation network of {\textquotedblleft}Transparent Ocean{\textquotedblright}. The network will effectively promote China{\textquoteright}s construction of an international collaborative innovation network for marine science. The three-dimensional observation network {\textquotedblleft}Transparent Ocean{\textquotedblright} focuses on building an intelligent mobile platform and integrates satellites, fixed platforms, vessel network, and submarine observation systems to make the oceans truly transparent. This network includes four sub-programs. (1) An Ocean Star Cluster Program, which resolves ocean variability at sub-meso and sub-week scales with a centimeter-level accuracy, to partially reveal the marine life system and ecosystem with a 10-m vertical interval in the euphotic layer, moving a significant step forward towards a {\textquotedblleft}Transparent Ocean{\textquotedblright} down to the vicinity of thermocline both dynamically and bio-optically. (2) An Air-Sea Interface Program, which aims to build an observational network that integrates fixed and mobile platforms to achieve a three-dimensional view of key elements/variables of the air-sea interface. (3) A Starry Deep Sea Program, which builds a deep sea observation system with deep Argo, deep gliders, deep-sea autonomous underwater vehicles (AUVs), intelligent buoys, and other facilities. The system will provide support for information procurement through deep sea navigation and positioning technology. (4) An Undersea Perspective Program, which integrates seabed observation network, communication, navigation and positioning, with intelligent charging technologies to build an intelligent exploration network from water to the seabed. In addition, there is a Deep Blue Brain Project, which will build a marine internet of things with the goal to enhance the ability of intelligent services from data to customers. To date, breakthroughs have been made in research and development of cutting-edge marine technologies, providing new means for ocean observation and exploration. With respect to the ocean observation network, China has built a pilot mooring network with over one hundred sub-surface moorings and almost ten surface buoys in the western Pacific, South China Sea and the Indian Ocean over the past decade. In the next decade, it is essential to integrate observations, process studies and prediction/projection, so as to meet multiple demands of end users.}, keywords = {marine observation and exploration technology, three-dimensional observation network, Transparent Ocean, transparent state}, doi = {10.1360/tb-2020-0558}, url = {https://app.dimensions.ai/details/publication/pub.1130540202}, author = {Wu, Lixin and Chen, Zhaohui and Lin, Xiaopei and Liu, Yongzheng} } @article {RN167, title = {A Census of the Warm Core Rings of the Gulf Stream: 1980-2017}, journal = {Journal of Geophysical Research Oceans}, year = {2020}, type = {Journal Article}, abstract = {A census of Gulf Stream (GS) warm-core rings (WCRs) is presented based on 38 years (1980{\textendash}2017) of data. The census documents formation and demise times and locations, and formation size for all 961 WCRs formed in the study period that live for a week or more. A clear regime shift was observed around the Year 2000 and was reported by a subset of authors (Gangopadhyay et al., 2019, https://doi.org/10.1038/s41598-019-48661-9). The WCR formation over the whole region (75{\textendash}55{\textdegree}W) increased from an average of 18 per year during Regime 1 (1980{\textendash}1999) to 33 per year during Regime 2 (2000{\textendash}2017). For geographic analysis formation locations were grouped in four 5{\textdegree} zones between 75{\textdegree}W and 55{\textdegree}W. Seasonally, WCR formations show a significant summer maxima and winter minima, a pattern that is consistent through all zones and both temporal regimes. The lifespan and size distribution show progressively more rings with higher longevity and greater size when formed to the east of 70{\textdegree}W. The average lifespan of the WCRs in all four zones decreased by 20{\textendash}40\% depending on zones and/or seasons from Regime 1 to Regime 2, while the size distribution remained unchanged across regimes. The ring footprint index, a first-order signature of impact of the WCRs on the slope, increased significantly (26{\textendash}90\%) for all zones from Regime 1 to Regime 2, with the highest percent increase in Zone 2 (70{\textendash}65{\textdegree}W). This observational study establishes critical statistical and dynamical benchmarks for validating numerical models and highlights the need for further dynamical understanding of the GS-ring formation processes.}, doi = {10.1029/2019jc016033}, url = {https://app.dimensions.ai/details/publication/pub.1128843160}, author = {Gangopadhyay, Avijit and Gawarkiewicz, Glen and Silva, E. Nishchitha S. and Silver, Adrienne M. and Monim, M. and Clark, Jenifer} } @article {RN282, title = {CMIP6 Models Predict Significant 21st Century Decline of the Atlantic Meridional Overturning Circulation}, journal = {Geophysical Research Letters}, volume = {47}, number = {12}, year = {2020}, type = {Journal Article}, doi = {10.1029/2019gl086075}, url = {https://app.dimensions.ai/details/publication/pub.1127868240 https://onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2019GL086075}, author = {Weijer, W. and Cheng, W. and Garuba, O. A. and Hu, A. and Nadiga, B. T.} } @article {RN190, title = {Compact representation of temporal processes in echosounder time series via matrix decompositiona)}, journal = {Journal of the Acoustical Society of America}, volume = {148}, number = {6}, year = {2020}, pages = {3429-3442}, type = {Journal Article}, abstract = {The recent explosion in the availability of echosounder data from diverse ocean platforms has created unprecedented opportunities to observe the marine ecosystems at broad scales. However, the critical lack of methods capable of automatically discovering and summarizing prominent spatio-temporal echogram structures has limited the effective and wider use of these rich datasets. To address this challenge, a data-driven methodology is developed based on matrix decomposition that builds compact representation of long-term echosounder time series using intrinsic features in the data. In a two-stage approach, noisy outliers are first removed from the data by principal component pursuit, then a temporally smooth nonnegative matrix factorization is employed to automatically discover a small number of distinct daily echogram patterns, whose time-varying linear combination (activation) reconstructs the dominant echogram structures. This low-rank representation provides biological information that is more tractable and interpretable than the original data, and is suitable for visualization and systematic analysis with other ocean variables. Unlike existing methods that rely on fixed, handcrafted rules, this unsupervised machine learning approach is well-suited for extracting information from data collected from unfamiliar or rapidly changing ecosystems. This work forms the basis for constructing robust time series analytics for large-scale, acoustics-based biological observation in the ocean. }, issn = {0001-4966}, doi = {10.1121/10.0002670}, author = {Lee, W. J. and Staneva, V.} } @article {RN215, title = {Continuous evolution of oceanic crustal structure following an eruption at Axial Seamount, Juan de Fuca Ridge}, journal = {Geology}, volume = {48}, number = {5}, year = {2020}, pages = {452-456}, type = {Journal Article}, abstract = {We present the first continuous observations of the temporal evolution of oceanic crustal shear velocity beneath Axial Seamount, a submarine volcano on the Juan de Fuca Ridge (offshore northwestern North America). Weekly values of seafloor compliance, the periodic deformation of the seafloor under ocean waves, were estimated over the time period between December 2014 and May 2018 using data from two cabled broadband ocean-bottom seismometers with collocated absolute pressure sensors. We inverted these measurements for shear-wave velocity within the volcano beneath the two stations as a function of depth and time. Our results, combined with estimates of seismic compressional wave velocity, suggest that the shallow melt reservoir and the lower crust beneath the central caldera contain melt fractions of 14\% and at least 4\%, respectively. The eruption of April 2015 induced a dramatic drop in shear velocities beneath the central station, primarily in the lower crust, which could have been caused by an increase in melt fraction, a change in small-scale melt geometry, or both. The absence of such a change beneath the eastern flank of the caldera indicates that there is a lower-crustal conduit beneath the caldera center, which is much narrower in cross section (<1 km2) than the overlying melt reservoir (>=42 km2). Our study demonstrates the promise of using continuous data to understand submarine volcanism and crustal accretionary processes.}, issn = {0091-7613}, doi = {10.1130/G46831.1}, url = {https://doi.org/10.1130/G46831.1}, author = {Doran, Adrian K. and Crawford, Wayne C.} } @article {RN179, title = {Crustal Strength Variations Inferred from Earthquake Stress Drop at Axial Seamount Surrounding the 2015 Eruption}, journal = {Geophysical Research Letters}, year = {2020}, type = {Journal Article}, abstract = {Variations in stress drops of earthquakes associated with the April and May 2015 eruption of Axial Seamount, on the Juan de Fuca Ridge, suggest a reduction in crustal strength as a result of the eruption. Seismicity during the inflation and deflation periods was well recorded by ocean bottom seismometers located within and along the caldera. We use these nearby recordings and an empirical Green{\textquoteright}s function spectral ratio method to obtain corner frequencies for stress drops of earthquakes on caldera ring faults. We find stress drops from 0.6 to 43 MPa for 423 ring fault earthquakes (1.6 <= MW <= 3.6) and an average stress drop two times higher during the inflation period (6.4 MPa) prior to the eruption, than during the subsequent deflation (3.2 MPa). Stress drops also correlate with spatially varying shear wave speed, possibly reflecting a region of pervasive cracking in the northern caldera.}, doi = {10.1029/2020gl088447}, url = {https://app.dimensions.ai/details/publication/pub.1129927688}, author = {Moyer, Pamela A. and Boettcher, Margaret S. and Bohnenstiehl, Del Wayne R. and Abercrombie, Rachel E.} } @article {RN177, title = {Deep Learning for Predicting Significant Wave Height From Synthetic Aperture Radar}, journal = {IEEE Transactions on Geoscience and Remote Sensing}, volume = {PP}, number = {99}, year = {2020}, pages = {1-9}, type = {Journal Article}, abstract = {The Sentinel-1 satellites equipped with synthetic aperture radars (SARs) provide near-global coverage of the world{\textquoteright}s oceans every six days. We curate a data set of collocations between SAR and altimeter satellites and investigate the use of deep learning to predict significant wave height from SAR. While previous models for predicting geophysical quantities from SAR rely heavily on feature-engineering, our approach learns directly from low-level image cross-spectra. Training on collocations from 2015 to 2017, we demonstrate on test data from 2018 that deep learning reduces the state-of-the-art root mean squared error by 50\%, from 0.6 to 0.3 m when compared to altimeter data. Furthermore, we isolate the contributions of different features to the model performance.}, keywords = {Data models, Modulation, Satellites, Sea measurements, Sea surface, Synthetic aperture radar}, doi = {10.1109/tgrs.2020.3003839}, url = {https://app.dimensions.ai/details/publication/pub.1129457664}, author = {Quach, Brandon and Glaser, Yannik and Stopa, Justin Edward and Mouche, Alexis Aurelien and Sadowski, Peter} } @article {RN175, title = {Disentangling knowledge production and data production}, journal = {Ecosphere}, volume = {11}, number = {7}, year = {2020}, type = {Journal Article}, abstract = {With today{\textquoteright}s increasing attention to open science and open data, knowledge production and data production have significant impacts on both research and policy arenas. We scrutinize the concept of data production in relation to knowledge production in the earth and environmental sciences. We present three empirical cases that illustrate issues arising when knowledge production and data production as interdependent but distinct processes are not clear in the mind of researchers and policymakers. A two-stream model is developed that highlights their interplay yet avoids the conflation of knowledge and data production. This approach highlights knowledge and data in terms of processes rather than stable objects or assets. Further, we suggest that considering knowledge and data production in relation to their development by communities rather than as commodities helps in understanding the debates and issues that arise in contemporary research practice.}, doi = {10.1002/ecs2.3191}, url = {https://app.dimensions.ai/details/publication/pub.1129380574 http://dx.doi.org/10.1002/ecs2.3191}, author = {Baker, Karen S. and Mayernik, Matthew S.} } @article {RN174, title = {Estimating Southern Ocean Storm Positions With Seismic Observations}, journal = {Journal of Geophysical Research Oceans}, volume = {125}, number = {4}, year = {2020}, type = {Journal Article}, abstract = {Surface winds from Southern Ocean cyclones generate large waves that travel over long distances (>1,000 km). Wave generation regions are often colocated with enhanced air-sea fluxes and upper ocean mixing. Ocean wave spectra contain information about storm wind speed, fetch size, and intensity at their generation site. Two years of seismic observations on the Ross Ice shelf, combined with modern optimization (machine learning) techniques, are used to trace the origins of wave events in the Southern Ocean with an accuracy of {\textpm}110 km and {\textpm}2 hr from a hypothetical point source. The observed spectral energy attenuated within sea ice and in the ice shelf but retains characteristics that can be compared to parametric wave models. Comparison with the Modern-Era Retrospective Analysis for Research and Applications, Version 2, and ERA5 reanalyses suggests that less than 45\% of ocean swell events can be associated with individual Southern Ocean storms, while the majority of the observed wave events cannot be matched with Southern Ocean high wind events. Reanalysis cyclones and winds are often displaced by about 350 km or 10 hr in Modern-Era Retrospective Analysis for Research and Applications, Version 2, and ERA5 compared to the most likely positions inferred from the seismic spectra. This high fraction of displaced storms in reanalysis products over the South Pacific can be explained by the limited availability of remote sensing observations, primarily caused by the presence of sea ice. Deviation of wave rays from their great circle path by wave-current interaction plays a minor role.}, doi = {10.1029/2019jc015898}, url = {https://app.dimensions.ai/details/publication/pub.1126055069 https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2019JC015898}, author = {Hell, Momme C. and Gille, Sarah T. and Cornuelle, Bruce D. and Miller, Arthur J. and Bromirski, Peter D. and Crawford, Alex D.} } @article {RN199, title = {The evolution of biogeochemistry: revisited}, journal = {Biogeochemistry}, year = {2020}, pages = {1-41}, type = {Journal Article}, abstract = {The evolution of biogeochemistry, retraces the important historical steps in part, covered by Gorham (Biogeochemistry 13:199{\textendash}239, 1991) in the 18{\textendash}19th centuries{\textemdash}with new emergent linkages and trends in 20{\textendash}21st centuries. In the post-phlogiston period, key synthetic connections are made between weathering, atmospheric chemistry, carbon cycling, and climate change. Early work in the 19th century, focused on weathering and the importance of organisms in the exchange of carbon dioxide between the rocks and the atmosphere, provided foundations for new analytical approaches. The role microbes in connecting abiotic and biotic processes begins to emerge, based largely on the existing knowledge of stoichiometry in agricultural soils and plants. This in part, leads to the founding of ecology and its linkages with evolution and biogeography. Verandsky boldly emerges in the 20th century, with his concepts of a biosphere and a noosphere, as concerns begin to arise about human impacts on nature. The development of organic geochemistry as a discipline, allowed for new roots to develop in the evolution of biogeochemistry through linkages between short and long-term carbon cycles. In the 20th century, a new interesting stoichiometry emerges in biogeochemistry{\textemdash}as related to the Green Revolution, human population growth, and eutrophication problems. The advent of long-term and large-scale experiments help to constrain the complexity of non-linearity and regional differences in fluxes and rates in biogeochemical work. A new age begins in the 21st century whereby molecular approaches (e.g. omics) combined with large-scale satellite, monitoring, survey, observatory approaches are combined in the development of Earth System models. These new connections with ecological/evolutionary genetics are one of the more dramatic and important aspects of biogeochemistry in modern times. }, keywords = {Biogeochemistry, Earth science, Ecology, Evolution geochemistry, Global change}, doi = {10.1007/s10533-020-00708-0}, url = {https://app.dimensions.ai/details/publication/pub.1132940992 https://link.springer.com/content/pdf/10.1007/s10533-020-00708-0.pdf}, author = {Bianchi, Thomas S.} } @article {RN136, title = {The Hierarchic Treatment of Marine Ecological Information from Spatial Networks of Benthic Platforms}, journal = {Sensors}, volume = {20}, number = {6}, year = {2020}, pages = {1751}, type = {Journal Article}, abstract = {Measuring biodiversity simultaneously in different locations, at different temporal scales, and over wide spatial scales is of strategic importance for the improvement of our understanding of the functioning of marine ecosystems and for the conservation of their biodiversity. Monitoring networks of cabled observatories, along with other docked autonomous systems (e.g., Remotely Operated Vehicles [ROVs], Autonomous Underwater Vehicles [AUVs], and crawlers), are being conceived and established at a spatial scale capable of tracking energy fluxes across benthic and pelagic compartments, as well as across geographic ecotones. At the same time, optoacoustic imaging is sustaining an unprecedented expansion in marine ecological monitoring, enabling the acquisition of new biological and environmental data at an appropriate spatiotemporal scale. At this stage, one of the main problems for an effective application of these technologies is the processing, storage, and treatment of the acquired complex ecological information. Here, we provide a conceptual overview on the technological developments in the multiparametric generation, storage, and automated hierarchic treatment of biological and environmental information required to capture the spatiotemporal complexity of a marine ecosystem. In doing so, we present a pipeline of ecological data acquisition and processing in different steps and prone to automation. We also give an example of population biomass, community richness and biodiversity data computation (as indicators for ecosystem functionality) with an Internet Operated Vehicle (a mobile crawler). Finally, we discuss the software requirements for that automated data processing at the level of cyber-infrastructures with sensor calibration and control, data banking, and ingestion into large data portals.}, keywords = {artificial intelligence, cabled observatories, crawler, cyber-infrastructures, data banking, ecological indicators, ecological information treatment, imaging}, doi = {10.3390/s20061751}, author = {Aguzzi, Jacopo and Chatzievangelou, Damianos and Francescangeli, Marco and Marini, Simone and Bonofiglio, Federico and del Rio, Joaquin and Danovaro, Roberto} } @article {RN173, title = {Learning features from georeferenced seafloor imagery with location guided autoencoders}, journal = {Journal of Field Robotics}, year = {2020}, type = {Journal Article}, abstract = {The Cabled Observatory Vent Imaging Sonar (COVIS) was installed on the Ocean Observatories Initiative{\textquoteright}s Regional Cabled Array observatory at ASHES hydrothermal vent field on Axial Seamount in July 2018. The acoustic backscatter data recorded by COVIS in August{\textendash}September 2018, in conjunction with in situ temperature measurements, are used to showcase and verify the use of COVIS for long-term, quantitative monitoring of hydrothermal discharge. Specifically, sonar data processing generates three-dimensional backscatter images of the buoyant plumes above major sulfide structures and two-dimensional maps of diffuse flows within COVIS{\textquoteright}s field-of-view. The backscatter images show substantial changes of plume appearance and orientation that mostly reflect plume bending in the presence of ambient currents and potentially the variations of outflow fluxes. The intensity of acoustic backscatter decreases significantly for highly bent plumes as compared to nearly vertical plumes, reflecting enhanced mixing of plume fluids with seawater driven by ambient currents. A forward model of acoustic backscatter from a buoyancy-driven plume developed in this study yields a reasonable match with the observation, which paves the way for inversely estimating the source heat flux of a hydrothermal plume from acoustic backscatter measurements. The acoustic observations of diffuse flows show large temporal variations on time scales of hours to days, especially at tidal frequencies, but no apparent long-term trend. These findings demonstrate COVIS{\textquoteright}s ability to quantitatively monitor hydrothermal discharge from both focused and diffuse sources to provide the research community with key observational data for studying the linkage of hydrothermal activity with oceanic and geological processes.}, keywords = {acoustic, axial seamount, hydrothermal, imaging, observatory, sonar}, doi = {10.1002/rob.21961}, url = {https://app.dimensions.ai/details/publication/pub.1127976526}, author = {Yamada, Takaki and Pr{\"u}gel-Bennett, Adam and Thornton, Blair} } @article {RN280, title = {Mean Conditions and Seasonality of the West Greenland Boundary Current System near Cape Farewell}, journal = {Journal of Physical Oceanography}, volume = {50}, number = {10}, year = {2020}, pages = {2849-2871}, type = {Journal Article}, doi = {10.1175/jpo-d-20-0086.1}, url = {https://app.dimensions.ai/details/publication/pub.1130194077 http://nora.nerc.ac.uk/id/eprint/528563/1/jpod200086.pdf}, author = {Pacini, Astrid and Pickart, Robert S. and Bahr, Frank and Torres, Daniel J. and Ramsey, Andr{\'e}e L. and Holte, James and Karstensen, Johannes and Oltmanns, Marilena and Straneo, Fiammetta and Le Bras, Isabela Astiz and Moore, G. W. K. and de Jong, M. Femke} } @article {RN165, title = {Measurement and Quality Control of MIROS Wave Radar Data at Dokdo}, journal = {Journal of Korean Society of Coastal and Ocean Engineers}, volume = {32}, number = {2}, year = {2020}, pages = {135-145}, type = {Journal Article}, abstract = {Wave observation is widely used to direct observation method for observing the water surface elevation using wave buoy or pressure gauge and remote-sensing wave observation method. The wave buoy and pressure gauge can produce high-quality wave data but have disadvantages of the high risk of damage and loss of the instrument, and high maintenance cost in the offshore area. On the other hand, remote observation method such as radar is easy to maintain by installing the equipment on the land, but the accuracy is somewhat lower than the direct observation method. This study investigates the data quality of MIROS Wave and Current Radar (MWR) installed at Dokdo and improve the data quality of remote wave observation data using the wave buoy (CWB) observation data operated by the Korea Meteorological Administration. We applied and developed the three types of wave data quality control; 1) the combined use (Optimal Filter) of the filter designed by MIROS (Reduce Noise Frequency, Phillips Check, Energy Level Check), 2) Spike Test Algorithm (Spike Test) developed by OOI (Ocean Observatories Initiative) and 3) a new filter (H-Ts QC) using the significant wave height-period relationship. As a result, the wave observation data of MWR using three quality control have some reliability about the significant wave height. On the other hand, there are still some errors in the significant wave period, so improvements are required. Also, since the wave observation data of MWR is different somewhat from the CWB data in high waves of over 3 m, further research such as collection and analysis of long-term remote wave observation data and filter development is necessary.}, keywords = {data processing, Dokdo, quality control, quality enhancement of wave data, wave and current radar}, doi = {10.9765/kscoe.2020.32.2.135}, url = {https://app.dimensions.ai/details/publication/pub.1127450425 http://jkscoe.or.kr/upload/pdf/jkscoe-32-2-135.pdf}, author = {Jun, Hyunjung and Min, Yongchim and Jeong, Jin-Yong and Do, Kideok} } @article {RN153, title = {Mooring Observations of Air-Sea Heat Fluxes in Two Subantarctic Mode Water Formation Regions}, journal = {Journal of Climate}, volume = {33}, number = {7}, year = {2020}, pages = {2757-2777}, type = {Journal Article}, abstract = {Wintertime surface ocean heat loss is the key process driving the formation of Subantarctic Mode Water (SAMW), but there are few direct observations of heat fluxes, particularly during winter. The Ocean Observatories Initiative (OOI) Southern Ocean mooring in the southeast Pacific Ocean and the Southern Ocean Flux Station (SOFS) in the southeast Indian Ocean provide the first concurrent, multiyear time series of air{\textendash}sea fluxes in the Southern Ocean from two key SAMW formation regions. In this work we compare drivers of wintertime heat loss and SAMW formation by comparing air{\textendash}sea fluxes and mixed layers at these two mooring locations. A gridded Argo product and the ERA5 reanalysis product provide temporal and spatial context for the mooring observations. Turbulent ocean heat loss is on average 1.5 times larger in the southeast Indian (SOFS) than in the southeast Pacific (OOI), with stronger extreme heat flux events in the southeast Indian leading to larger cumulative winter ocean heat loss. Turbulent heat loss events in the southeast Indian (SOFS) occur in two atmospheric regimes (cold air from the south or dry air circulating via the north), while heat loss events in the southeast Pacific (OOI) occur in a single atmospheric regime (cold air from the south). On interannual time scales, wintertime anomalies in net heat flux and mixed layer depth (MLD) are often correlated at the two sites, particularly when wintertime MLDs are anomalously deep. This relationship is part of a larger basin-scale zonal dipole in heat flux and MLD anomalies present in both the Indian and Pacific basins, associated with anomalous meridional atmospheric circulation.}, keywords = {Atmosphere-ocean interaction, Buoy observations, Heat budgets/fluxes, Oceanic mixed layer, Southern Ocean, Water masses/storage}, issn = {0894-8755}, doi = {10.1175/JCLI-D-19-0653.1}, author = {Tamsitt, V. and Cerovecki, I. and Josey, S. A. and Gille, S. T. and Schulz, E.} } @article {RN159, title = {New insights into the structural elements of the upper mantle beneath the contiguous United States from S-to-P converted seismic waves}, journal = {Geophysical Journal International}, volume = {222}, number = {1}, year = {2020}, pages = {646-659}, type = {Journal Article}, abstract = {The S-receiver function (SRF) technique is an effective tool to study seismic discontinuities in the upper mantle such as the mid-lithospheric discontinuity (MLD) and the lithosphere{\textendash}asthenosphere boundary (LAB). This technique uses deconvolution and aligns traces along the maximum of the deconvolved SV signal. Both of these steps lead to acausal signals, which may cause interference with real signals from below the Moho. Here we go back to the origin of the SRF method and process S-to-P converted waves using S-onset times as the reference time and waveform summation without any filter like deconvolution or bandpass. We apply this {\textquoteleft}causal{\textquoteright} SRF (C-SRF) method to data of the USArray and obtain partially different results in comparison with previous studies using the traditional acausal SRF method. The new method does not confirm the existence of an MLD beneath large regions of the cratonic US. The shallow LAB in the western US is, however, confirmed with the new method. The elimination of the MLD signal below much of the cratonic US reveals lower amplitude but highly significant phases that previously had been overwhelmed by the apparent MLD signals. Along the northern part of the area with data coverage we see relics of Archean or younger northwest directed low-angle subduction below the entire Superior Craton. In the cratonic part of the US we see indications of the cratonic LAB near 200 km depth. In the Gulf Coast of the southern US, we image relics of southeast directed shallow subduction, likely of mid-Palaeozoic age.}, issn = {0956-540X}, doi = {10.1093/gji/ggaa203}, author = {Kind, R. and Mooney, W. D. and Yuan, X. H.} } @article {RN143, title = {A Novel Fault Location Approach for Scientific Cabled Seafloor Observatories}, journal = {Journal of Marine Science and Engineering}, volume = {8}, number = {3}, year = {2020}, pages = {190}, type = {Journal Article}, abstract = {The maintenance of scientific cabled seafloor observatories (CSOs) is not only extremely difficult but also of high cost for their subsea location. Therefore, the cable fault detection and location are essential and must be carried out accurately. For this purpose, a novel on-line fault location approach based on robust state estimation is proposed, considering state data gross errors in sensor measurements and the influence of temperature on system parameter variation. The circuit theory is used to build state estimation equations and identify the power system topology of faulty CSOs. This method can increase the accuracy of fault location, and reduce the lose form shutting down a faulty CSO in traditional fault location methods. It is verified by computer simulation and the laboratory prototype of a planned CSO in the East China Sea, and the fault location error is proved to be less than 1 km.}, keywords = {cabled seafloor observatories, on-line fault location, robust state estimation, topology identification}, doi = {10.3390/jmse8030190}, url = {https://app.dimensions.ai/details/publication/pub.1125648256}, author = {Yang, Fan and Lyu, Feng} } @article {RN186, title = {An Object Model for Seafloor Observatory Sensor Control in the East China Sea}, journal = {Journal of Marine Science and Engineering}, volume = {8}, number = {9}, year = {2020}, pages = {716}, type = {Journal Article}, abstract = {Seafloor observatories enable long-term, real-time, and continuous observation that marks a new way for oceanographic measurements. In terms of seafloor observatory research, sensor control is a key issue for the stable and effective operations of functional observatories. In this paper, an object model is proposed to standardize seafloor observatory sensor control and data acquisition. The object model is conceptionally designed as a set of sensor resource objects, based on the attributes and operations of which a client{\textendash}server sensor control architecture is enabled for bidirectional information flow of control commands and observation data. The object model-based architecture is implemented with a prototype control system for plug-and-play enablement. The prototype system was put into a series of tests before applied to the East China Sea Experimental Seafloor Observatory, performing consistently with all the project requirements. Given the successful experiment, the object model design and prototype implementation are feasible to resolve seafloor observatory sensor control and beneficial for ocean observatory sciences.}, keywords = {in situ measurements, object model, seafloor observatories, sensor control}, doi = {10.3390/jmse8090716}, url = {https://app.dimensions.ai/details/publication/pub.1130914583}, author = {Yu, Yang and Xu, Huiping and Xu, Changwei} } @article {RN172, title = {Obsea: A Decadal Balance for a Cabled Observatory Deployment}, journal = {IEEE Access}, volume = {8}, year = {2020}, pages = {33163-33177}, type = {Journal Article}, abstract = {The study of the effects of climate change on the marine environment requires the existence of sufficiently long time series of key parameters. The study of these series allows both to characterize the range of variability in each particular region and to detect trends or changes that could be attributed to anthropogenic causes. For this reason, networks of permanent cabled observation systems are being deployed in the ocean. This paper presents a balance of a decade of activity at the OBSEA cabled observatory, as an example of ocean monitoring success and drawbacks. It is not the objective of this article to analyze the scientific and technical aspects already presented by the authors in different publications (Table 4). We will evaluate the overall experience by retracing the different steps of infrastructure deployment and maintenance, focusing on routines for in situ control, damages experienced, breakdowns and administrative constraints by local administrations. We will conclude by providing a set of guidelines to improve cabled observatories scientific outreach, societal projection, and economic efficiency. As a result of this work, a 10-years dataset has been published in Pangaea that is available for the community.}, keywords = {Europe, Instruments, monitoring, Observatories, Oceans, Sea measurements, Underwater cables}, doi = {10.1109/access.2020.2973771}, url = {https://app.dimensions.ai/details/publication/pub.1125026314 https://ieeexplore.ieee.org/ielx7/6287639/8948470/08998177.pdf}, author = {Del-Rio, Joaquin and Nogueras, Marc and Toma, Daniel Mihai and Mart{\'\i}nez, Enoc and Artero-Delgado, Carola and Bghiel, Ikram and Martinez, Marc and Cadena, Javier and Garcia-Benadi, Albert and Sarria, David and Aguzzi, Jacopo and Masmitja, Ivan and Carandell, Matias and Olive, Joaquim and Gomariz, Spartacus and Santamaria, Pep and L{\`a}zaro, Antoni M{\`a}nuel} } @article {RN196, title = {Observation impacts on the Mid-Atlantic Bight front and cross-shelf transport in 4D-Var ocean state estimates: Part I {\textemdash} Multiplatform analysis}, journal = {Ocean Modelling}, volume = {156}, year = {2020}, pages = {101721}, type = {Journal Article}, abstract = {The Regional Ocean Modeling System (ROMS) 4-dimensional variational (4D-Var) data assimilation system was used to compute ocean state estimates of the Mid-Atlantic Bight (MAB). A three-level nested grid configuration was employed with horizontal resolution successively enhanced from 7 km down to 800 m at the innermost nest. This captures the dynamics on space- and time-scales ranging from the Gulf Stream western boundary current down to the rapidly evolving and energetic sub-mesoscale circulation. This is a companion study to Levin et al. (2020) which examined the overall impacts of the entire observing system on shelf-break exchange. This follow-on study specifically focuseson the impact of the in situ elements of the ocean observing system on the 4D-Var analyses. The particular focus here is on the Pioneer Array, a high-density observing system in the MAB designed to measure the multi-scale nature of shelf-break exchange processes. Building on Levin et al. (2020), it is found that the relative impact of observations from different components of the Pioneer Array depends on the scales of motion that are resolved by each nested grid. This is in apparent agreement with the linear theory of geostrophic adjustment despite the O(1) Rossby number. The synergy between the observations from different observing platforms has also been quantified by comparing the observation impacts with the sensitivity of the 4D-Var analyses to changes in the observing array. It is found that while some observations do not have a significant direct impact on the analyses, they nevertheless provide essential information about the presence of circulation features, corroborating that measured by other sensors. Thus, the individual parts of the observing system can borrow strength from each other. Finally, the contribution of each component of the observing system to the expected error in the 4D-Var analyses was also quantified, where the critical role played by the Pioneer Array moorings in resolving the sub-mesoscale circulation is again highlighted.}, keywords = {Mid-Atlantic Bight, Observation impact, Observation sensitivity, Pioneer Array, ROMS 4D-Var}, doi = {10.1016/j.ocemod.2020.101721}, url = {https://app.dimensions.ai/details/publication/pub.1132245849}, author = {Levin, Julia and Arango, Hernan G. and Laughlin, Bruce and Hunter, Elias and Wilkin, John and Moore, Andrew M.} } @article {RN289, title = {The Observation-Based Application of a Regional Thermohaline Inverse Method to Diagnose the Formation and Transformation of Water Masses North of the OSNAP Array from 2013 to 2015}, journal = {Journal of Physical Oceanography}, volume = {50}, number = {6}, year = {2020}, pages = {1533-1555}, type = {Journal Article}, doi = {10.1175/jpo-d-19-0188.1}, url = {https://app.dimensions.ai/details/publication/pub.1124867712 https://journals.ametsoc.org/downloadpdf/journals/phoc/50/6/JPO-D-19-0188.1.pdf}, author = {Mackay, Neill and Wilson, Chris and Holliday, N. Penny and Zika, Jan D.} } @article {RN171, title = {Ocean Observation Technologies: A Review}, journal = {Chinese Journal of Mechanical Engineering}, volume = {33}, number = {1}, year = {2020}, pages = {32}, type = {Journal Article}, abstract = {Covering about three quarters of the surface area of the earth, the ocean is a critical source of sustenance, medicine, and commerce. However, such vast expanse in both surface area and depth, presents myriad observing challenges for researchers, such as corrosion, attenuation of electromagnetic waves, and high pressure. Ocean observation technologies are progressing from the conventional single node, static and short-term modalities to multiple nodes, dynamic and long-term modalities, to increase the density of both temporal and spatial samplings. Although people{\textquoteright}s knowledge of the oceans has been still quite limited, the contributions of many nations cooperating to develop the Global Ocean Observing System (GOOS) have remarkably promoted the development of ocean observing technologies. This paper reviews the typical observing technologies deployed from the sea surface to the seafloor, and discusses the future trend of the ocean observation systems with the docking technology and sustained ocean energy. }, keywords = {Docking, observatory, Ocean energyl AUV, Ocean observation, Recharging, Sampling, Underwater}, doi = {10.1186/s10033-020-00449-z}, url = {https://app.dimensions.ai/details/publication/pub.1126707055 https://cjme.springeropen.com/track/pdf/10.1186/s10033-020-00449-z}, author = {Lin, Mingwei and Yang, Canjun} } @article {RN189, title = {Open Data, Collaborative Working Platforms, and Interdisciplinary Collaboration: Building an Early Career Scientist Community of Practice to Leverage Ocean Observatories Initiative Data to Address Critical Questions in Marine Science}, journal = {Frontiers in Marine Science}, volume = {7}, year = {2020}, type = {Journal Article}, abstract = {Ocean observing systems are well-recognized as platforms for long-term monitoring of near-shore and remote locations in the global ocean. High-quality observatory data is freely available and accessible to all members of the global oceanographic community{\textemdash}a democratization of data that is particularly useful for early career scientists (ECS), enabling ECS to conduct research independent of traditional funding models or access to laboratory and field equipment. The concurrent collection of distinct data types with relevance for oceanographic disciplines including physics, chemistry, biology, and geology yields a unique incubator for cutting-edge, timely, interdisciplinary research. These data are both an opportunity and an incentive for ECS to develop the computational skills and collaborative relationships necessary to interpret large data sets. Here, we use observatory data to demonstrate the potential for these interdisciplinary approaches by presenting a case study on the water-column response to anomalous atmospheric events (i.e., major storms) on the shelf of the Mid-Atlantic Bight southwest of Cape Cod, United States. Using data from the Ocean Observatories Initiative (OOI) Pioneer Array, we applied a simple data mining method to identify anomalous atmospheric events over a four-year period. Two closely occurring storm events in late 2018 were then selected to explore the dynamics of water-column response using mooring data from across the array. The comprehensive ECS knowledge base and computational skill sets allowed identification of data issues in the OOI data streams and technologically sound characterization of data from multiple sensor packages to broadly characterize ocean-atmosphere interactions. An ECS-driven approach that emphasizes collaborative and interdisciplinary working practices adds significant value to existing datasets and programs such as OOI and has the potential to produce meaningful scientific advances. Future success in utilizing ocean observatory data requires continued investment in ECS education, collaboration, and research; in turn, the ECS community provides feedback, develops knowledge, and builds new tools to enhance the value of ocean observing systems. These findings present an argument for building a community of practice to augment ECS ocean scientist skills and foster collaborations to extend the context, reach, and societal utility of ocean science.}, keywords = {big data, COVID-19 pandemic, data mining, early career researchers, middle Atlantic bight, ocean observing, ocean response, remote collaboration}, doi = {10.3389/fmars.2020.593512}, author = {Levine, R. M. and Fogaren, K. E. and Rudzin, J. E. and Russoniello, C. J. and Soule, D. C. and Whitaker, J. M.} } @article {RN169, title = {Optimal sensors placement for detecting CO2 discharges from unknown locations on the seafloor}, journal = {International Journal of Greenhouse Gas Control}, volume = {95}, year = {2020}, pages = {102951}, type = {Journal Article}, abstract = {Assurance monitoring of the marine environment is a required and intrinsic part of CO2 storage project. To reduce the costs related to the monitoring effort, the monitoring program must be designed with optimal use of instrumentation. Here we use solution of a classical set cover problem to design placement of an array of fixed chemical sensors with the purpose of detecting a seep of CO2 through the seafloor from an unknown location. The solution of the problem is not unique and different aspects, such as cost or existing infrastructure, can be added to define an optimal solution. We formulate an optimization problem and propose a method to generate footprints of potential seeps using an advection{\textendash}diffusion model and a stoichiometric method for detection of small seepage CO2 signals. We provide some numerical experiments to illustrate the concepts.}, keywords = {Chemical sensors, Monitoring design, Offshore, Optimal sensor placement, Subsea CO2 seepage}, doi = {10.1016/j.ijggc.2019.102951}, url = {https://app.dimensions.ai/details/publication/pub.1124683604 https://doi.org/10.1016/j.ijggc.2019.102951}, author = {Oleynik, Anna and Garc{\'\i}a-Ib{\'a}{\~n}ez, Maribel I. and Blaser, Nello and Omar, Abdirahman and Alendal, Guttorm} } @article {RN188, title = {Optimizing Mooring Placement to Constrain Southern Ocean Air-Sea Fluxes}, journal = {Journal of Atmospheric and Oceanic Technology}, volume = {37}, number = {8}, year = {2020}, pages = {1365-1385}, type = {Journal Article}, abstract = {Proposals from multiple nations to deploy air{\textendash}sea flux moorings in the Southern Ocean have raised the question of how to optimize the placement of these moorings in order to maximize their utility, both as contributors to the network of observations assimilated in numerical weather prediction and also as a means to study a broad range of processes driving air{\textendash}sea fluxes. This study, developed as a contribution to the Southern Ocean Observing System (SOOS), proposes criteria that can be used to determine mooring siting to obtain best estimates of net air{\textendash}sea heat flux (Qnet). Flux moorings are envisioned as one component of a multiplatform observing system, providing valuable in situ point time series measurements to be used alongside satellite data and observations from autonomous platforms and ships. Assimilating models (e.g., numerical weather prediction and reanalysis products) then offer the ability to synthesize the observing system and map properties between observations. This paper develops a framework for designing mooring array configurations to maximize the independence and utility of observations. As a test case, within the meridional band from 35{\textdegree} to 65{\textdegree}S we select eight mooring sites optimized to explain the largest fraction of the total variance (and thus to ensure the least variance of residual components) in the area south of 20{\textdegree}S. Results yield different optimal mooring sites for low-frequency interannual heat fluxes compared with higher-frequency subseasonal fluxes. With eight moorings, we could explain a maximum of 24.6\% of high-frequency Qnet variability or 44.7\% of low-frequency Qnet variability.}, keywords = {Buoy observations, In situ atmospheric observations, In situ oceanic observations, Southern Ocean}, issn = {0739-0572}, doi = {10.1175/JTECH-D-19-0203.1}, author = {Wei, Y. Z. and Gille, S. T. and Mazloff, M. R. and Tamsitt, V. and Swart, S. and Chen, D. K. and Newman, L.} } @article {RN185, title = {Physical Sources of High-Frequency Seismic Noise on Cascadia Initiative Ocean Bottom Seismometers}, journal = {Geochemistry Geophysics Geosystems}, year = {2020}, type = {Journal Article}, abstract = {Physical sources of high-frequency seismic noise in the ocean are investigated using data from the Cascadia Initiative (CI) ocean bottom seismometer (OBS) network, hindcasts of wind speed, waves, and the bottom currents predicted by a regional ocean circulation model and observed at sites on cabled observatories. Seismic data in the 5{\textendash}12 Hz band are considered because it is best for detecting regional earthquakes and lies between the frequencies of local microseisms and the seasonal whale calls. Median noise levels in this range vary by ~20 dB between sites at a given depth but on average decrease with increasing depth. On the continental shelf, the orbital motions of ocean waves are a major source of noise while at the quietest sites in the deep ocean, noise increases when wind speeds exceed ~10 m/s. On the continental slope and abyssal plain within about 100 km of the slope, seismic noise is not predicted at specific sites by the bottom currents in the ocean circulation model. In these regions, ocean currents are inferred to be the primary source of noise, because noise varies on tidal periods, is low on buried seismometers, and has spatial variations broadly consistent with those of median absolute currents. Comparisons between OBSs suggest that high-frequency noise is reduced by low-profile hydrodynamic designs but not by shielding. Many OBSs also record numerous short duration events on and near the continental shelf that have been attributed elsewhere to animals bumping into the sensor or gas bubbles moving through sediments.}, doi = {10.1029/2020gc009085}, url = {https://app.dimensions.ai/details/publication/pub.1131195022}, author = {Hilmo, Rose and Wilcock, William S. D.} } @article {RN183, title = {Precision Seismic Monitoring and Analysis at Axial Seamount Using a Real-Time Double-Difference System}, journal = {Journal of Geophysical Research-Solid Earth}, volume = {125}, number = {5}, year = {2020}, type = {Journal Article}, abstract = {Seven three-component ocean bottom seismometers (OBS) of the Ocean Observatories Initiative (OOI) Cabled Array on top of Axial Seamount are continuously streaming data in real time to the Incorporated Research Institutions for Seismology (IRIS). The OBS array records earthquakes from the submarine volcano which last erupted on 24 April 2015, about 4 months after the array came online. The OBS data have proven crucial in providing insight into the volcano structure and dynamics (Wilcock et al., 2016, https://doi.org/10.1126/science.aah5563). We implemented a real-time double-difference (RT-DD) monitoring system that automatically computes high-precision (tens of meters) locations of new earthquakes. The system{\textquoteright}s underlying double-difference base catalog includes nearly 100,000 earthquakes and was computed using kurtosis phase onset picks, cross-correlation phase delay times, and 3-D P and S velocity models to predict the data. The relocations reveal the fine-scale structures of long-lived, narrow (<200 m wide), outward dipping, convex faults on the east and west walls of the caldera that appear to form a figure 8-shaped ring fault system. These faults accommodate stresses caused by the inflation of magma prior to and deflation during eruptions. The east fault is segmented and pulled apart in east-west direction due to its interaction with the Juan de Fuca Ridge, which at this location forms an overlapping spreading center. The RT-DD system enables the monitoring and rapid analysis of variations in fine-scale seismic and fault properties and has the potential to improve prediction of timing and location of the next Axial eruption expected to occur in the 2022{\textendash}2023 time frame. }, issn = {2169-9313}, doi = {10.1029/2019JB018796}, author = {Waldhauser, F. and Wilcock, W. S. D. and Tolstoy, M. and Baillard, C. and Tan, Y. J. and Schaff, D. P.} } @article {RN168, title = {Project EDDIE: Using Real Data in Science Classrooms}, journal = {Oceanography}, volume = {33}, number = {2}, year = {2020}, type = {Journal Article}, doi = {10.5670/oceanog.2020.201}, url = {https://app.dimensions.ai/details/publication/pub.1126889237 https://tos.org/oceanography/assets/docs/33-2_soule.pdf}, author = {College, Queens and Soule, Dax} } @article {RN176, title = {Quantification of eruption dynamics on the north rift at Axial Seamount, Juan de Fuca Ridge}, journal = {Geochemistry Geophysics Geosystems}, year = {2020}, type = {Journal Article}, abstract = {Quantifying eruption dynamics in submarine environments is challenging. During the 2015 eruption of Axial Seamount, the formation of hummocky mounds along the north rift was accompanied by tens of thousands of impulsive acoustic signals generated by the interaction of lava and seawater. A catalog of these sounds was integrated with detailed seafloor mapping to better understand eruptive processes in time and space. Mounds grew over a period of 28 days with average extrusion rates of 22 to 45 m3 s-1. The most distant mounds, ~9.5 to 15.5 km down rift from the caldera, grew primarily over the first few days of the eruption. The focus of eruptive activity then retreated ~5 km toward the caldera where it was sustained. Mounds are constructed as a series of superimposed lobes formed through alternating periods of flow inflation, generating up to 30-m-thick hummocks, and periods of flow advancement, with <0.02 m s-1 average speeds typically observed.}, doi = {10.1029/2020gc009136}, url = {https://app.dimensions.ai/details/publication/pub.1129829964}, author = {Le Saout, M. and Bohnenstiehl, D. R. and Paduan, J. B. and Clague, D. A.} } @article {RN155, title = {Rapid Export of Waters Formed by Convection Near the Irminger Sea{\textquoteright}s Western Boundary}, journal = {Geophysical Research Letters}, volume = {47}, number = {3}, year = {2020}, type = {Journal Article}, abstract = {The standard view of the overturning circulation emphasizes the role of convection, yet for waters to contribute to overturning, they must not only be transformed to higher densities but also exported equatorward. From novel mooring observations in the Irminger Sea (2014{\textendash}2016), we describe two water masses that are formed by convection and show that they have different rates of export in the western boundary current. Upper Irminger Sea Intermediate Water appears to form near the boundary current and is exported rapidly within 3 months of its formation. Deep Irminger Sea Intermediate Water forms in the basin interior and is exported on longer time scales. The subduction of these waters into the boundary current is consistent with an eddy transport mechanism. Our results suggest that light intermediate waters can contribute to overturning as much as waters formed by deeper convection and that the export time scales of both project onto overturning variability.}, issn = {0094-8276}, doi = {10.1029/2019GL085989}, author = {Le Bras, I. A. A. and Straneo, F. and Holte, J. and de Jong, M. F. and Holliday, N. P.} } @article {RN178, title = {Reviews and syntheses: Bacterial bioluminescence {\textendash} ecology and impact in the biological carbon pump}, journal = {Biogeosciences}, volume = {17}, number = {14}, year = {2020}, pages = {3757-3778}, type = {Journal Article}, abstract = {Around 30 species of marine bacteria can emit light, a critical characteristic in the oceanic environment is mostly deprived of sunlight. In this article, we first review current knowledge on bioluminescent bacteria symbiosis in light organs. Then, focusing on gut-associated bacteria, we highlight that recent works, based on omics methods, confirm previous claims about the prominence of bioluminescent bacterial species in fish guts. Such host{\textendash}symbiont relationships are relatively well-established and represent important knowledge in the bioluminescence field. However, the consequences of bioluminescent bacteria continuously released from light organs and through the digestive tracts to the seawater have been barely taken into account at the ecological and biogeochemical level. For too long neglected, we propose considering the role of bioluminescent bacteria and reconsidering the biological carbon pump, taking into account the bioluminescence effect ({\textquotedblleft}bioluminescence shunt hypothesis{\textquotedblright}). Indeed, it has been shown that marine snow and fecal pellets are often luminous due to microbial colonization, which makes them a visual target. These luminous particles seem preferentially consumed by organisms of higher trophic levels in comparison to nonluminous ones. As a consequence, the sinking rate of consumed particles could be either increased (due to repackaging) or reduced (due to sloppy feeding or coprophagy/coprorhexy), which can imply a major impact on global biological carbon fluxes. Finally, we propose a strategy, at a worldwide scale, relying on recently developed instrumentation and methodological tools to quantify the impact of bioluminescent bacteria in the biological carbon pump.}, doi = {10.5194/bg-17-3757-2020}, url = {https://app.dimensions.ai/details/publication/pub.1129413438 https://www.biogeosciences.net/17/3757/2020/bg-17-3757-2020.pdf}, author = {Tanet, Lisa and Martini, S{\'e}verine and Casalot, Laurie and Tamburini, Christian} } @article {RN131, title = {Revised Magmatic Source Models for the 2015 Eruption at Axial Seamount Including Estimates of Fault-Induced Deformation}, journal = {Journal of Geophysical Research: Solid Earth}, volume = {125}, number = {4}, year = {2020}, type = {Journal Article}, abstract = {Axial Seamount is an active submarine volcano located at the intersection of the Cobb hot spot and the Juan de Fuca Ridge (45{\textdegree}57'N, 130{\textdegree}01'W). Bottom pressure recorders captured co-eruption subsidence of 2.4{\textendash}3.2 m in 1998, 2011, and 2015, and campaign-style pressure surveys every 1{\textendash}2 years have provided a long-term time series of inter-eruption re-inflation. The 2015 eruption occurred shortly after the Ocean Observatories Initiative (OOI) Cabled Array came online providing real-time seismic and deformation observations for the first time. Nooner and Chadwick (2016, https://doi.org/10.1126/science.aah4666) used the available vertical deformation data to model the 2015 eruption deformation source as a steeply dipping prolate-spheroid, approximating a high-melt zone or conduit beneath the eastern caldera wall. More recently, Levy et al. (2018, https://doi.org/10.1130/G39978.1) used OOI seismic data to estimate dip-slip motion along a pair of outward-dipping caldera ring faults. This fault motion complicates the deformation field by contributing up to several centimeters of vertical seafloor motion. In this study, fault-induced surface deformation was calculated from the slip estimates of Levy et al. (2018, https://doi.org/10.1130/G39978.1) then removed from vertical deformation data prior to model inversions. Removing fault motion resulted in an improved model fit with a new best-fitting deformation source located 2.11 km S64{\textdegree}W of the source of Nooner and Chadwick (2016, https://doi.org/10.1126/science.aah4666) with similar geometry. This result shows that ring fault motion can have a significant impact on surface deformation, and future modeling efforts need to consider the contribution of fault motion when estimating the location and geometry of subsurface magma movement at Axial Seamount.}, doi = {10.1029/2020jb019356}, url = {https://app.dimensions.ai/details/publication/pub.1125839587}, author = {Hefner, William L. and Nooner, Scott L. and Chadwick, William W. and Bohnenstiehl, DelWayne R.} } @article {RN127, title = {Scientific rationale and conceptual design of a process-oriented shelfbreak observatory: the OOI Pioneer Array}, journal = {Journal of Operational Oceanography}, volume = {13}, number = {1}, year = {2020}, pages = {19-36}, type = {Journal Article}, abstract = {The Ocean Observatories Initiative (OOI) of the National Science Foundation in the USA includes a coastal observatory called the OOI Pioneer Array, which is focused on understanding shelf/slope exchange processes. The OOI Pioneer Array has been designed and constructed and is currently in operation. In order to fully understand the design principles and constraints, we first describe the basic exchange processes and review prior experiments in the region. Emphasis is placed on the space and time scales of important exchange processes such as frontal meandering and warm core ring interactions with the Shelfbreak Front, the dominant sources of variability in the region. The three major components of the Pioneer Array are then described, including preliminary data from the underwater gliders and Autonomous Underwater Vehicle (AUV) deployments. The relevance of the Pioneer Array to important recent scientific issues in the area, including enhanced warming of the continental shelf and increasing frequency and spatial extent of Gulf Stream interactions with the continental shelf is discussed. Finally, similar observatories in Asia are briefly described, and general conclusions regarding principles that should guide the design of shelfbreak observatories in other geographic regions are presented.}, keywords = {Coastal observatoriesc, ocean observatory Initiative, ontinental shelf and slope processes}, issn = {1755-876X}, doi = {10.1080/1755876X.2019.1679609}, author = {Gawarkiewicz, G. and Plueddemann, A. J.} } @article {RN288, title = {Significance of Climate Indices to Benthic Conditions Across the Northern North Atlantic and Adjacent Shelf Seas}, journal = {Frontiers in Marine Science}, volume = {7}, year = {2020}, pages = {2}, type = {Journal Article}, doi = {10.3389/fmars.2020.00002}, url = {https://app.dimensions.ai/details/publication/pub.1124226079 https://www.frontiersin.org/articles/10.3389/fmars.2020.00002/pdf}, author = {Johnson, Clare and Inall, Mark and Gary, Stefan and Cunningham, Stuart} } @article {RN296, title = {A stable Atlantic Meridional Overturning Circulation in a changing North Atlantic Ocean since the 1990s}, journal = {Science Advances}, volume = {6}, number = {48}, year = {2020}, pages = {eabc7836}, type = {Journal Article}, doi = {10.1126/sciadv.abc7836}, url = {https://app.dimensions.ai/details/publication/pub.1132953582 https://www.science.org/doi/pdf/10.1126/sciadv.abc7836?download=true}, author = {Fu, Yao and Li, Feili and Karstensen, Johannes and Wang, Chunzai} } @article {RN279, title = {State of the Climate in 2019}, journal = {Bulletin of the American Meteorological Society}, volume = {101}, number = {8}, year = {2020}, pages = {s1-s429}, type = {Journal Article}, doi = {10.1175/2020bamsstateoftheclimate.1}, url = {https://app.dimensions.ai/details/publication/pub.1130094278 https://journals.ametsoc.org/downloadpdf/journals/bams/101/8/2020BAMSStateoftheClimate.pdf}, author = {Blunden, J. and Arndt, D. S.} } @article {RN149, title = {Sustainable Observations of the AMOC: Methodology and Technology}, journal = {Reviews of Geophysics}, volume = {58}, number = {1}, year = {2020}, pages = {e2019RG000654}, type = {Journal Article}, abstract = {The Atlantic Meridional Overturning Circulation (AMOC) is a key mechanism of heat, freshwater, and carbon redistribution in the climate system. The precept that the AMOC has changed abruptly in the past, notably during and at the end of the last ice age, and that it is {\textquotedblleft}very likely{\textquotedblright} to weaken in the coming century due to anthropogenic climate change is a key motivation for sustained observations of the AMOC. This paper reviews the methodology and technology used to observe the AMOC and assesses these ideas and systems for accuracy, shortcomings, potential improvements, and sustainability. We review hydrographic techniques and look at how these traditional techniques can meet modern requirements. Transport mooring arrays (TMAs) provide the {\textquotedblleft}gold standard{\textquotedblright} for sustained AMOC observing, utilizing dynamic height, current meter, and other instrumentation and techniques to produce continuous observations of the AMOC. We consider the principle of these systems and how they can be sustained and improved into the future. Techniques utilizing indirect measurements, such as satellite altimetry, coupled with in situ measurements, such as the Argo float array, are also discussed. Existing technologies that perhaps have not been fully exploited for estimating AMOC are reviewed and considered for this purpose. Technology is constantly evolving, and we look to the future of technology and how it can be deployed for sustained and expanded AMOC measurements. Finally, all of these methodologies and technologies are considered with a view to a sustained and sustainable future for AMOC observation.}, issn = {8755-1209}, doi = {10.1029/2019RG000654}, url = {https://doi.org/10.1029/2019RG000654}, author = {McCarthy, G. D. and Brown, P. J. and Flagg, C. N. and Goni, G. and Houpert, L. and Hughes, C. W. and Hummels, R. and Inall, M. and Jochumsen, K. and Larsen, K. M. H. and Lherminier, P. and Meinen, C. S. and Moat, B. I. and Rayner, D. and Rhein, M. and Roessler, A. and Schmid, C. and Smeed, D. A.} } @article {RN163, title = {Toward a Universal Frequency of Occurrence Distribution for Tsunamis: Statistical Analysis of a 32-Year Bottom Pressure Record at Axial Seamount}, journal = {Geophysical Research Letters}, volume = {47}, number = {10}, year = {2020}, type = {Journal Article}, abstract = {The Atlantic Meridional Overturning Circulation (AMOC) is a key mechanism of heat, freshwater, and carbon redistribution in the climate system. The precept that the AMOC has changed abruptly in the past, notably during and at the end of the last ice age, and that it is {\textquotedblleft}very likely{\textquotedblright} to weaken in the coming century due to anthropogenic climate change is a key motivation for sustained observations of the AMOC. This paper reviews the methodology and technology used to observe the AMOC and assesses these ideas and systems for accuracy, shortcomings, potential improvements, and sustainability. We review hydrographic techniques and look at how these traditional techniques can meet modern requirements. Transport mooring arrays (TMAs) provide the {\textquotedblleft}gold standard{\textquotedblright} for sustained AMOC observing, utilizing dynamic height, current meter, and other instrumentation and techniques to produce continuous observations of the AMOC. We consider the principle of these systems and how they can be sustained and improved into the future. Techniques utilizing indirect measurements, such as satellite altimetry, coupled with in situ measurements, such as the Argo float array, are also discussed. Existing technologies that perhaps have not been fully exploited for estimating AMOC are reviewed and considered for this purpose. Technology is constantly evolving, and we look to the future of technology and how it can be deployed for sustained and expanded AMOC measurements. Finally, all of these methodologies and technologies are considered with a view to a sustained and sustainable future for AMOC observation.}, doi = {10.1029/2020gl087372}, url = {https://app.dimensions.ai/details/publication/pub.1126751179}, author = {Fine, Isaac V. and Thomson, Richard E. and Chadwick, William W. and Fox, Christopher G.} } @article {RN160, title = {Towards Naples Ecological REsearch for Augmented Observatories (NEREA): The NEREA-Fix Module, a Stand-Alone Platform for Long-Term Deep-Sea Ecosystem Monitoring}, journal = {Sensors}, volume = {20}, number = {10}, year = {2020}, type = {Journal Article}, abstract = {Deep-sea ecological monitoring is increasingly recognized as indispensable for the comprehension of the largest biome on Earth, but at the same time it is subjected to growing human impacts for the exploitation of biotic and abiotic resources. Here, we present the Naples Ecological REsearch (NEREA) stand-alone observatory concept (NEREA-fix), an integrated observatory with a modular, adaptive structure, characterized by a multiparametric video-platform to be deployed in the Dohrn canyon (Gulf of Naples, Tyrrhenian Sea) at ca. 650 m depth. The observatory integrates a seabed platform with optoacoustic and oceanographic/geochemical sensors connected to a surface transmission buoy, plus a mooring line (also equipped with depth-staged environmental sensors). This reinforced high-frequency and long-lasting ecological monitoring will integrate the historical data conducted over 40 years for the Long-Term Ecological Research (LTER) at the station {\textquotedblleft}Mare Chiara{\textquotedblright}, and ongoing vessel-assisted plankton (and future environmental DNA-eDNA) sampling. NEREA aims at expanding the observational capacity in a key area of the Mediterranean Sea, representing a first step towards the establishment of a bentho-pelagic network to enforce an end-to-end transdisciplinary approach for the monitoring of marine ecosystems across a wide range of animal sizes (from bacteria to megafauna).}, keywords = {stand-alone observatory; optoacoustic imaging; ecological monitoring; remote data transmission; Artificial Intelligence}, doi = {10.3390/s20102911}, author = {Fanelli, E. and Aguzzi, J. and Marini, S. and del Rio, J. and Nogueras, M. and Canese, S. and Stefanni, S. and Danovaro, R. and Conversano, F.} } @article {RN138, title = {Trends in Physical Properties at the Southern New England Shelf Break}, journal = {Journal of Geophysical Research Oceans}, volume = {125}, number = {2}, year = {2020}, type = {Journal Article}, abstract = {We analyze 11 years (2003{\textendash}2013) of repeat temperature and salinity sections from across the New England shelf break south of Cape Cod during early summer (June{\textendash}July). The mean sections resolved the shelf break front which supports the Shelf Break Jet, a vital component of the regional circulation. Individual sections showed a great deal of variability associated with meanders in the shelf break front consistent with previous studies in the region. Over the 11 year record, the shelf region (inshore of the 100 m isobath) warmed by 0.26 {\textdegree}C yr urn:x-wiley:jgrc:media:jgrc23814:jgrc23814-math-0001, with the majority of this warming occurring shallower than 20 m (0.58 {\textdegree}C yr urn:x-wiley:jgrc:media:jgrc23814:jgrc23814-math-0002). The full-depth trend agrees well with previous studies of shelf warming to the north and the south of our study region. The temperature and salinity of the offshore edge of the Cold Pool Water on the shelf did not change significantly during this period. The surface warming on the shelf resulted in a decrease in near-surface density of 0.12 kg m urn:x-wiley:jgrc:media:jgrc23814:jgrc23814-math-0003 yr urn:x-wiley:jgrc:media:jgrc23814:jgrc23814-math-0004 and an increase in stratification between 10 and 15 m of urn:x-wiley:jgrc:media:jgrc23814:jgrc23814-math-0005 s urn:x-wiley:jgrc:media:jgrc23814:jgrc23814-math-0006 yr urn:x-wiley:jgrc:media:jgrc23814:jgrc23814-math-0007. Offshore of the shelf break, the Slope Water also warmed and became more saline by 0.21 {\textdegree}C yr urn:x-wiley:jgrc:media:jgrc23814:jgrc23814-math-0008 and 0.04 yr urn:x-wiley:jgrc:media:jgrc23814:jgrc23814-math-0009 respectively, resulting in a maximal reduction in density of 0.01 kg m urn:x-wiley:jgrc:media:jgrc23814:jgrc23814-math-0010 yr urn:x-wiley:jgrc:media:jgrc23814:jgrc23814-math-0011. In the Shelf Break Front, there is some evidence of freshening and a reduction in density, which may have resulted from an offshore shift in the Cold Pool but the statistical significance is small.}, doi = {10.1029/2019jc015784}, url = {https://app.dimensions.ai/details/publication/pub.1124209727 https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2019JC015784}, author = {Harden, B. E. and Gawarkiewicz, G. G. and Infante, M.} } @article {RN161, title = {Triggering of eruptions at Axial Seamount, Juan de Fuca Ridge}, journal = {Scientific Reports}, volume = {10}, number = {1}, year = {2020}, pages = {10219}, type = {Journal Article}, abstract = {The submarine volcano Axial Seamount has exhibited an inflation predictable eruption cycle, which allowed for the successful forecast of its 2015 eruption. However, the exact triggering mechanism of its eruptions remains ambiguous. The inflation predictable eruption pattern suggests a magma reservoir pressure threshold at which eruptions occur, and as such, an overpressure eruption triggering mechanism. However, recent models of volcano unrest suggest that eruptions are triggered when conditions of critical stress are achieved in the host rock surrounding a magma reservoir. We test hypotheses of eruption triggering using 3-dimensional finite element models which track stress evolution and mechanical failure in the host rock surrounding the Axial magma reservoir. In addition, we provide an assessment of model sensitivity to various temperature and non-temperature-dependent rheologies and external tectonic stresses. In this way, we assess the contribution of these conditions to volcanic deformation, crustal stress evolution, and eruption forecasts. We conclude that model rheology significantly impacts the predicted timing of through-going failure and eruption. Models consistently predict eruption at a reservoir pressure threshold of 12{\textendash}14 MPa regardless of assumed model rheology, lending support to the interpretation that eruptions at Axial Seamount are triggered by reservoir overpressurization. }, doi = {10.1038/s41598-020-67043-0}, url = {https://app.dimensions.ai/details/publication/pub.1128680799 https://www.nature.com/articles/s41598-020-67043-0.pdf}, author = {Cabaniss, Haley E. and Gregg, Patricia M. and Nooner, Scott L. and Chadwick, William W.} } @article {RN126, title = {USING AUTHENTIC DATA FROM NSF{\textquoteright}S OCEAN OBSERVATORIES INTIATIVE IN UNDERGRADUATE TEACHING An Invitation}, journal = {Oceanography}, volume = {33}, number = {1}, year = {2020}, pages = {62-73}, type = {Journal Article}, abstract = {There are many benefits to using real data in undergraduate science education, including building analytical and problem-solving skills and visualizing concepts through real-world examples. The Ocean Observatories Initiative (OOI) provides a unique source of continuous, long-term oceanographic data from multiple locations in the world ocean. Each of these arrays hosts a suite of co-located instruments that measure physical, chemical, geological, and biological properties. Existing educational resources derived from OOI data can be leveraged for undergraduate teaching activities in and beyond the classroom. We provide example applications of the use of OOI resources in lesson plans and in research experiences for undergraduates. There are also abundant opportunities for new resources to be developed by the community. Our goal is to guide educators in determining appropriate OOI data sets and applications for their own needs. }, issn = {1042-8275}, doi = {10.5670/oceanog.2020.103}, author = {Greengrove, C. and Lichtenwalner, C. S. and Palevsky, H. I. and Pfeiffer-Herbert, A. and Severmann, S. and Soule, D. and Murphy, S. and Smith, L. M. and Yarincik, K.} } @article {RN166, title = {The Virtual Data Collaboratory: A Regional Cyberinfrastructure for Collaborative Data-Driven Research}, journal = {Computing}, volume = {22}, number = {3}, year = {2020}, pages = {79-92}, type = {Journal Article}, abstract = {The Virtual Data Collaboratory is a federated data cyberinfrastructure designed to drive data-intensive, interdisciplinary, and collaborative research that will impact researchers, educators, and entrepreneurs across a broad range of disciplines and domains as well as institutional and geographic boundaries.}, keywords = {big data, Cloud computing, Collaboration, Computer architecture, Education, Software engineering, Virtual reality}, doi = {10.1109/mcse.2019.2908850}, url = {https://app.dimensions.ai/details/publication/pub.1113521625}, author = {Parashar, Manish and Simonet, Anthony and Rodero, Ivan and Ghahramani, Forough and Agnew, Grace and Jantz, Ron and Honavar, Vasant} } @article {RN187, title = {Warm Spiral Streamers over Gulf Stream Warm-Core Rings}, journal = {Journal of Physical Oceanography}, year = {2020}, pages = {1-58}, type = {Journal Article}, abstract = {This study examines the generation of warm spiral structures (referred to as spiral streamers here) over Gulf Stream warm-core rings. Satellite sea surface temperature imagery shows spiral streamers forming after warmer water from the Gulf Stream or newly formed warm-core rings impinges onto old warm-core rings and then intrudes into the old rings. Field measurements in April 2018 capture the vertical structure of a warm spiral streamer as a shallow lens of low-density water winding over an old ring. Observations also show subduction on both sides of the spiral streamer, which carries surface waters downward. Idealized numerical model simulations initialized with observed water-mass densities reproduce spiral streamers over warm-core rings and reveal that their formation is a nonlinear submesoscale process forced by mesoscale dynamics. The negative density anomaly of the intruding water causes a density front at the interface between the intruding water and surface ring water, which, through thermal wind balance, drives a local anticyclonic flow. The pressure gradient and momentum advection of the local interfacial flow push the intruding water toward the ring center. The large-scale anticyclonic flow of the ring and the radial motion of the intruding water together form the spiral streamer. The observed subduction on both sides of the spiral streamer is part of the secondary cross-streamer circulation resulting from frontogenesis on the stretching streamer edges. The surface divergence of the secondary circulation pushes the side edges of the streamer away from each other, widens the warm spiral on the surface, and thus enhances its surface signal.}, keywords = {Buoyancy, Eddies, Frontogenesis/frontolysis, Mesoscale processes, Transport, Vertical motion}, doi = {10.1175/jpo-d-20-0035.1}, url = {https://app.dimensions.ai/details/publication/pub.1130879065}, author = {Zhang, Weifeng and McGillicuddy, Dennis J.} } @article {RN198, title = {Year-Round Measurements of the Irminger Current: Variability of a Two-Core Current System Observed in 2014{\textendash}2016}, journal = {Journal of Geophysical Research - Oceans}, volume = {125}, number = {10}, year = {2020}, type = {Journal Article}, abstract = {The Irminger Current (IC), flowing northeastward along the western flank of the Reykjanes Ridge, is an important component in the overturning of the North Atlantic subpolar gyre. A 2-year (2014{\textendash}2016) time series from moored observations shows that the IC consists of two highly variable current cores. A subsampling experiment, using an ocean reanalysis, showed that this current{\textquoteright}s variability is adequately captured by the array. The two current cores contribute nearly equally to the mean volume transport. The total 2-year mean transport was found to be 10.6 Sv with a standard deviation of daily (monthly) values of 9.2 Sv (4.4 Sv) and a standard error of 1.4 Sv. Mean heat and freshwater transport were 0.21 PW and -22.5 mSv, respectively (Sref = 34.92). The volume transport is strongest in spring, and the average over the first year (8.6 Sv) was lower than that of the second year (12.4 Sv), coinciding with an increase in the density gradient over the array in the second year. The variability of the total transport is dominated by variations in the western core, while the warmer, saltier eastern core contributes more to the heat and (negative) freshwater transport. During the two observed winters, which were marked by exceptional deep convection in the central Irminger Sea, mixed layer deepening down to 400 m depth and outcropping of the 27.7 kg m3 isopycnal were observed within the IC.}, doi = {10.1029/2020jc016193}, url = {https://app.dimensions.ai/details/publication/pub.1131253742 https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2020JC016193}, author = {Jong, M. F. and Steur, L. and Fried, N. and Bol, R. and Kritsotalakis, S.} } @article {RN106, title = {Advances in Software-Defined Technologies for Underwater Acoustic Sensor Networks: A Survey}, journal = {Journal of Sensors}, volume = {2019}, year = {2019}, pages = {1-13}, type = {Journal Article}, abstract = {Underwater Acoustic Sensor Networks (UASNs) are an important technical means to explore the ocean realm. However, most UASNs rely on hardware infrastructures with poor flexibility and versatility. The systems typically deploy in a redundant manner, which not only leads to waste but also causes serious signal interference due to multiple noises in designated underwater regions. Software-Defined Networking (SDN) is a novel network paradigm, which provides an innovative approach to improve flexibility and reduce development risks greatly. Although SDN and UASNs are hot topics, there are currently few studies built on both. In this paper, we provide a comprehensive review on the advances in software-defined UASNs. First, we briefly present the background, and then we review the progress of the Software-Defined Radio (SDR), Cognitive Radio (CR), and SDN. Next, we introduce the current issues and potential research areas. Finally, we conclude the paper and present discussions. Based on this work, we hope to inspire more active studies and take a further step on software-defined UASNs with high performances.}, doi = {10.1155/2019/3470390}, url = {https://app.dimensions.ai/details/publication/pub.1111396995 http://downloads.hindawi.com/journals/js/2019/3470390.pdf}, author = {Wang, Jianping and Kong, Dechuan and Chen, Wei and Zhang, Shujing} } @article {RN109, title = {Air-Sea Fluxes With a Focus on Heat and Momentum}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {430}, type = {Journal Article}, abstract = {Turbulent and radiative exchanges of heat between the ocean and atmosphere (hereafter heat fluxes), ocean surface wind stress, and state variables used to estimate them, are Essential Ocean Variables (EOVs) and Essential Climate Variables (ECVs) influencing weather and climate. This paper describes an observational strategy for producing 3-hourly, 25-km (and an aspirational goal of hourly at 10-km) heat flux and wind stress fields over the global, ice-free ocean with breakthrough 1-day random uncertainty of 15 W m{\textendash}2 and a bias of less than 5 W m{\textendash}2. At present this accuracy target is met only for OceanSITES reference station moorings and research vessels (RVs) that follow best practices. To meet these targets globally, in the next decade, satellite-based observations must be optimized for boundary layer measurements of air temperature, humidity, sea surface temperature, and ocean wind stress. In order to tune and validate these satellite measurements, a complementary global in situ flux array, built around an expanded OceanSITES network of time series reference station moorings, is also needed. The array would include 500{\textendash}1000 measurement platforms, including autonomous surface vehicles, moored and drifting buoys, RVs, the existing OceanSITES network of 22 flux sites, and new OceanSITES expanded in 19 key regions. This array would be globally distributed, with 1{\textendash}3 measurement platforms in each nominal 10{\textdegree} by 10{\textdegree} box. These improved moisture and temperature profiles and surface data, if assimilated into Numerical Weather Prediction (NWP) models, would lead to better representation of cloud formation processes, improving state variables and surface radiative and turbulent fluxes from these models. The in situ flux array provides globally distributed measurements and metrics for satellite algorithm development, product validation, and for improving satellite-based, NWP and blended flux products. In addition, some of these flux platforms will also measure direct turbulent fluxes, which can be used to improve algorithms for computation of air-sea exchange of heat and momentum in flux products and models. With these improved air-sea fluxes, the ocean{\textquoteright}s influence on the atmosphere will be better quantified and lead to improved long-term weather forecasts, seasonal-interannual-decadal climate predictions, and regional climate projections.}, keywords = {air-sea heat flux, autonomous surface vehicle, ICOADS, latent heat flux, ocean wind stress, OceanSITES, satellite-based ocean monitoring system, surface radiation}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00430}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00430}, author = {Cronin, Meghan F. and Gentemann, Chelle L. and Edson, James and Ueki, Iwao and Bourassa, Mark and Brown, Shannon and Clayson, Carol Anne and Fairall, Chris W. and Farrar, J. Thomas and Gille, Sarah T. and Gulev, Sergey and Josey, Simon A. and Kato, Seiji and Katsumata, Masaki and Kent, Elizabeth and Krug, Marjolaine and Minnett, Peter J. and Parfitt, Rhys and Pinker, Rachel T. and Stackhouse, Paul W. and Swart, Sebastiaan and Tomita, Hiroyuki and Vandemark, Douglas and Weller, A. Robert and Yoneyama, Kunio and Yu, Lisan and Zhang, Dongxiao} } @article {RN299, title = {AMOC sensitivity to surface buoyancy fluxes: the role of air-sea feedback mechanisms}, journal = {Climate Dynamics}, volume = {53}, number = {7-8}, year = {2019}, pages = {4521-4537}, type = {Journal Article}, doi = {10.1007/s00382-019-04802-4}, url = {https://app.dimensions.ai/details/publication/pub.1115011343 https://link.springer.com/content/pdf/10.1007/s00382-019-04802-4.pdf}, author = {Kostov, Yavor and Johnson, Helen L. and Marshall, David P.} } @article {RN298, title = {Atlantic Meridional Overturning Circulation: Observed Transport and Variability}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {260}, type = {Journal Article}, doi = {10.3389/fmars.2019.00260}, url = {https://app.dimensions.ai/details/publication/pub.1116893735 https://www.frontiersin.org/articles/10.3389/fmars.2019.00260/pdf}, author = {Frajka-Williams, Eleanor and Ansorge, Isabelle J. and Baehr, Johanna and Bryden, Harry L. and Chidichimo, Maria Paz and Cunningham, Stuart A. and Danabasoglu, Gokhan and Dong, Shenfu and Donohue, Kathleen A. and Elipot, Shane and Heimbach, Patrick and Holliday, N. Penny and Hummels, Rebecca and Jackson, Laura C. and Karstensen, Johannes and Lankhorst, Matthias and Le Bras, Isabela A. and Lozier, M. Susan and McDonagh, Elaine L. and Meinen, Christopher S. and Mercier, Herl{\'e} and Moat, Bengamin I. and Perez, Renellys C. and Piecuch, Christopher G. and Rhein, Monika and Srokosz, Meric A. and Trenberth, Kevin E. and Bacon, Sheldon and Forget, Gael and Goni, Gustavo and Kieke, Dagmar and Koelling, Jannes and Lamont, Tarron and McCarthy, Gerard D. and Mertens, Christian and Send, Uwe and Smeed, David A. and Speich, Sabrina and van den Berg, Marcel and Volkov, Denis and Wilson, Chris} } @article {RN66, title = {Axial Seamount: Periodic tidal loading reveals stress dependence of the earthquake size distribution (b value)}, journal = {Earth and Planetary Science Letters}, volume = {512}, year = {2019}, pages = {39-45}, type = {Journal Article}, abstract = {Earthquake size-frequency distributions commonly follow a power law, with the b value often used to quantify the relative proportion of small and large events. Laboratory experi13 ments have found that the b value of microfractures decreases with increasing stress. Stud14 ies have inferred that this relationship also holds for earthquakes based on observations of earthquake b values varying systematically with faulting style, depth, and for subduction zone earthquakes, plate age. However, these studies are limited by small sample sizes de17 spite aggregating events over large regions, which precludes the ability to control for other variables that might also affect earthquake b values such as rock heterogeneity and fault roughness. Our natural experiment in a unique seafloor laboratory on Axial Seamount involves analyzing the size-frequency distribution of \~{}60,000 microearthquakes which delineate a ring-fault system in a 25 km3 21 block of crust that experiences periodic tidal loading of {\textpm}20 kPa. We find that above a threshold stress amplitude, b value is inversely correlated with tidal stress. The earthquake b value varies by \~{}0.09 per kPa change in Coulomb stress. Our results support the potential use of b values to estimate small stress variations in the Earth{\textquoteright}s crust.}, issn = {0012-821X}, doi = {10.1016/j.epsl.2019.01.047}, url = {http://www.sciencedirect.com/science/article/pii/S0012821X19300731}, author = {Tan, Yen Joe and Waldhauser, Felix and Tolstoy, Maya and Wilcock, William S. D.} } @article {RN67, title = {Better Regional Ocean Observing Through Cross-National Cooperation: A Case Study From the Northeast Pacific}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {93}, type = {Journal Article}, abstract = {The ocean knows no political borders. Ocean processes, like summertime wind-driven upwelling, stretch thousands of kilometers along the Northeast Pacific (NEP) coast. This upwelling drives marine ecosystem productivity and is modulated by weather systems and seasonal to interdecadal ocean-atmosphere variability. Major ocean currents in the NEP transport water properties such as heat, fresh water, nutrients, dissolved oxygen, pCO2, and pH close to the shore. The eastward North Pacific Current bifurcates offshore in the NEP, delivering open-ocean signals south into the California Current and north into the Gulf of Alaska. There is a large and growing number of NEP ocean observing elements operated by government agencies, Native American Tribes, First Nations groups, not-for-profit organizations, and private entities. Observing elements include moored and mobile platforms, shipboard repeat cruises, as well as land-based and estuarine stations. A wide range of multidisciplinary ocean sensors are deployed to track, for example, upwelling, downwelling, ocean productivity, harmful algal blooms, ocean acidification and hypoxia, seismic activity and tsunami wave propagation. Data delivery to shore and observatory controls are done through satellite and cell phone communication, and via seafloor cables. Remote sensing from satellites and land-based coastal radar provide broader spatial coverage, while numerical circulation and biogeochemical modeling complement ocean observing efforts. Models span from the deep ocean into the inland Salish Sea and estuaries. NEP ocean observing systems are used to understand regional processes and, together with numerical models, provide ocean forecasts. By sharing data, experiences and lessons learned, the regional ocean observatory is better than the sum of its parts. }, keywords = {coastal oceanography, data delivery, marine eco system, ocean model and observations comparison, Ocean observation}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00093}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00093}, author = {Barth, John A. and Allen, Susan E. and Dever, Edward P. and Dewey, Richard K. and Evans, Wiley and Feely, Richard A. and Fisher, Jennifer L. and Fram, Jonathan P. and Hales, Burke and Ianson, Debby and Jackson, Jennifer and Juniper, Kim and Kawka, Orest and Kelley, Deborah and Klymak, Jody M. and Konovsky, John and Kosro, P. Michael and Kurapov, Alexander and Mayorga, Emilio and MacCready, Parker and Newton, Jan and Perry, R. Ian and Risien, Craig M. and Robert, Marie and Ross, Tetjana and Shearman, R. Kipp and Schumacker, Joe and Siedlecki, Samantha and Trainer, Vera L. and Waterman, Stephanie and Wingard, Christopher E.} } @article {RN70, title = {Calibration of the Normalized Radar Cross Section for Sentinel-1 Wave Mode}, journal = {IEEE Transactions on Geoscience and Remote Sensing}, volume = {57}, number = {3}, year = {2019}, pages = {1514-1522}, type = {Journal Article}, abstract = {Sentinel-1 (S-1) is a two-satellite constellation for continuity of operational synthetic aperture radar (SAR) observations. Wave mode (WV) is the default mode over open ocean for S-1 to monitor global ocean waves and wind field. Therefore, proper radiometric calibration is essential to accurately infer these geophysical quantities. Based on the global data set acquired by S-1A WV, assessment of normalized radar cross section (NRCS) is carried out through comparison with CMOD5.N predictions over open ocean. The calibration accuracy quantified by NRCS residuals between SAR measurements and CMOD5.N demonstrates distinct features for two incidence angles (23.8{\textdegree} and 36.8{\textdegree}). Particularly, NRCS at 23.8{\textdegree} is overall consistent with CMOD5.N, while NRCS at 36.8{\textdegree} displays great deviation. Two recalibration methods are then implemented by examining the backscattering profile over Amazon rain forest and ocean calibration. Both methods show the necessity for recalibration and obtain comparable correction factors for WV1 and WV2, respectively. The NRCS residuals by applying both methods are significantly reduced toward zero. By comparison, ocean calibration is more efficient and practical to implement.}, keywords = {Calibration, Histograms, Oceans, Radiometry, Rain, Synthetic aperture radar, Wind speed}, issn = {0196-2892}, doi = {10.1109/TGRS.2018.2867035}, author = {Li, H. and Mouche, A. and Stopa, J. E. and Chapron, B.} } @article {RN137, title = {Characteristics of an Advective Marine Heatwave in the Middle Atlantic Bight in Early 2017}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {712}, type = {Journal Article}, abstract = {There has been wide interest in Marine Heatwaves and their ecological consequences in recent years. Most analyses have focused on remotely sensed sea surface temperature data due to the temporal and spatial coverage it provides in order to establish the presence and duration of Heatwaves. Using hydrographic data from a variety of sources, we show that an advective Marine Heatwave was initiated by an event in late December of 2016 south of New England, with temperature anomalies measuring up to 6{\textdegree}C and salinity anomalies exceeding 1 PSU. Similar features were observed off of New Jersey in February 2017, and are associated with the Shelfbreak Front migrating from its normal position to mid-shelf or further onshore. Shelf water of 34 PSU was observed just north of Cape Hatteras at the 30 m isobath and across the continental shelf in late April 2017. These observations reveal that the 2017 Marine Heatwave was associated with a strong positive salinity anomaly, that its total duration was approximately 4 months, and its advective path extended roughly 850 km along the length of the continental shelf in the Middle Atlantic Bight. The southward advective velocity implied by the arrival north of Cape Hatteras is consistent with previous estimates of alongshelf velocity for the region. The origin of this Marine Heatwave is likely related to cross-shelf advection driven by the presence of a Warm Core Ring adjacent to the shelfbreak south of New England.}, keywords = {coastal ocean circulation, Heatwave, middle Atlantic bight, shelfbreak front, warm core ring}, doi = {10.3389/fmars.2019.00712}, url = {https://app.dimensions.ai/details/publication/pub.1122782128 https://www.frontiersin.org/articles/10.3389/fmars.2019.00712/pdf}, author = {Gawarkiewicz, Glen and Chen, Ke and Forsyth, Jacob and Bahr, Frank and Mercer, Anna M. and Ellertson, Aubrey and Fratantoni, Paula and Seim, Harvey and Haines, Sara and Han, Lu} } @article {RN148, title = {Constraining Southern Ocean Air-Sea-Ice Fluxes Through Enhanced Observations}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {421}, type = {Journal Article}, abstract = {Air-sea and air-sea-ice fluxes in the Southern Ocean play a critical role in global climate through their impact on the overturning circulation and oceanic heat and carbon uptake. The challenging conditions in the Southern Ocean have led to sparse spatial and temporal coverage of observations. This has led to a {\textquotedblleft}knowledge gap{\textquotedblright} that increases uncertainty in atmosphere and ocean dynamics and boundary-layer thermodynamic processes, impeding improvements in weather and climate models. Improvements will require both process-based research to understand the mechanisms governing air-sea exchange and a significant expansion of the observing system. This will improve flux parameterizations and reduce uncertainty associated with bulk formulae and satellite observations. Improved estimates spanning the full Southern Ocean will need to take advantage of ships, surface moorings, and the growing capabilities of autonomous platforms with robust and miniaturized sensors. A key challenge is to identify observing system sampling requirements. This requires models, Observing System Simulation Experiments (OSSEs), and assessments of the specific spatial-temporal accuracy and resolution required for priority science and assessment of observational uncertainties of the mean state and direct flux measurements. Year-round, high-quality, quasi-continuous in situ flux measurements and observations of extreme events are needed to validate, improve and characterize uncertainties in blended reanalysis products and satellite data as well as to improve parameterizations. Building a robust observing system will require community consensus on observational methodologies, observational priorities, and effective strategies for data management and discovery.}, keywords = {air-sea/air-sea-ice fluxes, climate, ocean{\textendash}atmosphere interaction, ocean{\textendash}ice interaction, Southern Ocean}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00421}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00421}, author = {Swart, Sebastiaan and Gille, Sarah T. and Delille, Bruno and Josey, Simon and Mazloff, Matthew and Newman, Louise and Thompson, Andrew F. and Thomson, Jim and Ward, Brian and du Plessis, Marcel D. and Kent, Elizabeth C. and Girton, James and Gregor, Luke and Heil, Petra and Hyder, Patrick and Pezzi, Luciano Ponzi and de Souza, Ronald Buss and Tamsitt, Veronica and Weller, Robert A. and Zappa, Christopher J.} } @article {RN78, title = {Data Cyber-Infrastructure for End-to-end Science: Experiences from the NSF Ocean Observatories Initiative}, journal = {Computing in Science \& Engineering}, year = {2019}, pages = {1-1}, type = {Journal Article}, abstract = {Large-scale scientific facilities provide a broad community of researchers and educators with open access to instrumentation and data products generated from geographically distributed instruments and sensors. This paper discusses key architectural design, deployment, and operational aspects of a production cyberinfrastructure for the acquisition, processing, and delivery of data from large scientific facilities using experiences from the National Science Foundation{\textquoteright}s Ocean Observatories Initiative. This paper also outlines new models for data delivery and opportunities for insights in a wide range of scientific and engineering domains as the volumes and variety of data from facilities grow.}, keywords = {Cloud computing, Data acquisition, Design methodology, Distributed databases, Information processing, Laboratories, Observatories, Oceanography, US Government}, issn = {1521-9615}, doi = {10.1109/MCSE.2019.2892769}, author = {Rodero, I. and Parashar, M.} } @article {RN112, title = {Developing Autonomous Observing Systems for Micronutrient Trace Metals}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {35}, type = {Journal Article}, abstract = {Trace metal micronutrients are integral to the functioning of marine ecosystems and the export of particulate carbon to the deep ocean. Although much progress has been made in mapping the distributions of metal micronutrients throughout the ocean over the last 30 years, there remain information gaps, most notable during seasonal transitions and in remote regions. The next challenge is to develop in situ sensing technologies necessary to capture the spatial and temporal variabilities of micronutrients characterized with short residence times, highly variable source terms, and sub-nanomolar concentrations in open ocean settings. Such an effort will allow investigation of the biogeochemical processes at the necessary resolution to constrain fluxes, residence times, and the biological and chemical responses to varying metal inputs in a changing ocean. Here, we discuss the current state of the art and analytical challenges associated with metal micronutrient determinations and highlight existing and emerging technologies, namely in situ chemical analyzers, electrochemical sensors, passive preconcentration samplers, and autonomous trace metal clean samplers, which could form the basis of autonomous observing systems for trace metals within the next decade. We suggest that several existing assets can already be deployed in regions of enhanced metal concentrations and argue that, upon further development, a combination of wet chemical analyzers with electrochemical sensors may provide the best compromise between analytical precision, detection limits, metal speciation, and longevity for autonomous open ocean determinations. To meet this goal, resources must be invested to: (1) improve the sensitivity of existing sensors including the development of novel chemical assays; (2) reduce sensor size and power requirements; (3) develop an open-source {\textquotedblleft}Do-It-Yourself{\textquotedblright} infrastructure to facilitate sensor development, uptake by end-users and foster a mechanism by which scientists can rapidly adapt commercially available technologies to in situ applications; and (4) develop a community-led standardized protocol to demonstrate the endurance and comparability of in situ sensor data with established techniques. Such a vision will be best served through ongoing collaborations between trace metal geochemists, analytical chemists, the engineering community, and commercial partners, which will accelerate the delivery of new technologies for in situ metal sensing in the decade following OceanObs{\textquoteright}19.}, keywords = {GEOTRACES, in situ chemical analyzers, in situ sensors, micronutrients, ocean observing time series, OceanObs{\textquoteright}19, trace metals}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00035}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00035}, author = {Grand, Maxime M. and Laes-Huon, Agathe and Fietz, Susanne and Resing, Joseph A. and Obata, Hajime and Luther, George W. and Tagliabue, Alessandro and Achterberg, Eric P. and Middag, Rob and Tovar-S{\'a}nchez, Antonio and Bowie, Andrew R.} } @article {RN73, title = {Development of physical modelling tools in support of risk scenarios: A new framework focused on deep-sea mining}, journal = {Science of The Total Environment}, volume = {650}, year = {2019}, pages = {2294-2306}, type = {Journal Article}, abstract = {Deep-sea mining has gained international interest to provide materials for the worldwide industry. European oceans and, particularly, the Portuguese Exclusive Economic Zone present a recognized number of areas with polymetallic sulphides rich in metals used in high technology developments. A large part of these resources are in the vicinity of sensitive ecosystems, where the mineral extraction can potentially damage deep-ocean life services. In this context, technological research must be intensified, towards the implementation of environmental friendly solutions that mitigate the associated impacts. To reproduce deep-sea dynamics and evaluate the effects of the mining activities, reliable numerical modelling tools should be developed. The present work highlights the usefulness of a new framework for risk and impact assessment based on oceanographic numerical models to support the adoption of good management practices for deep-sea sustainable exploitation. This tool integrates the oceanic circulation model ROMS-Agrif with the semi-Lagrangian model ICHTHYOP, allowing the representation of deep-sea dynamics and particles trajectories considering the sediments physical properties. Numerical simulations for the North Mid-Atlantic Ridge region, revealed the ability of ROMS-Agrif to simulate real deep-sea dynamics through validation with in situ data. Results showed a strong diversity in the particle residence time, with a dependency on their density and size but also on local ocean conditions and bottom topography. The highest distances are obtained for the smaller and less dense particles, although they tend to be confined by bathymetric constrains and deposited in deepest regions. This work highlights the potential of this modelling tool to forecast laden plume trajectories, allowing the definition of risk assessment scenarios for deep-sea mining activities and the implementation of sustainable exploitation plans. Furthermore, the coupling of this numerical solution with models of biota inhabiting deep-sea vent fields into ecosystem models is discussed and outlined as cost-effective tools for the management of these remote ecosystems.}, keywords = {Adaptive management, Biological communities, Deep-sea technologies, Hazard assessment, Numerical modelling, Precautionary principles}, issn = {0048-9697}, doi = {10.1016/j.scitotenv.2018.09.351}, url = {http://www.sciencedirect.com/science/article/pii/S004896971833852X}, author = {Lopes, Carina L. and Bastos, Lu{\'\i}sa and Caetano, Miguel and Martins, Irene and Santos, Miguel M. and Iglesias, Isabel} } @article {RN63, title = {Extreme Variability in Irminger Sea Winter Heat Loss Revealed by Ocean Observatories Initiative Mooring and the ERA5 Reanalysis}, journal = {Geophysical Research Letters}, volume = {46}, number = {1}, year = {2019}, pages = {293-302}, type = {Journal Article}, abstract = {Ground-breaking measurements from the ocean observatories initiative Irminger Sea surface mooring (60{\textdegree}N, 39{\textdegree}30'W) are presented that provide the first in situ characterization of multiwinter surface heat exchange at a high latitude North Atlantic site. They reveal strong variability (December 2014 net heat loss nearly 50\% greater than December 2015) due primarily to variations in frequency of intense short timescale (1{\textendash}3 days) forcing. Combining the observations with the new high resolution European Centre for Medium Range Weather Forecasts Reanalysis 5 (ERA5) atmospheric reanalysis, the main source of multiwinter variability is shown to be changes in the frequency of Greenland tip jets (present on 15 days in December 2014 and 3 days in December 2015) that can result in hourly mean heat loss exceeding 800 W/m2. Furthermore, a new picture for atmospheric mode influence on Irminger Sea heat loss is developed whereby strongly positive North Atlantic Oscillation conditions favor increased losses only when not outweighed by the East Atlantic Pattern. }, issn = {0094-8276}, doi = {10.1029/2018GL080956}, url = {https://doi.org/10.1029/2018GL080956}, author = {Josey, S. A. and de Jong, M. F. and Oltmanns, M. and Moore, G. K. and Weller, R. A.} } @article {RN113, title = {Global Observing Needs in the Deep Ocean}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {241}, type = {Journal Article}, abstract = {The deep ocean below 200 m water depth is the least observed, but largest habitat on our planet by volume and area. Over 150 years of exploration has revealed that this dynamic system provides critical climate regulation, houses a wealth of energy, mineral, and biological resources, and represents a vast repository of biological diversity. A long history of deep-ocean exploration and observation led to the initial concept for the Deep-Ocean Observing Strategy (DOOS), under the auspices of the Global Ocean Observing System (GOOS). Here we discuss the scientific need for globally integrated deep-ocean observing, its status, and the key scientific questions and societal mandates driving observing requirements over the next decade. We consider the Essential Ocean Variables (EOVs) needed to address deep-ocean challenges within the physical, biogeochemical, and biological/ecosystem sciences according to the Framework for Ocean Observing (FOO), and map these onto scientific questions. Opportunities for new and expanded synergies among deep-ocean stakeholders are discussed, including academic-industry partnerships with the oil and gas, mining, cable and fishing industries, the ocean exploration and mapping community, and biodiversity conservation initiatives. Future deep-ocean observing will benefit from the greater integration across traditional disciplines and sectors, achieved through demonstration projects and facilitated reuse and repurposing of existing deep-sea data efforts. We highlight examples of existing and emerging deep-sea methods and technologies, noting key challenges associated with data volume, preservation, standardization, and accessibility. Emerging technologies relevant to deep-ocean sustainability and the blue economy include novel genomics approaches, imaging technologies, and ultra-deep hydrographic measurements. Capacity building will be necessary to integrate capabilities into programs and projects at a global scale. Progress can be facilitated by Open Science and Findable, Accessible, Interoperable, Reusable (FAIR) data principles and converge on agreed to data standards, practices, vocabularies, and registries. We envision expansion of the deep-ocean observing community to embrace the participation of academia, industry, NGOs, national governments, international governmental organizations, and the public at large in order to unlock critical knowledge contained in the deep ocean over coming decades, and to realize the mutual benefits of thoughtful deep-ocean observing for all elements of a sustainable ocean. }, keywords = {biodiversity, blue economy, deep sea, essential ocean variables, Ocean observation, ocean sensors}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00241}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00241}, author = {Levin, Lisa A. and Bett, Brian J. and Gates, Andrew R. and Heimbach, Patrick and Howe, Bruce M. and Janssen, Felix and McCurdy, Andrea and Ruhl, Henry A. and Snelgrove, Paul and Stocks, Karen I. and Bailey, David and Baumann-Pickering, Simone and Beaverson, Chris and Benfield, Mark C. and Booth, David J. and Carreiro-Silva, Marina and Cola{\c c}o, Ana and Ebl{\'e}, Marie C. and Fowler, Ashley M. and Gjerde, Kristina M. and Jones, Daniel O. B. and Katsumata, K. and Kelley, Deborah and Le Bris, Nadine and Leonardi, Alan P. and Lejzerowicz, Franck and Macreadie, Peter I. and McLean, Dianne and Meitz, Fred and Morato, Telmo and Netburn, Amanda and Pawlowski, Jan and Smith, Craig R. and Sun, Song and Uchida, Hiroshi and Vardaro, Michael F. and Venkatesan, R. and Weller, Robert A.} } @article {RN103, title = {Global Perspectives on Observing Ocean Boundary Current Systems}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {423}, type = {Journal Article}, abstract = {Ocean boundary current systems are key components of the climate system, are home to highly productive ecosystems, and have numerous societal impacts. Establishment of a global network of boundary current observing systems is a critical part of ongoing development of the Global Ocean Observing System. The characteristics of boundary current systems are reviewed, focusing on scientific and societal motivations for sustained observing. Techniques currently used to observe boundary current systems are reviewed, followed by a census of the current state of boundary current observing systems globally. The next steps in the development of boundary current observing systems are considered, leading to several specific recommendations.}, keywords = {autonomous underwater gliders, drifters, eastern boundary current systems, moorings, ocean observing systems, remote sensing, time series, western boundary current systems}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00423}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00423}, author = {Todd, Robert E. and Chavez, Francisco P. and Clayton, Sophie and Cravatte, Sophie and Goes, Marlos and Graco, Michelle and Lin, Xiaopei and Sprintall, Janet and Zilberman, Nathalie V. and Archer, Matthew and Ar{\'\i}stegui, Javier and Balmaseda, Magdalena and Bane, John M. and Baringer, Molly O. and Barth, John A. and Beal, Lisa M. and Brandt, Peter and Calil, Paulo H. R. and Campos, Edmo and Centurioni, Luca R. and Chidichimo, Maria Paz and Cirano, Mauro and Cronin, Meghan F. and Curchitser, Enrique N. and Davis, Russ E. and Dengler, Marcus and deYoung, Brad and Dong, Shenfu and Escribano, Ruben and Fassbender, Andrea J. and Fawcett, Sarah E. and Feng, Ming and Goni, Gustavo J. and Gray, Alison R. and Guti{\'e}rrez, Dimitri and Hebert, Dave and Hummels, Rebecca and Ito, Shin-ichi and Krug, Marjorlaine and Lacan, Fran{\c c}ois and Laurindo, Lucas and Lazar, Alban and Lee, Craig M. and Lengaigne, Matthieu and Levine, Naomi M. and Middleton, John and Montes, Ivonne and Muglia, Mike and Nagai, Takeyoshi and Palevsky, Hilary I. and Palter, Jaime B. and Phillips, Helen E. and Piola, Alberto and Plueddemann, Albert J. and Qiu, Bo and Rodrigues, Regina R. and Roughan, Moninya and Rudnick, Daniel L. and Rykaczewski, Ryan R. and Saraceno, Martin and Seim, Harvey and Gupta, Alex Sen and Shannon, Lynne and Sloyan, Bernadette M. and Sutton, Adrienne J. and Thompson, LuAnne and Plas, Anja K. van der and Volkov, Denis and Wilkin, John and Zhang, Dongxiao and Zhang, Linlin} } @article {RN105, title = {Gulf Stream Ring Water Intrusion on the Mid-Atlantic Bight Continental Shelf Break Affects Microbially Driven Carbon Cycling}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {394}, type = {Journal Article}, abstract = {Warm core, anticyclonic rings that spin off from the Gulf Stream circulate through the region directly offshore of the Mid-Atlantic Bight. If a warm core ring reaches the continental shelf break, its warm, highly saline water may subduct under cooler, fresher continental shelf surface water, resulting in subsurface waters at the shelf break and over the upper continental slope with high temperatures and salinities and distinct physical and chemical properties characteristic of Gulf Stream water. Such intruding water may also have microbial communities with distinct functional capacities, which may in turn affect the rate and nature of carbon cycling in this coastal/shelf environment. However, the functional capabilities of microbial communities within ring intrusion waters relative to surrounding continental shelf waters are largely unexplored. We investigated microbial community capacity to initiate organic matter remineralization by measuring hydrolysis of a suite of polysaccharide, peptide, and glucose substrates along a transect oriented across the Mid-Atlantic Bight shelf, shelf break, and upper slope. At the outermost sampling site, warm and salty water derived from a Gulf Stream warm core ring was present in the lower portion of the water column. This water exhibited hydrolytic capacities distinct from other sampling sites, and exhibited lower heterotrophic bacterial productivity overall. Warm core rings adjacent to the Mid-Atlantic Bight shelf have increased in frequency and duration in recent years. As the influence of warm core rings on the continental shelf and slope increases in the future, the rate and nature of organic matter remineralization on the continental shelf may also shift.}, keywords = {carbon cycling, enzymatic activity, heterotrophy, Mid-Atlantic Bight, ring intrusion, warm core ring}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00394}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00394}, author = {Hoarfrost, Adrienne and Balmonte, John Paul and Ghobrial, Sherif and Ziervogel, Kai and Bane, John and Gawarkiewicz, Glen and Arnosti, Carol} } @article {RN108, title = {Integrated Observations of Global Surface Winds, Currents, and Waves: Requirements and Challenges for the Next Decade}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {425}, type = {Journal Article}, abstract = {Ocean surface winds, currents, and waves play a crucial role in exchanges of momentum, energy, heat, freshwater, gases, and other tracers between the ocean, atmosphere, and ice. Despite surface waves being strongly coupled to the upper ocean circulation and the overlying atmosphere, efforts to improve ocean, atmospheric, and wave observations and models have evolved somewhat independently. From an observational point of view, community efforts to bridge this gap have led to proposals for satellite Doppler oceanography mission concepts, which could provide unprecedented measurements of absolute surface velocity and directional wave spectrum at global scales. This paper reviews the present state of observations of surface winds, currents, and waves, and it outlines observational gaps that limit our current understanding of coupled processes that happen at the air-sea-ice interface. A significant challenge for the coming decade of wind, current, and wave observations will come in combining and interpreting measurements from (a) wave-buoys and high-frequency radars in coastal regions, (b) surface drifters and wave-enabled drifters in the open-ocean, marginal ice zones, and wave-current interaction {\textquotedblleft}hot-spots,{\textquotedblright} and (c) simultaneous measurements of absolute surface currents, ocean surface wind vector, and directional wave spectrum from Doppler satellite sensors.}, keywords = {absolute surface velocity, air-sea interactions, Doppler oceanography from space, ocean surface winds, surface waves}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00425}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00425}, author = {Villas B{\^o}as, Ana B. and Ardhuin, Fabrice and Ayet, Alex and Bourassa, Mark A. and Brandt, Peter and Chapron, Betrand and Cornuelle, Bruce D. and Farrar, J. T. and Fewings, Melanie R. and Fox-Kemper, Baylor and Gille, Sarah T. and Gommenginger, Christine and Heimbach, Patrick and Hell, Momme C. and Li, Qing and Mazloff, Matthew R. and Merrifield, Sophia T. and Mouche, Alexis and Rio, Marie H. and Rodriguez, Ernesto and Shutler, Jamie D. and Subramanian, Aneesh C. and Terrill, Eric J. and Tsamados, Michel and Ubelmann, Clement and van Sebille, Erik} } @article {RN140, title = {Interpretation of detections of volcanic activity at Ioto Island obtained from in situ seismometers and remote hydrophones of the International Monitoring System}, journal = {Scientific Reports}, volume = {9}, number = {1}, year = {2019}, pages = {19519}, type = {Journal Article}, abstract = {In-situ seismic observations identified that volcanic activity of Ioto (formerly Iwojima), a volcanic island offshore Japan, increased in early September 2018. Observations of discolored nearshore waters and a splash reported by a local flyover provided evidence for a connection between undersea eruptions and recorded seismic activity. However there remain uncertainties as to when the undersea eruption series commenced and how much of the in-situ seismic activity recorded on the island was associated with volcanic earthquakes versus undersea eruptions. During this period, a large number of underwater acoustic (hydroacoustic) signals were recorded by the Comprehensive Nuclear-Test-Ban Treaty (CTBT) International Monitoring System (IMS) hydroacoustic station HA11, at Wake Island (U.S. Territory), in the northwestern Pacific Ocean with signals with directions of arrival consistent with sources located at Ioto. The analysis presented here interprets signal features of the remote hydroacoustic recordings provided by HA11 in order to attempt to distinguish between volcanic earthquake signals and undersea eruption signals originating from Ioto. Histograms of hydroacoustic events interpreted as originating from Ioto correlate well with the in-situ seismic observations at Ioto in the early stage of volcanic activity. The results presented suggest that around 75\% of the signals detected at HA11 with directions of arrival consistent with Ioto as their origin could be associated with undersea eruptions, supporting the conclusion that the IMS hydroacoustic stations can contribute to volcanic event remote monitoring. }, doi = {10.1038/s41598-019-55918-w}, url = {https://app.dimensions.ai/details/publication/pub.1123547312 https://www.nature.com/articles/s41598-019-55918-w.pdf}, author = {Matsumoto, Hiroyuki and Zampolli, Mario and Haralabus, Georgios and Stanley, Jerry and Mattila, James and Meral {\"O}zel, Nurcan} } @article {RN119, title = {Joint effort among research infrastructures to quantify the impact of plastic debris in the ocean}, journal = {Environmental Research Letters}, volume = {14}, number = {6}, year = {2019}, pages = {065001}, type = {Journal Article}, abstract = {Marine debris is one of the most significant problems facing the marine environment, endangering wildlife, polluting oceans and is an issue which holds global significance. Plastics constitute a large proportion of marine debris, and their persistence can cause a number of negative consequences for biota and the environment, including entanglement and ingestion, which can lead to mortality. Most plastics never biodegrade and instead break down into smaller pieces which are more difficult to monitor and eventually become so small (micro and nanoplastics), that they are challenging to observe or intercept in the ocean. Marine-based Research Infrastructures (RIs) monitor several environmental parameters and are situated around the globe; however, none of these are routinely monitoring marine debris or plastics. Currently, the only infrastructures in place with regard to marine debris are {\textquoteright}physical debris interception infrastructure{\textquoteright} in the form of barriers constructed to prevent marine debris from entering the ocean. Several knowledge gaps and restraints exist within current in situ infrastructure including technological immaturity, diverse methodologies and lack of data harmonisation. Nevertheless, marine RIs could monitor microplastics within the water column on a long-term basis and initial steps towards developing technology are promising.}, issn = {1748-9326}, doi = {10.1088/1748-9326/ab17ed}, url = {http://dx.doi.org/10.1088/1748-9326/ab17ed}, author = {Conchubhair, Diarmuid {\'O} and Fitzhenry, Deirdre and Lusher, Amy and King, Andrew L. and van Emmerik, Tim and Lebreton, Laurent and Ricaurte-Villota, Constanza and Espinosa, Luisa and O{\textquoteright}Rourke, Eleanor} } @article {RN122, title = {A Joint Inversion for Three-dimensional P and S Wave Velocity Structure and Earthquake Locations Beneath Axial Seamount}, journal = {Journal of Geophysical Research: Solid Earth}, volume = {n/a}, number = {n/a}, year = {2019}, type = {Journal Article}, abstract = {Axial Seamount is a prominent volcano located at the intersection of the Juan de Fuca Ridge and the Cobb-Eickelberg hot spot in the northeast Pacific Ocean that has erupted in 1998, 2011, and 2015. The 2015 eruption was recorded by a seven-station seismic network in the southern part of the summit caldera that forms part of the Ocean Observatories Initiative Cabled Array. We utilize a data set of ~3,900 well-recorded earthquakes from January 2015 to February 2017 and a three-dimensional P wave velocity model obtained previously from active source data to conduct a joint inversion for three-dimensional P and S wave velocities and hypocentral parameters. The resulting velocity models are used to relocate >76,000 earthquakes with >=10 arrival times. The velocity models reveal a low-velocity anomaly in the center of the southern caldera at depths less than ~2 km, which corresponds to the top of the magma chamber and is interpreted as a region that is intensely fractured by the cyclical deformation of the caldera. High velocities around the caldera rim are likely due to consolidated undeformed lava flows. Low VP/VS in the southern caldera is consistent with the presence of hydrothermal vapor. Low S wave velocities and high VP/VS in the northern caldera may indicate a region dominated by thin cracks caused by dike injection. The relocated earthquakes delineate outward-dipping ring faults more clearly than previous studies and image a subvertical inward-dipping fault within the network that connects to the east caldera wall and eruptive fissures.}, keywords = {axial seamount, Earthquakes location, Hydrothermal systems, Joint inversion, Tomography, volcano}, issn = {2169-9313}, doi = {10.1029/2019JB017970}, author = {Baillard, Christian and Wilcock, William S. D. and Arnulf, Adrien F. and Tolstoy, Maya and Waldhauser, Felix} } @article {RN117, title = {Large-Signal Stability Analysis of the Undersea Direct Current Power System for Scientific Cabled Seafloor Observatories}, journal = {Applied Sciences}, volume = {9}, number = {15}, year = {2019}, type = {Journal Article}, abstract = {A large number of power electronic converters and long-distance submarine cables are an important part of the undersea direct current (DC) power system of the scientific cabled seafloor observatories (CSOs). However, the constant power load (CPL) characteristics of the converters and the distributed parameter characteristics of long-distance submarine cables greatly affect the stability of the CSO DC power system. This paper analyzes the large-signal stability of the CSO DC power system, and the equivalent circuits of long-distance submarine cables are established by theoretical analysis and computer simulation. A simplified computer simulation model and an equivalent experimental prototype model of a single-node CSO DC power system was built in the laboratory to study this issue. The mixed potential function method is used to analyze the large-signal stability of the CSO DC power system, and the large-signal stability criterion is obtained theoretically. The validity of the large-signal stability criterion is proved by simulations and experiments. The conclusion is that reducing the inductance of the submarine cable, increasing the capacitance of the submarine cable, increasing the output voltage of the shore station power feeding equipment (PFE) or reducing the power consumption of the undersea station, are beneficial to improve the large-signal stability of the CSO DC power system.}, keywords = {cabled seafloor observatories, direct current power systems, large-signal stability, mixed potential function}, issn = {2076-3417}, doi = {10.3390/app9153149}, author = {Jiang, Yamei and Lyu, Feng} } @article {RN76, title = {Lessons Learned From the United States Ocean Observatories Initiative}, journal = {Frontiers in Marine Science}, volume = {5}, year = {2019}, pages = {494}, type = {Journal Article}, abstract = {The Ocean Observatories Initiative (OOI) is a United States National Science Foundation-funded major research facility that provides continuous observations of the ocean and seafloor from coastal and open ocean locations in the Atlantic and Pacific. Multiple cycles of OOI infrastructure deployment, recovery, and refurbishment have occurred since operations began in 2014. This heterogeneous ocean observing infrastructure with multidisciplinary sampling in important but challenging locations has provided new scientific and engineering insights into the operation of a sustained ocean observing system. This paper summarizes the challenges, successes, and failures experienced to date and shares recommendations on best practices that will be of benefit to the global ocean observing community.}, keywords = {best practices, equipment testing, lessons learned, ocean observing, technology development}, issn = {2296-7745}, doi = {10.3389/fmars.2018.00494}, url = {https://www.frontiersin.org/article/10.3389/fmars.2018.00494}, author = {Smith, Leslie M. and Yarincik, Kristen and Vaccari, Liana and Kaplan, Maxwell B. and Barth, John A. and Cram, Geoffrey S. and Fram, Jonathan P. and Harrington, Michael and Kawka, Orest E. and Kelley, Deborah S. and Matthias, Paul and Newhall, Kristopher and Palanza, Matthew and Plueddemann, Albert J. and Vardaro, Michael F. and White, Sheri N. and Weller, Robert Andrew} } @article {RN68, title = {Location of Seismic {\textquotedblleft}Hum{\textquotedblright} Sources Following Storms in the North Pacific Ocean}, journal = {Geochemistry, Geophysics, Geosystems}, year = {2019}, type = {Journal Article}, abstract = {We investigate the spatially and temporally varying distributions of sources of the Earth{\textquoteright}s low-frequency seismic hum at high space-time resolution during a seismically quiet 7-day period in December 2015, when two large storms with different reaches propagate across the North Pacific Ocean. We integrate information from a variety of data from ocean wave height, infragravity wave prediction model, and broadband seismic data. We analyze seismic data to understand the seismic hum better: power spectral density at stations for detection and location of sources using array beamforming and backprojection methods, with a ~3-hr temporal and ~5{\textdegree} spatial resolution. For storms propagating west to east across the northern Pacific hitting the west coast of North America broadscale, we show that the distribution of hum sources is consistent with a model of seismic energy generated via infragravity waves, produced near the impact location of the storm, and propagating along the coast as well as toward the open ocean. The generation of seismic hum depends strongly on the reach of the storm and is very weak for a storm with more northerly propagation toward Alaska. At shorter periods (e.g., ~70 s), the seismic hum is generated in a narrow band that follows the coast, reaching progressively further to the north, while at longer periods (e.g. 150 s), it covers a broader area reaching far into the deep ocean. It may thus be possible to predict the distribution of the strongest {\textquotedblleft}hum{\textquotedblright} sources, to first order, from the knowledge of the direction of propagation and strength of northern Pacific storms. }, issn = {1525-2027}, doi = {10.1029/2018GC008112}, url = {https://doi.org/10.1029/2018GC008112}, author = {Maurya, Satish and Taira, Taka{\textquoteright}aki and Romanowicz, Barbara} } @article {RN217, title = {The mechanism of tidal triggering of earthquakes at mid-ocean ridges}, journal = {Nature Communications}, volume = {10}, number = {1}, year = {2019}, pages = {2526}, type = {Journal Article}, abstract = {The strong tidal triggering of mid-ocean ridge earthquakes has remained unexplained because the earthquakes occur preferentially during low tide, when normal faulting earthquakes should be inhibited. Using Axial Volcano on the Juan de Fuca ridge as an example, we show that the axial magma chamber inflates/deflates in response to tidal stresses, producing Coulomb stresses on the faults that are opposite in sign to those produced by the tides. When the magma chamber{\textquoteright}s bulk modulus is sufficiently low, the phase of tidal triggering is inverted. We find that the stress dependence of seismicity rate conforms to triggering theory over the entire tidal stress range. There is no triggering stress threshold and stress shadowing is just a continuous function of stress decrease. We find the viscous friction parameter A to be an order of magnitude smaller than laboratory measurements. The high tidal sensitivity at Axial Volcano results from the shallow earthquake depths.}, issn = {2041-1723}, doi = {10.1038/s41467-019-10605-2}, url = {https://doi.org/10.1038/s41467-019-10605-2}, author = {Scholz, Christopher H. and Tan, Yen Joe and Albino, Fabien} } @article {RN114, title = {A Numerical Model Analysis of the Mean and Seasonal Nitrogen Budget on the Northeast U.S. Shelf}, journal = {Journal of Geophysical Research: Oceans}, volume = {124}, number = {5}, year = {2019}, pages = {2969-2991}, type = {Journal Article}, abstract = {The supply of nitrogen is a primary limiting factor for the productivity of the Northeast United States (NEUS) continental shelf. In this study, a 12-year (1996{\textendash}2007) retrospective physical-biogeochemical simulation over the Northwest Atlantic was used to analyze the mean and seasonal NEUS shelf nitrogen budget, including the connections between shelf subregions: the Gulf of Maine/Georges Bank (GoM/GB), and the Mid-Atlantic Bight (MAB). The model captures the primary mean and seasonal patterns of shelf circulation, nitrate, and plankton dynamics. Results confirm aspects of previous nitrogen budget analyses, including the dominance of offshore nitrogen influxes into the GoM/GB and the prominent role of riverine influxes and sedimentary denitrification in the MAB. However, detailed spatiotemporal analysis of nitrogen fluxes highlights the importance of dispersed inflows of shallow to intermediate depth waters (0{\textendash}75 m), which can at times exceed the deep nitrogen influx emphasized in previous studies. A seasonal analysis shows a pronounced shift from the net import of nitrogen to the GoM/GB region during late fall and winter, to the net export of nitrogen from the region in the spring and early summer. The MAB, in contrast, consistently exports nitrogen to offshore waters. The prominence of the 0-75m nitrogen supply has implications for the roles of Labrador Slope Water and Atlantic Temperate Slope Water on the NEUS ecosystems, as Atlantic Temperate Slope Water has greater nitrate concentrations than Labrador Slope Water at depth but often less at the surface. Results suggest the need for further study of shallow to intermediate depth inflows beyond those from the Scotian Shelf, particularly during the fall/winter of net nitrogen inflow.}, issn = {2169-9275}, doi = {10.1029/2018JC014308}, url = {https://doi.org/10.1029/2018JC014308}, author = {Zhang, Shuwen and Stock, Charles A. and Curchitser, Enrique N. and Dussin, Raphael} } @article {RN100, title = {An Observed Regime Shift in the Formation of Warm Core Rings from the Gulf Stream}, journal = {Scientific Reports}, volume = {9}, number = {1}, year = {2019}, pages = {12319}, type = {Journal Article}, abstract = {We present observational evidence that a significant regime change occurred around the year 2000 in the formation of Warm Core Rings (WCRs) from the Gulf Stream (GS) between 75{\textdegree} and 55{\textdegree}W. The dataset for this study is a set of synoptic oceanographic charts available over the thirty-eight-year period of 1980{\textendash}2017. The upward regime change shows an increase to 33 WCRs per year during 2000{\textendash}2017 from an average of 18 WCRs during 1980 to 1999. A seasonal analysis confirms May-June-July as the peak time for WCR births in agreement with earlier studies. The westernmost region (75{\textdegree}-70{\textdegree}W) is least ring-productive, while the region from 65{\textdegree}W to 60{\textdegree}W is most productive. This regime shift around 2000 is detected in WCR formation for all of the four 5-degree wide sub-regions and the whole region (75{\textdegree}-55{\textdegree}W). This might be related to a reduction of the deformation radius for ring formation, allowing unstable meanders to shed more frequent rings in recent years. A number of possible factors resulting in such a regime shift related to the possible changes in reduced gravity, instability, transport of the GS, large-scale changes in the wind system and atmospheric fluxes are outlined, which suggest new research directions. The increase in WCRs has likely had an impact on the marine ecosystem since 2000, a topic worthy for future studies.}, issn = {2045-2322}, doi = {10.1038/s41598-019-48661-9}, url = {https://doi.org/10.1038/s41598-019-48661-9}, author = {Gangopadhyay, Avijit and Gawarkiewicz, Glen and Silva, E. Nishchitha S. and Monim, M. and Clark, Jenifer} } @article {RN297, title = {Observing System Evaluation Based on Ocean Data Assimilation and Prediction Systems: On-Going Challenges and a Future Vision for Designing and Supporting Ocean Observational Networks}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {417}, type = {Journal Article}, doi = {10.3389/fmars.2019.00417}, url = {https://app.dimensions.ai/details/publication/pub.1119946952 https://www.frontiersin.org/articles/10.3389/fmars.2019.00417/pdf}, author = {Fujii, Yosuke and R{\'e}my, Elisabeth and Zuo, Hao and Oke, Peter and Halliwell, George and Gasparin, Florent and Benkiran, Mounir and Loose, Nora and Cummings, James and Xie, Jiping and Xue, Yan and Masuda, Shuhei and Smith, Gregory C. and Balmaseda, Magdalena and Germineaud, Cyril and Lea, Daniel J. and Larnicol, Gilles and Bertino, Laurent and Bonaduce, Antonio and Brasseur, Pierre and Donlon, Craig and Heimbach, Patrick and Kim, YoungHo and Kourafalou, Villy and Le Traon, Pierre-Yves and Martin, Matthew and Paturi, Shastri and Tranchant, Benoit and Usui, Norihisa} } @article {RN121, title = {Ocean Observatories as a Tool to Advance Gas Hydrate Research}, journal = {Earth and Space Science}, year = {2019}, type = {Journal Article}, abstract = {Since 2009, unprecedented comprehensive long-term gas hydrate observations have become available from Ocean Networks Canada{\textquoteright}s NEPTUNE cabled ocean observatory at the northern Cascadia margin. Several experiments demonstrate the scientific importance of permanent power and Internet connectivity to the ocean floor as they have advanced the field of gas hydrate related research. One example is the cabled crawler Wally at Barkley Canyon, enabling live in situ exploration of the hydrate mounds and its associated benthic communities through the crawler{\textquoteright}s mobility and permanent accessibility throughout the year. Another example is a bubble-imaging sonar at Clayoquot Slope, revealing the strong relationship between ebullition of natural gas and tidal pressure, without apparent correlation to earthquakes, storms, or temperature fluctuations, in year-long continuous recordings. Finally, regular observatory maintenance cruises allow additional science sampling including echo-sounder surveys to extend the observatory footprint. Long-term trends in the data are not yet apparent but can also become evident from continuous measurements, as ocean observatories such as NEPTUNE are built for a 25-year lifetime, and expansion of the observatory networks makes these findings comparable and testable.}, doi = {10.1029/2019EA000762}, author = {Scherwath, M. and Thomsen, L. and Riedel, M. and Romer, M. and Chatzievangelou, D. and Schwendner, J. and Duda, A. and Heesemann, M.} } @article {RN69, title = {The Ocean Observatories Initiative}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {74}, type = {Journal Article}, abstract = {The Ocean Observatories Initiative (OOI) is an integrated network that enables scientific investigation of interlinked physical, chemical, biological and geological processes throughout the global ocean. With near real-time data delivery via a common Cyberinfrastructure, the OOI instruments two contrasting ocean systems at three scales. The Regional Cabled Array instruments a tectonic plate and overlying ocean in the northeast Pacific, providing a permanent electro-optical cable connecting multiple seafloor nodes that provide high power and bandwidth to seafloor sensors and moorings with instrumented wire crawlers, all with speed-of-light interactive capabilities. Coastal arrays include the Pioneer Array, a relocatable system currently quantifying the New England shelf-break front, and the Endurance Array, a fixed system off Washington and Oregon with connections to the Regional Cabled Array. The Global Arrays host deep-ocean moorings and gliders to provide interdisciplinary measurements of the water column, mesoscale variability, and air-sea fluxes at critical high latitude locations. The OOI has unique aspects relevant to the international ocean observing community. The OOI uses common sensor types, verification protocols, and data formats across multiple platform types in diverse oceanographic regimes. OOI observing is sustained, with initial deployment in 2013 and 25 years of operation planned. The OOI is distributed among sites selected for scientific relevance based on community input and linked by important oceanographic processes. Scientific highlights include real-time observations of a submarine volcanic eruption, time-series observations of methane bubble plumes from Southern Hydrate Ridge off Oregon, observations of anomalous low-salinity pulses off Oregon, discovery of new mechanisms for intrusions of the Gulf Stream onto the shelf in the Middle Atlantic Bight, documentation of deep winter convection in the Irminger Sea, and observations of extreme surface forcing at the most southerly surface mooring in the world ocean. }, keywords = {biological oceanography, chemical oceanography, marine geology and geophysics, ocean engineering, ocean observing, physical oceanography}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00074}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00074}, author = {Trowbridge, John and Weller, Robert and Kelley, Deborah and Dever, Edward and Plueddemann, Albert and Barth, John A. and Kawka, Orest} } @article {RN216, title = {Ocean Time Series Observations of Changing Marine Ecosystems: An Era of Integration, Synthesis, and Societal Applications}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {393}, type = {Journal Article}, abstract = {Sustained ocean time series are critical for characterizing marine ecosystem shifts in a time of accelerating, and at times unpredictable, changes. They represent the only means to distinguish between natural and anthropogenic forcings, and are the best tools to explore causal links and implications for human communities that depend on ocean resources. Since the inception of sustained ocean observations, ocean time series have withstood many challenges, most prominently availability of uninterrupted funding and retention of trained personnel. This OceanObs{\textquoteright}19 review article provides an overarching vision for sustained ocean time series observations for the next decade, focusing on the growing challenges of maintaining sustained ocean time series, including ship-based and autonomous coastal and open-ocean platforms, as well as remote sensing. In addition to increased diversification of funding sources to include the private sector, NGOs, and other groups, more effective engagement of stakeholders and other end-users will be critical to ensure the sustainability of ocean time series programs. Building a cohesive international time series network will require dedicated capacity to coordinate across observing programs and leverage existing infrastructure and platforms of opportunity. This review article outlines near-term observing priorities and technology needs; explores potential mechanisms to broaden ocean time series data applications and end-user communities; and describes current tools and future requirements for managing increasingly complex multi-platform data streams and developing synthesis products that support science and society. The actionable recommendations outlined herein ultimately form the basis for a robust, sustainable, fit-for-purpose time series network that will foster a predictive understanding of changing ocean systems for the benefit of society.}, keywords = {climate, end-users, marine ecosystems, ocean time series, sustained observations, synthesis}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00393}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00393}, author = {Benway, Heather M. and Lorenzoni, Laura and White, Angelicque E. and Fiedler, Bj{\"o}rn and Levine, Naomi M. and Nicholson, David P. and DeGrandpre, Michael D. and Sosik, Heidi M. and Church, Matthew J. and O{\textquoteright}Brien, Todd D. and Leinen, Margaret and Weller, Robert A. and Karl, David M. and Henson, Stephanie A. and Letelier, Ricardo M.} } @article {RN83, title = {Open science, reproducibility, and transparency in ecology}, journal = {Ecological Applications}, volume = {29}, number = {1}, year = {2019}, pages = {e01822}, type = {Journal Article}, abstract = {Reproducibility is a key tenet of the scientific process that dictates the reliability and generality of results and methods. The complexities of ecological observations and data present novel challenges in satisfying needs for reproducibility and also transparency. Ecological systems are dynamic and heterogeneous, interacting with numerous factors that sculpt natural history and that investigators cannot completely control. Observations may be highly dependent on spatial and temporal context, making them very difficult to reproduce, but computational reproducibility can still be achieved. Computational reproducibility often refers to the ability to produce equivalent analytical outcomes from the same data set using the same code and software as the original study. When coded workflows are shared, authors and editors provide transparency for readers and allow other researchers to build directly and efficiently on primary work. These qualities may be especially important in ecological applications that have important or controversial implications for science, management, and policy. Expectations for computational reproducibility and transparency are shifting rapidly in the sciences. In this work, we highlight many of the unique challenges for ecology along with practical guidelines for reproducibility and transparency, as ecologists continue to participate in the stewardship of critical environmental information and ensure that research methods demonstrate integrity. Ecologists have long faced a novel challenge not routinely encountered in less field-oriented sciences: repeated testing is fundamental to the scientific method (Popper 1934) yet it is impossible to perfectly repeat observational studies of the natural world (Vanderbilt and Blankman 2017). This issue is timely as scientists across disciplines increasingly recognize the challenges of reproducing published results, and the threats that irreproducible results pose to the scientific process (Munafo et al. 2017). Reproducibility and transparency issues are particularly important for scientists engaged in actionable science and ecological applications; this work often feeds back rapidly and directly on biota, ecosystems, and people who have stakes in conservation or management outcomes, in turn affecting perceptions about the integrity of our field. For ecologists engaged in observational and field-based studies, data are often highly dependent on the spatial and temporal context of the specific system (Huang 2014, Schnitzer and Carson 2016, LaDeau et al. 2017, Peters and Okin 2017). The weather does not recycle itself. Gradual changes over time, regime shifts, and legacies of past events can greatly influence how natural systems work, as well as our perceptions about how they work (Magnuson 1990). With this complexity, ecology has relied on deep understanding of natural history as a source of ideas about pattern and process (Anderson 2017), often through long periods of intensive observation that could be argued as irreproducible. Even if we could bring back our predecessors, many of their study systems now bear little resemblance to earlier states. Such irregularities in the natural world can torment experimental ecologists. Repeated or replicated sequences in time are elusive and, likewise, neighboring populations, communities, or ecosystems observed within the same day or year can still differ in important ways that affect the outcomes of studies. Thus, while broad guidelines for reproducible research in the sciences are available (Sandve et al. 2013), ecologists face novel challenges that complicate adoption of such general practices. These challenges are linked to the heterogeneity of the systems we study, as well as the approaches and information we use. Strategies that increase the reproducibility of ecological studies are being pursued (Milcu et al. 2018) and it is important that ecologists address these issues if we are to continue serving a critical role in understanding the complex dynamics of the biosphere in the Anthropocene. }, issn = {1051-0761}, doi = {10.1002/eap.1822}, url = {https://doi.org/10.1002/eap.1822}, author = {Powers, Stephen M. and Hampton, Stephanie E.} } @article {RN125, title = {Optimizing Sensor Configurations for the Detection of Slow-Slip Earthquakes in Seafloor Pressure Records, Using the Cascadia Subduction Zone as a Case Study}, journal = {Journal of Geophysical Research-Solid Earth}, year = {2019}, type = {Journal Article}, abstract = {We present seafloor pressure records from the Cascadia Subduction Zone, alongside oceanographic and geophysical models, to evaluate the spatial uniformity of bottom pressure and optimize the geometry of sensor networks for resolving offshore slow-slip transients. Seafloor pressure records from 2011 to 2015 show that signal amplitudes are depth-dependent, with tidally filtered and detrended root-mean-squares of <2 cm on the abyssal plain and >6 cm on the continental shelf. This is consistent with bottom pressure predictions from circulation models and comparable to deformation amplitudes from offshore slow slip observed in other subduction zones. We show that the oceanographic component of seafloor pressure can be reduced to <=1-cm root-mean-square by differencing against a reference record from a similar depth, under restrictions that vary with depth. Instruments at 100{\textendash}250 m require depths matched within 10 m at separations of <100 km, while locations deeper than 1,400 m are broadly comparable over separations of at least 300 km. Despite the significant noise reduction from this method, no slow slip was identified in the dataset, possibly due to poor spatiotemporal instrument coverage, nonideal deployment geometry, and limited depth-matched instruments. We use forward predictions of deformation from elastic half-space models and hindcast pressure from circulation models to generate synthetic slow-slip observational records and show that a range of slip scenarios produce resolvable signals under depth-matched differencing. For future detection of offshore slow slip in Cascadia, we recommend a geometry in which instruments are deployed along isobaths to optimize corrections for oceanographic signals.}, issn = {2169-9313}, doi = {10.1029/2019JB018053}, author = {Fredrickson, E. K. and Wilcock, W. S. D. and Schmidt, D. A. and MacCready, P. and Roland, E. and Kurapov, A. L. and Zumberge, M. A. and Sasagawa, G. S.} } @article {RN77, title = {Partnering with Fishing Fleets to Monitor Ocean Conditions}, journal = {Annual Review of Marine Science}, volume = {11}, number = {1}, year = {2019}, pages = {391-411}, type = {Journal Article}, abstract = {Engaging ocean users, including fishing fleets, in oceanographic and ecological research is a valuable method for collecting high-quality data, improving cost efficiency, and increasing societal appreciation for scientific research. As research partners, fishing fleets provide broad access to and knowledge of the ocean, and fishers are highly motivated to use the data collected to better understand the ecosystems in which they harvest. Here, we discuss recent trends in collaborative research that have increased the capacity of and access to scientific data collection. We also describe common elements of successful collaborative research programs, including definition of a scientific problem and goals, choice of technology, data collection and sampling design, data management and dissemination, and data analysis and communication. Finally, we review four case studies that demonstrate the general principles of effective collaborative research as well as the utility of citizen-collected data for academic research and fisheries management. We also discuss the challenge of funding, particularly as it relates to maintaining collaborative research programs in the long term. We conclude with a discussion of likely future trends. Ultimately, we predict that collaborative research will continue to grow in importance as climate change increasingly impacts ocean ecosystems, commercial fisheries, and the global food supply.}, keywords = {citizen science, collaborative research, hydrography, ocean monitoring}, issn = {1941-1405}, doi = {10.1146/annurev-marine-010318-095201}, url = {https://doi.org/10.1146/annurev-marine-010318-095201}, author = {Gawarkiewicz, Glen and Malek Mercer, Anna} } @article {RN111, title = {Polar Ocean Observations: A Critical Gap in the Observing System and Its Effect on Environmental Predictions From Hours to a Season}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {429}, type = {Journal Article}, abstract = {There is a growing need for operational oceanographic predictions in both the Arctic and Antarctic polar regions. In the former, this is driven by a declining ice cover accompanied by an increase in maritime traffic and exploitation of marine resources. Oceanographic predictions in the Antarctic are also important, both to support Antarctic operations and also to help elucidate processes governing sea ice and ice shelf stability. However, a significant gap exists in the ocean observing system in polar regions, compared to most areas of the global ocean, hindering the reliability of ocean and sea ice forecasts. This gap can also be seen from the spread in ocean and sea ice reanalyses for polar regions which provide an estimate of their uncertainty. The reduced reliability of polar predictions may affect the quality of various applications including search and rescue, coupling with numerical weather and seasonal predictions, historical reconstructions (reanalysis), aquaculture and environmental management including environmental emergency response. Here, we outline the status of existing near-real time ocean observational efforts in polar regions, discuss gaps, and explore perspectives for the future. Specific recommendations include a renewed call for open access to data, especially real-time data, as a critical capability for improved sea ice and weather forecasting and other environmental prediction needs. Dedicated efforts are also needed to make use of additional observations made as part of the Year of Polar Prediction (YOPP; 2017{\textendash}2019) to inform optimal observing system design. To provide a polar extension to the Argo network, it is recommended that a network of ice-borne sea ice and upper-ocean observing buoys be deployed and supported operationally in ice-covered areas together with autonomous profiling floats and gliders (potentially with ice detection capability) in seasonally ice covered seas. Finally, additional efforts to better measure and parameterize surface exchanges in polar regions are much needed to improve coupled environmental prediction.}, keywords = {air-sea-ice fluxes, forecasting, ocean data assimilation, ocean modeling, operational oceanography, polar observations, sea ice, YOPP}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00429}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00429}, author = {Smith, Gregory C. and Allard, Richard and Babin, Marcel and Bertino, Laurent and Chevallier, Matthieu and Corlett, Gary and Crout, Julia and Davidson, Fraser and Delille, Bruno and Gille, Sarah T. and Hebert, David and Hyder, Patrick and Intrieri, Janet and Lagunas, Jos{\'e} and Larnicol, Gilles and Kaminski, Thomas and Kater, Belinda and Kauker, Frank and Marec, Claudie and Mazloff, Matthew and Metzger, E. Joseph and Mordy, Calvin and O{\textquoteright}Carroll, Anne and Olsen, Steffen M. and Phelps, Michael and Posey, Pamela and Prandi, Pierre and Rehm, Eric and Reid, Phillip and Rigor, Ignatius and Sandven, Stein and Shupe, Matthew and Swart, Sebastiaan and Smedstad, Ole Martin and Solomon, Amy and Storto, Andrea and Thibaut, Pierre and Toole, John and Wood, Kevin and Xie, Jiping and Yang, Qinghua and Group, the Wwrp P. P. P. Steering} } @article {RN72, title = {Posteruption Enhancement of Hydrothermal Activity: A 33-Year, Multieruption Time Series at Axial Seamount (Juan de Fuca Ridge)}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {20}, number = {2}, year = {2019}, pages = {814-828}, type = {Journal Article}, abstract = {Mid-ocean ridge eruptions, initiating or revitalizing hydrothermal discharge and disrupting seafloor ecosystems, occur regularly as a consequence of plate spreading. Evaluating their impact on long-term hydrothermal discharge requires information on the scale and duration of any posteruption enhancement. Here we describe a unique hydrothermal plume time series of annual (or more frequent) observations at Axial Seamount vent fields from 1985 through 2017, missing only 7 years. Axial, a hot spot volcano astride the Juan de Fuca Ridge, experienced eruptions in 1998, 2011, and 2015. In 1998 and 2011 lava flooded the SE caldera and south rift zone, but in 2015 most lava was extruded in a series of flows extending ~20 km down the north rift zone. Response cruises occurred within 18 days (1998) to about 4 months, followed by regular posteruption observations. All 30 cruises measured plume rise height (a proxy for heat flux) and turbidity (indicative of chemical changes in vent discharge) at several vent sites, yielding an integrated view of vent field activity. Venting in the SE caldera area persisted throughout the time series, consistent with the imaged location of the shallowest portion of the melt-rich magma reservoir. Eruptions produced substantial and diagnostic increases in plume rise and turbidity, and posteruption enhancements lasted 2{\textendash}5 years, totaling ~10 years over the course of the time series. Estimates of the relative heat flux indicate a sixfold increase during eruption-enhanced periods, implying that generalizations about mid-ocean ridge hydrothermal fluxes may be underestimates if based on non{\textendash}eruption-enhanced hydrothermal activity alone.}, issn = {1525-2027}, doi = {10.1029/2018GC007802}, url = {https://doi.org/10.1029/2018GC007802}, author = {Baker, Edward T. and Walker, Sharon L. and Chadwick Jr, William W. and Butterfield, David A. and Buck, Nathaniel J. and Resing, Joseph A.} } @article {RN95, title = {Scientific considerations for acidification monitoring in the U.S. Mid-Atlantic Region}, journal = {Estuarine Coastal and Shelf Science}, year = {2019}, pages = {106189}, type = {Journal Article}, abstract = {Coastal and ocean acidification has the potential to cause significant environmental and societal impacts. Monitoring carbonate chemistry parameters over spatial and temporal scales is challenging, especially with limited resources. A lack of monitoring data can lead to a limited understanding of real-world conditions. Without such data, robust experimental and model design is challenging, and the identification and understanding of episodic acidification events is nearly impossible. We present considerations for resource managers, academia, and industry professionals who are currently developing acidification monitoring programs in the Mid-Atlantic region. We highlight the following considerations for deliberation: 1) leverage existing infrastructure to include multiple carbonate chemistry parameters as well as other water quality measurements, 2) direct monitoring efforts in subsurface waters rather than limiting monitoring to surface waters, 3) identify the best available sensor technology for long-term, in-situ monitoring, 4) monitor across a salinity gradient to account for the complexity of estuarine, coastal, and ocean environments, and identify potential areas of enhanced vulnerability, 5) increase sampling frequency to capture variability, 6) consider other drivers (e.g., freshwater discharge, nutrients, physiochemical parameters) that may affect acidification, and 7) conduct or continue monitoring in specific ecological and general regions that may have enhanced vulnerability. Through the incorporation of these considerations, individual monitoring programs can more efficiently and effectively leverage resources and build partnerships for a more comprehensive data collection in the region. While these considerations focus on the Mid-Atlantic region), similar strategies can be used to leverage resources in other locations. }, doi = {10.1016/j.ecss.2019.04.023}, url = {https://app.dimensions.ai/details/publication/pub.1113786544 https://doi.org/10.1016/j.ecss.2019.04.023}, author = {Goldsmith, Kaitlin A. and Lau, Sherilyn and Poach, Matthew E. and Sakowicz, Gregg P. and Trice, T. Mark and Ono, C. Ryan and Nye, Janet and Shadwick, Elizabeth H. and StLaurent, Kari A. and Saba, Grace K.} } @article {RN71, title = {A sea change in our view of overturning in the subpolar North Atlantic}, journal = {Science}, volume = {363}, number = {6426}, year = {2019}, pages = {516}, type = {Journal Article}, abstract = {To provide an observational basis for the Intergovernmental Panel on Climate Change projections of a slowing Atlantic meridional overturning circulation (MOC) in the 21st century, the Overturning in the Subpolar North Atlantic Program (OSNAP) observing system was launched in the summer of 2014. The first 21-month record reveals a highly variable overturning circulation responsible for the majority of the heat and freshwater transport across the OSNAP line. In a departure from the prevailing view that changes in deep water formation in the Labrador Sea dominate MOC variability, these results suggest that the conversion of warm, salty, shallow Atlantic waters into colder, fresher, deep waters that move southward in the Irminger and Iceland basins is largely responsible for overturning and its variability in the subpolar basin.}, doi = {10.1126/science.aau6592}, url = {http://science.sciencemag.org/content/363/6426/516.abstract}, author = {Lozier, M. S. and Li, F. and Bacon, S. and Bahr, F. and Bower, A. S. and Cunningham, S. A. and de Jong, M. F. and de Steur, L. and deYoung, B. and Fischer, J. and Gary, S. F. and Greenan, B. J. W. and Holliday, N. P. and Houk, A. and Houpert, L. and Inall, M. E. and Johns, W. E. and Johnson, H. L. and Johnson, C. and Karstensen, J. and Koman, G. and Le Bras, I. A. and Lin, X. and Mackay, N. and Marshall, D. P. and Mercier, H. and Oltmanns, M. and Pickart, R. S. and Ramsey, A. L. and Rayner, D. and Straneo, F. and Thierry, V. and Torres, D. J. and Williams, R. G. and Wilson, C. and Yang, J. and Yashayaev, I. and Zhao, J.} } @article {RN96, title = {A Seabed Real-Time Sensing System for In-Situ Long-Term Multi-Parameter Observation Applications}, journal = {Sensors}, volume = {19}, number = {5}, year = {2019}, pages = {1255}, type = {Journal Article}, abstract = {Aiming at the real-time observation requirements in marine science and ocean engineering, based on underwater acoustic communication and satellite communication technology, a seabed real-time sensing system for in-situ long-term multi-parameter observation applications (SRSS/ILMO) is proposed. It consists of a seabed observation system, a sea surface relay transmission buoy, and a remote monitoring system. The system communication link is implemented by underwater acoustic communication and satellite communication. The seabed observation system adopts the {\textquotedblleft}ARM + FPGA{\textquotedblright} architecture to meet the low power consumption, scalability, and versatility design requirements. As a long-term unattended system, a two-stage anti-crash mechanism, an automatic system fault isolation design, dual-medium data storage, and improved Modbus protocol are adopted to meet the system reliability requirements. Through the remote monitoring system, users can configure the system working mode, sensor parameters and acquire observation data on demand. The seabed observation system can realize the observation of different fields by carrying different sensors such as those based on marine engineering geology, chemistry, biology, and environment. Carrying resistivity and pore pressure sensors, the SRSS/ILMO powered by seawater batteries was used for a seabed engineering geology observation. The preliminary test results based on harbor environment show the effectiveness of the developed system.}, keywords = {buoy, real-time, remote monitoring, satellite communication, seabed observation, sensing, underwater acoustic communication}, doi = {10.3390/s19051255}, url = {https://app.dimensions.ai/details/publication/pub.1112750908 https://www.mdpi.com/1424-8220/19/5/1255/pdf}, author = {Liu, Lanjun and Liao, Zhibo and Chen, Caiyi and Chen, Jialin and Niu, Jiong and Jia, Yonggang and Guo, Xiujun and Chen, Zhaowei and Deng, Li and Xu, Haibo and Liu, Tao} } @article {RN123, title = {A Sensor Web Prototype for Cabled Seafloor Observatories in the East China Sea}, journal = {Journal of Marine Science and Engineering}, volume = {7}, number = {11}, year = {2019}, pages = {414}, type = {Journal Article}, abstract = {Seafloor observatories enable continuous power supply and real-time bidirectional data transmission, which marks a new way for marine environment monitoring. As in situ observation produces massive data in a constant way, the research involved with data acquisition, data transmission, data analysis, and user-oriented data application is vital to the close-loop operations of seafloor observatories. In this paper, we design and implement a sensor web prototype (ESOSW) to resolve seafloor observatory information processing in a plug-and-play way. A sensor web architecture is first introduced, which is information-oriented and structured into four layers enabling bidirectional information flow of observation data and control commands. Based on the layered architecture, the GOE Control Method and the Hot Swapping Interpretation Method are proposed as the plug-and-play mechanism for sensor control and data processing of seafloor observatory networks. ESOSW was thus implemented with the remote-control system, the data management system, and the real-time monitoring system, supporting managed sensor control and on-demand measurement. ESOSW was tested for plug-and-play enablement through a series of trials and was put into service for the East China Sea Seafloor Observation System. The experiment shows that the sensor web prototype design and implementation are feasible and could be a general reference to related seafloor observatory networks.}, keywords = {control systems, data processing, plug-and-play, seafloor observatories, sensor web}, issn = {2077-1312}, doi = {10.3390/jmse7110414}, url = {https://www.mdpi.com/2077-1312/7/11/414}, author = {Yu, Yang and Xu, Huiping and Xu, Changwei} } @article {RN110, title = {SMART Cables for Observing the Global Ocean: Science and Implementation}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {424}, type = {Journal Article}, abstract = {The ocean is key to understanding societal threats including climate change, sea level rise, ocean warming, tsunamis, and earthquakes. Because the ocean is difficult and costly to monitor, we lack fundamental data needed to adequately model, understand, and address these threats. One solution is to integrate sensors into future undersea telecommunications cables. This is the mission of the SMART subsea cables initiative (Science Monitoring And Reliable Telecommunications). SMART sensors would {\textquotedblleft}piggyback{\textquotedblright} on the power and communications infrastructure of a million kilometers of undersea fiber optic cable and thousands of repeaters, creating the potential for seafloor-based global ocean observing at a modest incremental cost. Initial sensors would measure temperature, pressure, and seismic acceleration. The resulting data would address two critical scientific and societal issues: the long-term need for sustained climate-quality data from the under-sampled ocean (e.g., deep ocean temperature, sea level, and circulation), and the near-term need for improvements to global tsunami warning networks. A Joint Task Force (JTF) led by three UN agencies (ITU/WMO/UNESCO-IOC) is working to bring this initiative to fruition. This paper explores the ocean science and early warning improvements available from SMART cable data, and the societal, technological, and financial elements of realizing such a global network. Simulations show that deep ocean temperature and pressure measurements can improve estimates of ocean circulation and heat content, and cable-based pressure and seismic-acceleration sensors can improve tsunami warning times and earthquake parameters. The technology of integrating these sensors into fiber optic cables is discussed, addressing sea and land-based elements plus delivery of real-time open data products to end users. The science and business case for SMART cables is evaluated. SMART cables have been endorsed by major ocean science organizations, and JTF is working with cable suppliers and sponsors, multilateral development banks and end users to incorporate SMART capabilities into future cable projects. By investing now, we can build up a global ocean network of long-lived SMART cable sensors, creating a transformative addition to the Global Ocean Observing System. }, keywords = {ocean cabled observatories, ocean circulation, ocean observing, SMART subsea cables, submarine telecommunications cables, tsunami early warning, UN Joint Task Force}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00424}, url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00424}, author = {Howe, Bruce M. and Arbic, Brian K. and Aucan, J{\'e}rome and Barnes, Christopher R. and Bayliff, Nigel and Becker, Nathan and Butler, Rhett and Doyle, Laurie and Elipot, Shane and Johnson, Gregory C. and Landerer, Felix and Lentz, Stephen and Luther, Douglas S. and M{\"u}ller, Malte and Mariano, John and Panayotou, Kate and Rowe, Charlotte and Ota, Hiroshi and Song, Y. Tony and Thomas, Maik and Thomas, Preston N. and Thompson, Philip and Tilmann, Frederik and Weber, Tobias and Weinstein, Stuart} } @article {RN118, title = {Southern Ocean Biogeochemical Float Deployment Strategy, With Example From the Greenwich Meridian Line (GO-SHIP A12)}, journal = {Journal of Geophysical Research: Oceans}, volume = {124}, number = {1}, year = {2019}, pages = {403-431}, type = {Journal Article}, abstract = {Biogeochemical Argo floats, profiling to 2,000-m depth, are being deployed throughout the Southern Ocean by the Southern Ocean Carbon and Climate Observations and Modeling program (SOCCOM). The goal is 200 floats by 2020, to provide the first full set of annual cycles of carbon, oxygen, nitrate, and optical properties across multiple oceanographic regimes. Building from no prior coverage to a sparse array, deployments are based on prior knowledge of water mass properties, mean frontal locations, mean circulation and eddy variability, winds, air-sea heat/freshwater/carbon exchange, prior Argo trajectories, and float simulations in the Southern Ocean State Estimate and Hybrid Coordinate Ocean Model (HYCOM). Twelve floats deployed from the 2014{\textendash}2015 Polarstern cruise from South Africa to Antarctica are used as a test case to evaluate the deployment strategy adopted for SOCCOM{\textquoteright}s 20 deployment cruises and 126 floats to date. After several years, these floats continue to represent the deployment zones targeted in advance: (1) Weddell Gyre sea ice zone, observing the Antarctic Slope Front, and a decadally-rare polynya over Maud Rise; (2) Antarctic Circumpolar Current (ACC) including the topographically steered Southern Zone chimney where upwelling carbon/nutrient-rich deep waters produce surprisingly large carbon dioxide outgassing; (3) Subantarctic and Subtropical zones between the ACC and Africa; and (4) Cape Basin. Argo floats and eddy-resolving HYCOM simulations were the best predictors of individual SOCCOM float pathways, with uncertainty after 2 years of order 1,000 km in the sea ice zone and more than double that in and north of the ACC.}, issn = {2169-9275}, doi = {10.1029/2018JC014059}, url = {https://doi.org/10.1029/2018JC014059}, author = {Talley, L. D. and Rosso, I. and Kamenkovich, I. and Mazloff, M. R. and Wang, J. and Boss, E. and Gray, A. R. and Johnson, K. S. and Key, R. M. and Riser, S. C. and Williams, N. L. and Sarmiento, J. L.} } @article {RN65, title = {Stratigraphic analysis of a sediment pond within the New England Mud Patch: New constraints from high-resolution chirp acoustic reflection data}, journal = {Marine Geology}, volume = {412}, year = {2019}, pages = {81-94}, type = {Journal Article}, abstract = {The New England Mud Patch (NEMP) is an anomaly on the Atlantic coast of North America. This ~13,000 km2 area, located south of Cape Cod between the ~60 m and 160 m isobaths, is a region of active fine-grained deposition on a shelf that is predominantly non-depositional or erosional. Prior studies theorized that NEMP sediments are derived from fines winnowed from Georges Bank, transported westward by coastal currents, and then settled in more quiescent conditions. A chirp seismic reflection (2015) and coring (2016) survey of part of the NEMP was conducted in support of a planned acoustic experiment for the Office of Naval Research. The survey focused on a ~30 km (E-W) by ~8 km (N-S) region between the 70 m and 85 m isobaths, encompassing a sediment {\textquotedblleft}pond{\textquotedblright} >12 m thick. The dense (250 m) survey lines allow a pseudo-3D stratigraphic interpretation. The sediment pond occupies an embayment eroded into pre-LGM substrate sediments, perhaps by glacial outwash. Marine sands beneath the mud are organized into oblique sand ridge morphology. The sense of obliquity, morphologic asymmetry, and internal dipping reflectors indicate that the sand ridges formed under east-directed transport. However, as evidenced by westward-prograding depocenters and onlap, NEMP deposition occurred under west-directed transport, consistent with modern shelf conditions. The onset of fine-grained deposition was therefore contemporaneous with a significant shift in the hydrologic regime. Muds deposited immediately above the sand ridges include a significant sand component, whose modal grain size is identical to that of the sand ridges. This admixture may indicate that, during the early stages of mud deposition, the tops of the sand ridges remained unburied and exposed to reworking. Episodic, storm-driven transport of sand to the muddy deposits may account for some of the sand component of NEMP sediments.}, keywords = {Chirp, Mud patch, New England shelf, Sand ridges, Vibracore}, issn = {0025-3227}, doi = {10.1016/j.margeo.2019.03.010}, url = {http://www.sciencedirect.com/science/article/pii/S0025322718304018}, author = {Goff, John A. and Reed, Allen H. and Gawarkiewicz, Glen and Wilson, Preston S. and Knobles, David P.} } @article {RN150, title = {Stress Drops on the Blanco Oceanic Transform Fault from Interstation Phase CoherenceStress Drops on the Blanco Oceanic Transform Fault from Interstation Phase Coherence}, journal = {Bulletin of the Seismological Society of America}, volume = {109}, number = {3}, year = {2019}, pages = {929-943}, type = {Journal Article}, abstract = { Oceanic transform faults display a wide range of earthquake stress drops, large aseismic slip, and along-strike variation in seismic coupling. We use and further develop a phase coherence-based method to calculate and analyze stress drops of 61 M>=5.0 events between 2000 and 2016 on the Blanco fault, off the coast of Oregon. With this method, we estimate earthquake rupture extents by examining how apparent source time functions (ASTFs) vary between stations. The variation is caused by the generation of seismic waves at different locations along the rupture, which arrive at different times depending on station location. We isolate ASTFs at a range of stations by comparing seismograms of collocated earthquakes and then use the interstation ASTF coherence to infer rupture extent and stress drop. We examine how our analysis is influenced by various factors, including poor trace alignment, relative earthquake locations, focal mechanism variation, azimuthal distribution of stations, and depth phase arrivals. We find that as alignment accuracy decreases or distance between earthquakes increases, coherence is reduced, but coherence is unaffected by focal mechanism variation or depth phase arrivals for our dataset. We calibrate the coherence{\textendash}rupture extent relationship based on the azimuthal distribution of stations. We find the phase coherence method can be used to estimate stress drops for offshore earthquakes, but is limited to M>=5.0 earthquakes for the Blanco fault due to poor trace alignment accuracy. The median stress drop on the Blanco fault is 8 MPa (with 95\% confidence limits of 6{\textendash}12 MPa) for 61 earthquakes. Stress drops are a factor of 1.7 (95\% confidence limits 0.8{\textendash}3.5) lower on the more aseismic northwest segment of the Blanco fault. These lower stress drops could be linked to reduced healing time due to higher temperatures, which reduce the depth of the seismogenic zone and shorten the seismic cycle.}, doi = {10.1785/0120180319}, url = {https://app.dimensions.ai/details/publication/pub.1113957538 http://eprints.whiterose.ac.uk/145490/1/manuscriptrevised2.pdf}, author = {Williams, Joshua R. and Hawthorne, Jessica C. and Rost, Sebastian and Wright, Tim J.} } @article {RN94, title = {Submarine: A subscription-based data streaming framework for integrating large facilities and advanced cyberinfrastructure}, journal = {Concurrency and Computation Practice and Experience}, year = {2019}, pages = {e5256}, type = {Journal Article}, abstract = {Large scientific facilities provide researchers with instrumentation, data, and data products that can accelerate scientific discovery. However, increasing data volumes coupled with limited local computational power prevents researchers from taking full advantage of what these facilities can offer. Many researchers looked into using commercial and academic cyberinfrastructure (CI) to process these data. Nevertheless, there remains a disconnect between large facilities and CI that requires researchers to be actively part of the data processing cycle. The increasing complexity of CI and data scale necessitates new data delivery models, those that can autonomously integrate large-scale scientific facilities and CI to deliver real-time data and insights. In this paper, we present our initial efforts using the Ocean Observatories Initiative project as a use case. In particular, we present a subscription-based data streaming service for data delivery that leverages the Apache Kafka data streaming platform. We also show how our solution can automatically integrate large-scale facilities with CI services for automated data processing.}, doi = {10.1002/cpe.5256}, url = {https://app.dimensions.ai/details/publication/pub.1113381084}, author = {Zamani, Ali Reza and AbdelBaky, Moustafa and Balouek-Thomert, Daniel and Villalobos, J. J. and Rodero, Ivan and Parashar, Manish} } @article {RN300, title = {Taking a close look at ocean circulation}, journal = {Science}, volume = {363}, number = {6426}, year = {2019}, pages = {456-457}, type = {Journal Article}, doi = {10.1126/science.aaw3111}, url = {https://app.dimensions.ai/details/publication/pub.1111828558}, author = {Rhein, Monika} } @article {RN144, title = {Towards a computing continuum: Enabling edge-to-cloud integration for data-driven workflows}, journal = {The International Journal of High Performance Computing Applications}, volume = {33}, number = {6}, year = {2019}, pages = {1159-1174}, type = {Journal Article}, abstract = {Dramatic changes in the technology landscape marked by increasing scales and pervasiveness of compute and data have resulted in the proliferation of edge applications aimed at effectively processing data in a timely manner. As the levels and fidelity of instrumentation increases and the types and volumes of available data grow, new classes of applications are being explored that seamlessly combine real-time data with complex models and data analytics to monitor and manage systems of interest. However, these applications require a fluid integration of resources at the edge, the core, and along the data path to support dynamic and data-driven application workflows, that is, they need to leverage a computing continuum. In this article, we present our vision for enabling such a computing continuum and specifically focus on enabling edge-to-cloud integration to support data-driven workflows. The research is driven by an online data-driven tsunami warning use case that is supported by the deployment of large-scale national environment observation systems. This article presents our overall approach as well as current status and next steps.}, keywords = {Continuum computing, data-driven workflows, edge-to-cloud integration, programming systems, streaming data-analytics}, doi = {10.1177/1094342019877383}, url = {https://app.dimensions.ai/details/publication/pub.1121117342}, author = {Balouek-Thomert, Daniel and Renart, Eduard Gibert and Zamani, Ali Reza and Simonet, Anthony and Parashar, Manish} } @article {RN99, title = {Transport Variability of the Irminger Sea Deep Western Boundary Current From a Mooring Array}, journal = {Journal of Geophysical Research-Oceans}, volume = {124}, number = {5}, year = {2019}, pages = {3246-3278}, type = {Journal Article}, abstract = {The Deep Western Boundary Current in the subpolar North Atlantic is the lower limb of the Atlantic Meridional Overturning Circulation and a key component of the global climate system. Here, a mooring array deployed at 60{\textdegree}N in the Irminger Sea, between 2014 and 2016, provides the longest continuous record of total Deep Western Boundary Current volume transport at this latitude. The 1.8-year averaged transport of water denser than σθ = 27.8 kg/m3 was -10.8 {\textpm} 4.9 Sv (mean {\textpm} 1 std; 1 Sv = 106 m3/s). Of this total, we find -4.1 {\textpm} 1.4 Sv within the densest layer (σθ > 27.88 kg/m3) that originated from the Denmark Strait Overflow. The lighter North East Atlantic Deep Water layer (σθ = 27.8{\textendash}27.88 kg/m3) carries -6.5 {\textpm} 7.7 Sv. The variability in transport ranges between 2 and 65 days. There is a distinct shift from high to low frequency with distance from the East Greenland slope. High-frequency fluctuations (2{\textendash}8 days) close to the continental slope are likely associated with topographic Rossby waves and/or cyclonic eddies. Here, perturbations in layer thickness make a significant (20{\textendash}60\%) contribution to transport variability. In deeper water, toward the center of the Irminger Basin, transport variance at 55 days dominates. Our results suggest that there has been a 1.8 Sv increase in total transport since 2005{\textendash}2006, but this difference can be accounted for by a range of methodological and data limitation biases}, issn = {2169-9275}, doi = {10.1029/2018JC014730}, author = {Hopkins, J. E. and Holliday, N. P. and Rayner, D. and Houpert, L. and Le Bras, I. and Straneo, F. and Wilson, C. and Bacon, S.} } @article {RN74, title = {Tsunami Wavefield Reconstruction and Forecasting Using the Ensemble Kalman Filter}, journal = {Geophysical Research Letters}, volume = {46}, number = {2}, year = {2019}, pages = {853-860}, type = {Journal Article}, abstract = {Offshore sensor networks like DONET and S-NET, providing real-time estimates of wave height through measurements of pressure changes along the seafloor, are revolutionizing local tsunami early warning. Data assimilation techniques, in particular, optimal interpolation (OI), provide real-time wavefield reconstructions and forecasts. Here we explore an alternative assimilation method, the ensemble Kalman filter (EnKF), and compare it to OI. The methods are tested on a scenario tsunami in the Cascadia subduction zone, obtained from a 2-D coupled dynamic earthquake and tsunami simulation. Data assimilation uses a 1-D linear long-wave model. We find that EnKF achieves more accurate and stable forecasts than OI, both at the coast and across the entire domain, especially for large station spacing. Although EnKF is more computationally expensive than OI, with development in high-performance computing, it is a promising candidate for real-time local tsunami early warning.}, issn = {0094-8276}, doi = {10.1029/2018GL080644}, url = {https://doi.org/10.1029/2018GL080644}, author = {Yang, Yuyun and Dunham, Eric M. and Barnier, Guillaume and Almquist, Martin} } @article {RN130, title = {Use of Profiler Moorings in the Ocean Observatories Initiative}, journal = {Oceanography \& Fisheries Open access Journal}, volume = {10}, number = {3}, year = {2019}, type = {Journal Article}, abstract = {This Mini Review is intended to describe the history, design, and summarize the performance of one class of mooring used by the Ocean Observatories Initiative. }, keywords = {buoy, Mooring, observatory, Ocean Observatories Initiative}, doi = {10.19080/ofoaj.2019.10.555788}, url = {https://app.dimensions.ai/details/publication/pub.1121754603 http://juniperpublishers.com/ofoaj/pdf/OFOAJ.MS.ID.555788.pdf}, author = {Palanza, Matthew} } @article {RN97, title = {Volcanic Tremor of Mt. Etna (Italy) Recorded by NEMO-SN1 Seafloor Observatory: A New Perspective on Volcanic Eruptions Monitoring}, journal = {Geosciences}, volume = {9}, number = {3}, year = {2019}, pages = {115}, type = {Journal Article}, abstract = {The NEMO-SN1 seafloor observatory, located 2100 m below sea level and about 40 km from Mt. Etna volcano, normally records a background seismic signal called oceanographic noise. This signal is characterized by high amplitude increases, lasting up to a few days, and by two typical 0.1 and 0.3 Hz frequencies in its spectrum. Particle motion analysis shows a strong E-W directivity, coinciding with the direction of sea waves; gravity waves induced by local winds are considered the main source of oceanographic noise. During the deployment of NEMO-SN1, the vigorous 2002{\textendash}2003 Mt. Etna eruption occurred. High-amplitude background signals were recorded during the explosive episodes accompanying the eruption. The spectral content of this signal ranges from 0.1 to 4 Hz, with the most powerful signal in the 0.5{\textendash}2 Hz band, typical of an Etna volcanic tremor. The tremor recorded by NEMO-SN1 shows a strong NW-SE directivity towards the volcano. Since the receiver is underwater, we inferred the presence of a circulation of magmatic fluids extended under the seafloor. This process is able to generate a signal strong enough to be recorded by the NEMO-SN1 seafloor observatory that hides frequencies linked to the oceanographic noise, permitting the offshore monitoring of the volcanic activity of Mt. Etna.}, keywords = {Mt. Etna volcano, oceanographic noise, volcanic monitoring by seafloor observatories, volcanic tremor}, doi = {10.3390/geosciences9030115}, url = {https://app.dimensions.ai/details/publication/pub.1112570519 https://www.mdpi.com/2076-3263/9/3/115/pdf}, author = {Sgroi, Tiziana and Di Grazia, Giuseppe and Favali, Paolo} } @article {RN107, title = {Waves and Swells in High Wind and Extreme Fetches, Measurements in the Southern Ocean}, journal = {Frontiers in Marine Science}, volume = {6}, year = {2019}, pages = {361}, type = {Journal Article}, abstract = {The generation and evolution of ocean waves by wind is one of the most complex phenomena in geophysics, and is of great practical significance. Predictive capabilities of respective wave models, however, are impaired by lack of field in situ observations, particularly in extreme Metocean conditions. The paper outlines and highlights important gaps in understanding the Metocean processes and suggests a major observational program in the Southern Ocean. This large, but poorly investigated part of the World Ocean is home to extreme weather around the year. The observational network would include distributed system of buoys (drifting and stationary) and autonomous surface vehicles (ASV), intended for measurements of waves and air-sea fluxes in the Southern Ocean. It would help to resolve the issues of limiting fetches, extreme Extra-Tropical cyclones, swell propagation and attenuation, wave-current interactions, and address the topics of wave-induced dispersal of floating objects, wave-ice interactions in the Marginal Ice Zone, Metocean climatology and its connection with the global climate.}, keywords = {air-sea and air-sea-land interaction processes, extra-tropical anticyclones, extreme wave, wave fetch, wind wave and swell}, issn = {2296-7745}, doi = {10.3389/fmars.2019.00361}, author = {Babanin, Alexander V. and Rogers, W. Erick and de Camargo, Ricardo and Doble, Martin and Durrant, Tom and Filchuk, Kirill and Ewans, Kevin and Hemer, Mark and Janssen, Tim and Kelly-Gerreyn, Boris and MacHutchon, Keith and McComb, Peter and Qiao, Fangli and Schulz, Eric and Skvortsov, Alex and Thomson, Jim and Vichi, Marcello and Violante-Carvalho, Nelson and Wang, David and Waseda, Takuji and Williams, Greg and Young, Ian R.} } @article {RN75, title = {Why Gliders Appreciate Good Company: Glider Assimilation in the Oregon-Washington Coastal Ocean 4DVAR System With and Without Surface Observations}, journal = {Journal of Geophysical Research: Oceans}, volume = {124}, number = {1}, year = {2019}, pages = {750-772}, type = {Journal Article}, abstract = {Gliders are low-power autonomous underwater vehicles used to obtain oceanic measurements in vertical sections. Assimilation of glider temperature and salinity into coastal ocean circulation models holds the potential to improve the ocean subsurface structure estimate. In this study, the impact of assimilation of glider observations is studied using a four-dimensional variational (4DVAR) data assimilation and forecast system set offshore of Oregon and Washington on the U.S. West Coast. Four test cases are compared: (1) no assimilation, (2) assimilation of glider temperature and salinity data alone, (3) assimilation of the glider data in combination with the surface observations including satellite sea surface temperature, sea surface height, and high-frequency radar surface velocities, and (4) assimilation of the surface data alone. It is found that the assimilation of glider observations alone creates unphysical eddies in the vicinity of the glider transect. As a consequence, the forecast errors in the surface velocity and temperature increase compared to the case without data assimilation. Assimilation of surface and subsurface observations in combination prevents these features from forming and reduces the errors in the forecasts for the subsurface fields compared to the other three experiments. These improvements persisted in 21-day forecasts run after the last data assimilation cycle. }, issn = {2169-9275}, doi = {10.1029/2018JC014230}, url = {https://doi.org/10.1029/2018JC014230}, author = {Pasmans, I. and Kurapov, A. L. and Barth, J. A. and Ignatov, A. and Kosro, P. M. and Shearman, R. K.} } @article {RN85, title = {Assessing Coastal SMAP Surface Salinity Accuracy and Its Application to Monitoring Gulf of Maine Circulation Dynamics}, journal = {Remote Sensing}, volume = {10}, number = {8}, year = {2018}, type = {Journal Article}, abstract = {Monitoring the cold and productive waters of the Gulf of Maine and their interactions with the nearby northwestern (NW) Atlantic shelf is important but challenging. Although remotely sensed sea surface temperature (SST), ocean color, and sea level have become routine, much of the water exchange physics is reflected in salinity fields. The recent invention of satellite salinity sensors, including the Soil Moisture Active Passive (SMAP) radiometer, opens new prospects in regional shelf studies. However, local sea surface salinity (SSS) retrieval is challenging due to both cold SST limiting salinity sensor sensitivity and proximity to land. For the NW Atlantic, our analysis shows that SMAP SSS is subject to an SST-dependent bias that is negative and amplifies in winter and early spring due to the SST-related drop in SMAP sensor sensitivity. On top of that, SMAP SSS is subject to a land contamination bias. The latter bias becomes noticeable and negative when the antenna land contamination factor (LC) exceeds 0.2\%, and attains maximum negative values at LC = 0.4\%. Coastward of LC = 0.5\%, a significant positive land contamination bias in absolute SMAP SSS is evident. SST and land contamination bias components are seasonally dependent due to seasonal changes in SST/winds and terrestrial microwave properties. Fortunately, it is shown that SSS anomalies computed relative to a satellite SSS climatology can effectively remove such seasonal biases along with the real seasonal cycle. SMAP monthly SSS anomalies have sufficient accuracy and applicability to extend nearer to the coasts. They are used to examine the Gulf of Maine water inflow, which displayed important water intrusions in between Georges Banks and Nova Scotia in the winters of 2016/17 and 2017/18. Water intrusion patterns observed by SMAP are generally consistent with independent measurements from the European Soil Moisture Ocean Salinity (SMOS) mission. Circulation dynamics related to the 2016/2017 period and enhanced wind-driven Scotian Shelf transport into the Gulf of Maine are discussed. }, keywords = {bias characteristics, Gulf of Maine, satellite salinity, Scotian Shelf}, issn = {2072-4292}, doi = {10.3390/rs10081232}, author = {Grodsky, A. Semyon and Vandemark, Douglas and Feng, Hui} } @article {RN15, title = {Atmospheric and Offshore Forcing of Temperature Variability at the Shelf Break Observations from the OOI Pioneer Array}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {72-79}, type = {Journal Article}, abstract = {Knowledge of heat balance and associated temperature variability in the Northwest Atlantic coastal ocean is important for understanding impacts of climate change such as how ocean warming will affect the management of fisheries. Heat balances are particularly complicated near the edge of the continental shelf, where the cross-shelf temperature gradients within the shelf-break front complicate the competing influences of air-sea flux anomalies versus ocean advection. We review the atmospheric and oceanic processes associated with heat balance over the Northwest Atlantic continental shelf and slope, with an emphasis on the scale-dependent nature of the heat balance. We then use data from the Ocean Observatories Initiative (OOI) Pioneer Array to demonstrate heat balance scale dependence at the southern New England shelf break, and the capability of the array to capture multiscale ocean processes. Comparison of the cumulative effects of air-sea heat fluxes measured at the OOI Pioneer Array from May 2015 to April 2016 with the actual temperature change shows the importance of advective processes in overall heat balance near the shelf break.}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.112}, url = {://WOS:000427367300012}, author = {Chen, K. and Gawarkiewicz, G. and Plueddemann, A.} } @article {RN89, title = {Augmenting Onshore GNSS Displacements With Offshore Observations to Improve Slip Characterization for Cascadia Subduction Zone Earthquakes}, journal = {Geophysical Research Letters}, volume = {45}, number = {12}, year = {2018}, pages = {6008-6017}, type = {Journal Article}, abstract = {For the Cascadia subduction zone, Mw~8 megathrust earthquake hazard is of particular interest because uncertainties in the predicted tsunami size affect evacuation alerts. To reduce these uncertainties, we examine how augmenting the current Global Navigation Satellite Systems (GNSS) network in Cascadia with offshore stations improves static slip inversions for Mw~8 megathrust earthquakes at different rupture depths. We test two offshore coseismic data types: vertical-only bottom pressure sensors and pressure sensors combined with GNSS-Acoustic aided horizontal positions. We find that amphibious networks best constrain slip for a shallow earthquake compared to onshore-only networks when offshore stations are located above the rupture. However, inversions using vertical-only offshore data underestimate shallow slip and tsunami impact. Including offshore horizontal observations improves slip estimates, particularly maximum slip. This suggests that while real-time GNSS-Acoustic sensors may have a long development timeline, they will have more impact for static inversion-based tsunami early warning systems than bottom pressure sensors.}, issn = {0094-8276}, doi = {10.1029/2018GL078233}, url = {https://doi.org/10.1029/2018GL078233}, author = {Saunders, Jessie K. and Haase, Jennifer S.} } @article {RN90, title = {Automated Large-Scale Full Seismic Waveform Inversion for North America and the North Atlantic}, journal = {Journal of Geophysical Research: Solid Earth}, volume = {123}, number = {7}, year = {2018}, pages = {5902-5928}, type = {Journal Article}, abstract = {We present a new anisotropic seismic tomography model based on a multiscale full seismic waveform inversion for crustal and upper-mantle structure from the western edge of North America across the North Atlantic and into Europe. The gradient-based inversion strategy utilizes the adjoint state method coupled with an L-BFGS quasi-Newton optimization scheme. To improve the handling of large data quantities in the context of full seismic waveform inversions, we developed a workflow framework automating the procedure across all stages, enabling us to confidently invert for waveforms from 72 events recorded at 7,737 unique stations, resulting in a total of 144,693 raypaths, most of them with three-component recordings. The final model after 20 iterations is able to explain complete waveforms including body as well as surface waves of earthquakes that were not used in the inversion down to periods of around 30 s. The model is complemented by a detailed resolution analysis in the form of 3-D distributions of direction-dependent resolution lengths.}, issn = {2169-9313}, doi = {10.1029/2017JB015289}, url = {https://doi.org/10.1029/2017JB015289}, author = {Krischer, Lion and Fichtner, Andreas and Boehm, Christian and Igel, Heiner} } @article {RN93, title = {Autonomous Data Collection Using a Self-Organizing Map}, volume = {29}, number = {5}, year = {2018}, pages = {1703-1715}, type = {Journal Article}, abstract = {The self-organizing map (SOM) is an unsupervised learning technique providing a transformation of a high-dimensional input space into a lower dimensional output space. In this paper, we utilize the SOM for the traveling salesman problem (TSP) to develop a solution to autonomous data collection. Autonomous data collection requires gathering data from predeployed sensors by moving within a limited communication radius. We propose a new growing SOM that adapts the number of neurons during learning, which also allows our approach to apply in cases where some sensors can be ignored due to a lower priority. Based on a comparison with available combinatorial heuristic algorithms for relevant variants of the TSP, the proposed approach demonstrates improved results, while also being less computationally demanding. Moreover, the proposed learning procedure can be extended to cases where particular sensors have varying communication radii, and it can also be extended to multivehicle planning.}, keywords = {Data collection, Neurons, Planning, Robot sensing systems, Urban areas}, doi = {10.1109/tnnls.2017.2678482}, url = {https://app.dimensions.ai/details/publication/pub.1084207070}, author = {Faigl, Jan and Hollinger, Geoffrey A.} } @article {RN14, title = {The Changing Nature of Shelf-Break Exchange Revealed by the OOI Pioneer Array}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {60-70}, type = {Journal Article}, abstract = {Although the continental shelf and slope south of New England have been the subject of recent studies that address decadal-scale warming and interannual variability of water mass properties, it is not well understood how these changes affect shelf-break exchange processes. In recent years, observations of anomalous shelf and slope conditions obtained from the Ocean Observatories Initiative Pioneer Array and other regional observing programs suggest that onshore intrusions of warm, salty waters are becoming more prevalent. Mean cross-shelf transects constructed from Pioneer Array glider observations collected from April 2014 through December 2016 indicate that slope waters have been warmer and saltier. We examine shelf-break exchange events and anomalous onshore intrusions of warm, salty water associated with warm core rings located near the shelf break in spring 2014 and winter 2017 using observations from the Pioneer Array and other sources. We also describe an additional cross-shelf intrusion of ring water in September 2014 to demonstrate that the occurrence of high-salinity waters extending across the continental shelf is rare. Observations from the Pioneer Array and other sources show warm core ring and Gulf Stream water masses intrude onto the continental shelf more frequently and penetrate further onshore than in previous decades. }, issn = {1042-8275}, doi = {10.5670/oceanog.2018.110}, url = {://WOS:000427367300010}, author = {Gawarkiewicz, G. and Todd, R. E. and Zhang, W. F. and Partida, J. and Gangopadhyay, A. and Monim, M. U. H. and Fratantoni, P. and Mercer, A. M. and Dent, M.} } @article {RN22, title = {Deep Convection in the Irminger Sea Observed with a Dense Mooring Array}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {50-59}, type = {Journal Article}, abstract = {Deep convection is a key process in the Atlantic Meridional Overturning Circulation, but because it acts at small scales, it remains poorly resolved by climate models. The occurrence of deep convection depends on weak initial stratification and strong surface buoyancy forcing, conditions that are satisfied in only a few ocean basins. In 2014, one of the Ocean Observatories Initiative (OOI) global arrays was installed close to the Central Irminger Sea (CIS) and the Long-term Ocean Circulation Observations (LOCO) moorings in the central Irminger Sea. These programs{\textquoteright} six moorings are located in the center of an area of deep convection and are distributed within a 50 km radius, thus offering detailed insight into spatial differences during the strong convection events that occurred during the winters of 2014/2015 and 2015/2016. Deep mixed layers, down to approximately 1,600 m, formed during both winters. The properties of the convectively renewed water mass at each mooring converge to a common temperature and salinity before restratification sets in at the end of winter. The largest differences in onset (or timing) of convection and restratification are seen between the northernmost and southernmost moorings. High-resolution atmospheric reanalysis data show there is higher atmospheric forcing at the northernmost mooring due to a more favorable position with respect to the Greenland tip jet. Nevertheless, earlier onset, and more continuous cooling and deepening of mixed layers, occurs at the southernmost mooring, while convection at the northern mooring is frequently interrupted by warm events. We propose that these warm events are associated with eddies and filaments originating from the Irminger Current off the coast of Greenland and that convection further south benefits from cold inflow from the southwest. }, issn = {10428275}, doi = {10.5670/oceanog.2018.109}, author = {de Jong, M. Femke and Oltmanns, Marilena and Karstensen, Johannes and de Steur, Laura} } @article {RN3, title = {Deep-Sea Volcanic Eruptions Create Unique Chemical and Biological Linkages Between the Subsurface Lithosphere and the Oceanic Hydrosphere}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {128-135}, type = {Journal Article}, abstract = {In April 2015, pressure recorders, seismometers, and hydrophones attached to the Ocean Observatories Initiative (OOI) Cabled Array on Axial Seamount detected, in real time, a volcanic eruption predominantly located along the north rift zone (NRZ). Real-time detection enabled a rapid response cruise to augment OOI data with ship-based physical, chemical, and biological sampling of the eruption and the new lava flows. The combined data set demonstrates the synergistic value of real-time monitoring combined with rapid response efforts that sample beyond the boundaries of a fixed cabled array. These combined data show that the 2015 eruption gave rise to chemically and microbiologically variable hydrothermal plumes over new NRZ lava flows, reflecting chemical and biological linkages between the subsurface lithosphere and the oceanic hydrosphere. The warmest and least diluted plume near the new lava flows was 0.119{\textdegree}C above background seawater and hosted thermophilic and hyperthermophilic taxa that are typically identified in hydrothermal fluids emanating from the warm subsurface. Cooler and more diluted hydrothermal plumes farther from a hydrothermal fluid source were 0.072{\textdegree}{\textendash}0.078{\textdegree}C above background seawater and hosted mesophilic and psychrophilic taxa that are typically identified in neutrally buoyant plumes at persistent hydrothermal venting sites. Potentially chemosynthetic microbial lineages, including Epsilonproteobacteria, Gammaproteobacteria, and Methanococcales, were positively correlated with elevated temperature anomalies. These data suggest that hydrothermal fluid flow through new lava flows on the NRZ supported diverse microbial communities for several months following the 2015 eruption and that subsurface heterogeneity contributed to the structure of unique hydrothermal-plume-hosted microbial communities.}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.120}, url = {://WOS:000427367300020}, author = {Spietz, R. L. and Butterfield, D. A. and Buck, N. J. and Larson, B. I. and Chadwick, W. W. and Walker, S. L. and Kelley, D. S. and Morris, R. M.} } @article {RN32, title = {Detection of climate change-driven trends in phytoplankton phenology}, journal = {Glob Chang Biol}, volume = {24}, number = {1}, year = {2018}, pages = {e101-e111}, type = {Journal Article}, abstract = {The timing of the annual phytoplankton spring bloom is likely to be altered in response to climate change. Quantifying that response has, however, been limited by the typically coarse temporal resolution (monthly) of global climate models. Here, we use higher resolution model output (maximum 5 days) to investigate how phytoplankton bloom timing changes in response to projected 21st century climate change, and how the temporal resolution of data influences the detection of long-term trends. We find that bloom timing generally shifts later at mid-latitudes and earlier at high and low latitudes by ~5 days per decade to 2100. The spatial patterns of bloom timing are similar in both low (monthly) and high (5 day) resolution data, although initiation dates are later at low resolution. The magnitude of the trends in bloom timing from 2006 to 2100 is very similar at high and low resolution, with the result that the number of years of data needed to detect a trend in phytoplankton phenology is relatively insensitive to data temporal resolution. We also investigate the influence of spatial scales on bloom timing and find that trends are generally more rapidly detectable after spatial averaging of data. Our results suggest that, if pinpointing the start date of the spring bloom is the priority, the highest possible temporal resolution data should be used. However, if the priority is detecting long-term trends in bloom timing, data at a temporal resolution of 20 days are likely to be sufficient. Furthermore, our results suggest that data sources which allow for spatial averaging will promote more rapid trend detection.}, issn = {1365-2486 (Electronic) 1354-1013 (Linking)}, doi = {10.1111/gcb.13886}, url = {https://www.ncbi.nlm.nih.gov/pubmed/28871605}, author = {Henson, S. A. and Cole, H. S. and Hopkins, J. and Martin, A. P. and Yool, A.} } @article {RN79, title = {Distributed natural gas venting offshore along the Cascadia margin}, journal = {Nature Communications}, volume = {9}, number = {1}, year = {2018}, pages = {3264}, type = {Journal Article}, abstract = {Widespread gas venting along the Cascadia margin is investigated from acoustic water column data and reveals a nonuniform regional distribution of over 1100 mapped acoustic flares. The highest number of flares occurs on the shelf, and the highest flare density is seen around the nutrition-rich outflow of the Juan de Fuca Strait. We determine \~{}430 flow-rates at \~{}340 individual flare locations along the margin with instantaneous in situ values ranging from \~{}6 mL min-1 to \~{}18 L min-1. Applying a tidal-modulation model, a depth-dependent methane density, and extrapolating these results across the margin using two normalization techniques yields a combined average in situ flow-rate of \~{}88 {\texttimes} 106 kg y-1. The average methane flux-rate for the Cascadia margin is thus estimated to \~{}0.9 g y-1m-2. Combined uncertainties result in a range of these values between 4.5 and 1800\% of the estimated mean values.}, issn = {2041-1723}, doi = {10.1038/s41467-018-05736-x}, url = {https://doi.org/10.1038/s41467-018-05736-x}, author = {Riedel, M. and Scherwath, M. and Romer, M. and Veloso, M. and Heesemann, M. and Spence, G. D.} } @article {RN48, title = {Education and Public Engagement in OOI Lessons Learned from the Field}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {138-146}, type = {Journal Article}, abstract = {The Ocean Observing Initiative (OOI) was designed to advance understanding of complex oceanographic processes by acquiring large quantities of data at six key locations in the world ocean. The OOI Education and Public Engagement (EPE) Implementing Organization has built an educational cyberinfrastructure and developed interactive tools targeted for undergraduate-level learners that enable easy access to OOI data, images, and video. To develop the suite of OOI education tools, EPE used an iterative design process, including needs assessment, tool prototyping, and usability testing in undergraduate classrooms. Data visualization and concept mapping tools were envisioned as a way to help undergraduates link concepts students see in oceanography textbooks to real-world phenomena. A Data Investigation Builder (DIB) was constructed to assist professors in designing data activities. During the usability testing, professors provided valuable feedback that allowed EPE to improve the tools. Based on the lessons learned from EPE, in 2016 we developed a new prototype set of Data Explorations that were more modular and easier to integrate into an undergraduate lecture or problem set. This paper reviews how the EPE toolset was developed, including establishment of requirements for the tools and incorporation of lessons learned from the user needs assessment and the results of usability testing of prototype tools.}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.122}, url = {://WOS:000427367300022}, author = {McDonnell, J. and deCharon, A. and Lichtenwalner, C. S. and Hunter-Thomson, K. and Halversen, C. and Schofield, O. and Glenn, S. and Ferraro, C. and Lauter, C. and Hewlett, J.} } @article {RN40, title = {Episodic Southern Ocean Heat Loss and Its Mixed Layer Impacts Revealed by the Farthest South Multiyear Surface Flux Mooring}, journal = {Geophysical Research Letters}, volume = {45}, number = {10}, year = {2018}, pages = {5002-5010}, type = {Journal Article}, abstract = {The Ocean Observatories Initiative air-sea flux mooring deployed at 54.08{\textdegree}S, 89.67{\textdegree}W, in the southeast Pacific sector of the Southern Ocean, is the farthest south long-term open ocean flux mooring ever deployed. Mooring observations (February 2015 to August 2017) provide the first in situ quantification of annual net air-sea heat exchange from one of the prime Subantarctic Mode Water formation regions. Episodic turbulent heat loss events (reaching a daily mean net flux of -294 W/m2) generally occur when northeastward winds bring relatively cold, dry air to the mooring location, leading to large air-sea temperature and humidity differences. Wintertime heat loss events promote deep mixed layer formation that lead to Subantarctic Mode Water formation. However, these processes have strong interannual variability; a higher frequency of 2 σ and 3 σ turbulent heat loss events in winter 2015 led to deep mixed layers (>300 m), which were nonexistent in winter 2016.}, issn = {0094-8276}, doi = {10.1029/2017gl076909}, url = {://WOS:000435262000052}, author = {Ogle, S. E. and Tamsitt, V. and Josey, S. A. and Gille, S. T. and Cerovecki, I. and Talley, L. D. and Weller, R. A.} } @article {RN64, title = {Frontal Subduction of the Mid-Atlantic Bight Shelf Water at the Onshore Edge of a Warm-Core Ring}, journal = {Journal of Geophysical Research: Oceans}, volume = {123}, number = {11}, year = {2018}, pages = {7795-7818}, type = {Journal Article}, abstract = {This work studies the subduction of the shelf water along the onshore edge of a warm-core ring that impinges on the edge of the Mid-Atlantic Bight continental shelf. The dynamical analysis is based on observations by satellites and from the Ocean Observatories Initiative Pioneer Array observatory as well as idealized numerical model simulations. They together show that frontogenesis-induced submesoscale frontal subduction with order-one Rossby and Froude numbers occurs on the onshore edge of the ring. The subduction flow results from the onshore migration of the warm-core ring that intensifies the density front on the interface of the ring and shelf waters. The subduction is a part of the cross-front secondary circulation trying to relax the intensifying density front. The dramatically different physical and biogeochemical properties of the ring and shelf waters provide a great opportunity to visualize the subduction phenomenon. Entrained by the ring-edge current, the subducted shelf water is subsequently transported offshore below a surface layer of ring water and alongside of the surface-visible shelf-water streamer. It explains the historical observations of isolated subsurface packets of shelf water along the ring periphery in the slope sea. Model-based estimate suggests that this type of subduction-associated subsurface cross-shelfbreak transport of the shelf water could be substantial relative to other major forms of shelfbreak water exchange. This study also proposes that outward spreading of the ring-edge front by the frontal subduction may facilitate entrainment of the shelf water by the ring-edge current and enhances the shelf-water streamer transport at the shelf edge.}, issn = {2169-9275}, doi = {10.1029/2018JC013794}, url = {https://doi.org/10.1029/2018JC013794}, author = {Zhang, Weifeng G. and Partida, Jacob} } @article {RN86, title = {Geostatistical Analysis of Mesoscale Spatial Variability and Error in SeaWiFS and MODIS/Aqua Global Ocean Color Data}, journal = {Journal of Geophysical Research: Oceans}, volume = {123}, number = {1}, year = {2018}, pages = {22-39}, type = {Journal Article}, abstract = {Mesoscale (10{\textendash}300 km, weeks to months) physical variability strongly modulates the structure and dynamics of planktonic marine ecosystems via both turbulent advection and environmental impacts upon biological rates. Using structure function analysis (geostatistics), we quantify the mesoscale biological signals within global 13 year SeaWiFS (1998{\textendash}2010) and 8 year MODIS/Aqua (2003{\textendash}2010) chlorophyll a ocean color data (Level-3, 9 km resolution). We present geographical distributions, seasonality, and interannual variability of key geostatistical parameters: unresolved variability or noise, resolved variability, and spatial range. Resolved variability is nearly identical for both instruments, indicating that geostatistical techniques isolate a robust measure of biophysical mesoscale variability largely independent of measurement platform. In contrast, unresolved variability in MODIS/Aqua is substantially lower than in SeaWiFS, especially in oligotrophic waters where previous analysis identified a problem for the SeaWiFS instrument likely due to sensor noise characteristics. Both records exhibit a statistically significant relationship between resolved mesoscale variability and the low-pass filtered chlorophyll field horizontal gradient magnitude, consistent with physical stirring acting on large-scale gradient as an important factor supporting observed mesoscale variability. Comparable horizontal length scales for variability are found from tracer-based scaling arguments and geostatistical decorrelation. Regional variations between these length scales may reflect scale dependence of biological mechanisms that also create variability directly at the mesoscale, for example, enhanced net phytoplankton growth in coastal and frontal upwelling and convective mixing regions. Global estimates of mesoscale biophysical variability provide an improved basis for evaluating higher resolution, coupled ecosystem-ocean general circulation models, and data assimilation.}, issn = {2169-9275}, doi = {10.1002/2017JC013023}, url = {https://doi.org/10.1002/2017JC013023}, author = {Glover, David M. and Doney, Scott C. and Oestreich, William K. and Tullo, Alisdair W.} } @article {RN39, title = {The impact of wave energy converter arrays on wave-induced forcing in the surf zone}, journal = {Ocean Engineering}, volume = {161}, year = {2018}, pages = {322-336}, type = {Journal Article}, abstract = {An alternative metric for assessing nearshore hydrodynamic impact due to Wave Energy Converter (WEC) arrays is presented that is based on the modeled changes in alongshore radiation stress gradients in the lee of the array. The metric is developed using a previously observed relationship between measured radiation stresses and alongshore current magnitudes. Next, a parametric study is conducted using the spectral model SWAN to analyze the nearshore impact of different WEC array designs. A realistic range of array configurations, locations, and incident wave conditions are examined and conditions that generate alongshore radiation stress gradients exceeding a chosen impact threshold on a uniform beach are identified. Finally, the methodology is applied to two permitted WEC test sites to assess the applicability of the results to sites with more realistic bathymetries. For these sites, the overall trends seen in the changes in wave height, direction, and radiation stress gradients in the lee of the array are similar to those seen in the parametric study. However, interactions between the wave field and real bathymetry induce additional alongshore variability in wave-induced forcing. Results indicate that array-induced changes can exceed the natural variability up to 15\% of the time with certain array designs and locations. }, keywords = {Nearshore impact, Radiation stress, SWAN, Wave energy, Wave farm}, issn = {0029-8018}, doi = {10.1016/j.oceaneng.2018.03.077}, url = {://WOS:000437819800026}, author = {O{\textquoteright}Dea, A. and Haller, M. C. and Ozkan-Haller, H. T.} } @article {RN41, title = {Increased risk of a shutdown of ocean convection posed by warm North Atlantic summers}, journal = {Nature Climate Change}, volume = {8}, number = {4}, year = {2018}, pages = {300-+}, type = {Journal Article}, abstract = {A shutdown of ocean convection in the subpolar North Atlantic, triggered by enhanced melting over Greenland, is regarded as a potential transition point into a fundamentally different climate regime1,2,3. Noting that a key uncertainty for future convection resides in the relative importance of melting in summer and atmospheric forcing in winter, we investigate the extent to which summer conditions constrain convection with a comprehensive dataset, including hydrographic records that are over a decade in length from the convection regions. We find that warm and fresh summers, characterized by increased sea surface temperatures, freshwater concentrations and melting, are accompanied by reduced heat and buoyancy losses in winter, which entail a longer persistence of the freshwater near the surface and contribute to delaying convection. By shortening the time span for the convective freshwater export, the identified seasonal dynamics introduce a potentially critical threshold that is crossed when substantial amounts of freshwater from one summer are carried over into the next and accumulate. Warm and fresh summers in the Irminger Sea are followed by particularly short convection periods. We estimate that in the winter 2010{\textendash}2011, after the warmest and freshest Irminger Sea summer on our record, ~40\% of the surface freshwater was retained. }, issn = {1758-678x}, doi = {10.1038/s41558-018-0105-1}, url = {://WOS:000429194600015}, author = {Oltmanns, M. and Karstensen, J. and Fischer, J.} } @article {RN82, title = {Loggerhead turtles are good ocean-observers in stratified mid-latitude regions}, journal = {Estuarine, Coastal and Shelf Science}, volume = {213}, year = {2018}, pages = {128-136}, type = {Journal Article}, abstract = {Since 2009, we have deployed 167 satellite tags on loggerheads within the U.S. Mid-Atlantic Bight of the Northwest Atlantic Ocean. These tags collect and transmit location, temperature and depth information and have yielded 18,790 temperature-depth profiles during the highly stratified season (01 June {\textendash}04 October) for the region. This includes 16,371 profiles exceeding the mixed-layer depth, and, of those, 11,591 full water column profiles reaching the ocean floor. The US MAB is a dynamic ecosystem that is difficult to model due to a combination of complex seasonal water masses and currents and a limited set of tools for taking in situ measurements. This region is also prime foraging habitat for loggerhead sea turtles during the late-spring to summer months. Here we suggest that the habitat usage of loggerhead turtles in the Mid-Atlantic Bight make them good ocean observers within this difficult to model, highly stratified region. The use of turtle-borne telemetry devices has the potential to improve resolution of in situ temperature through depth data and in turn improve oceanographic model outputs. It is imperative that model outputs are continuously updated, as they are regularly used to inform management and conservation decisions.}, keywords = {Cold pool, Depth, Northwest Atlantic Ocean, Satellite telemetry, Temperature}, issn = {0272-7714}, doi = {10.1016/j.ecss.2018.08.019}, url = {http://www.sciencedirect.com/science/article/pii/S0272771418303044}, author = {Patel, Samir H. and Barco, Susan G. and Crowe, Leah M. and Manning, James P. and Matzen, Eric and Smolowitz, Ronald J. and Haas, Heather L.} } @article {RN29, title = {Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic}, journal = {Ocean Science Discussions}, year = {2018}, pages = {1-27}, type = {Journal Article}, abstract = {A long-term mean flow field for the subpolar North Atlantic region with a horizontal resolution of approximately 25 km is created by gridding Argo-derived velocity vectors using two different topography-following interpolation schemes. The 10-day float displacements in the typical drift depths of 1000 to 1500 m represent the flow in the Labrador Sea Water density range. Both mapping algorithms separate the flow field into potential vorticity (PV) conserving, i.e., topography-following contribution and a deviating part, which we define as the eddy contribution. To verify the significance of the separation, we compare the mean flow and the eddy kinetic energy (EKE), derived from both mapping algorithms, with those obtained from multiyear mooring observations. The PV-conserving mean flow is characterized by stable boundary currents along all major topographic features including shelf breaks and basin-interior topographic ridges such as the Reykjanes Ridge or the Rockall Plateau. Mid-basin northward advection pathways from the northeastern Labrador Sea into the Irminger Sea and from the Mid-Atlantic Ridge region into the Iceland Basin are well-resolved. An eastward flow is present across the southern boundary of the subpolar gyre near 52o N, the latitude of the Charlie Gibbs Fracture Zone (CGFZ). The mid-depth EKE field resembles most of the satellite-derived surface EKE field. However, noticeable differences exist along the northward advection pathways in the Irminger Sea and the Iceland Basin, where the deep EKE exceeds the surface EKE field. Further, the ratio between mean flow and the square root of the EKE, the Peclet number, reveals distinct advection-dominated regions as well as basin-interior regimes in which mixing is prevailing. How to cite. Fischer, J., Karstensen, J., Oltmanns, M., and Schmidtko, S.: Mean circulation and EKE distribution in the Labrador Sea Water level of the subpolar North Atlantic, Ocean Sci., 14, 1167{\textendash}1183, https://doi.org/10.5194/os-14-1167-2018, 2018.}, issn = {1812-0822}, doi = {10.5194/os-2018-56}, url = {https://staging-ddpp.dimensions.ai/details/publication/pub.1103986302 https://www.ocean-sci-discuss.net/os-2018-56/os-2018-56.pdf}, author = {Fischer, J{\"u}rgen and Karstensen, Johannes and Oltmanns, Marilena and Schmidtko, Sunke} } @article {RN88, title = {Measuring Seafloor Strain With an Optical Fiber Interferometer}, journal = {Earth and Space Science}, volume = {5}, number = {8}, year = {2018}, pages = {371-379}, type = {Journal Article}, abstract = {We monitored the length of an optical fiber cable stretched between two seafloor anchors separated by 200 m at a depth of 1900 m, 90 km west of Newport, OR, near the toe of the accretionary prism of the Cascadia subduction zone. We continuously recorded length changes using an equal arm Michelson interferometer formed by the sensing cable fiber and a mandrel-wound reference fiber. A second, nearly identical fiber interferometer (sharing the same cable and housing), differing only in its fiber{\textquoteright}s temperature coefficient, was recorded simultaneously, allowing the separation of optical path length change due to temperature from that due to strain. Data were collected for 100 days following deployment on 18 October 2015, and showed an overall strain (length change) of -10.7 με (shorter by 2.14 mm). At seismic periods, the sensitivity was a few nε; at tidal periods the noise level was a few tens of nε. The RMS variation after removal of a -79 nε/day drift over the final 30 days was 36 nε. No strain transients were observed. An unexpected response to the varying hydrostatic load from ocean tides was observed with a coefficient of -101 nε per meter of ocean tide height.}, issn = {2333-5084}, doi = {10.1029/2018EA000418}, url = {https://doi.org/10.1029/2018EA000418}, author = {Zumberge, Mark A. and Hatfield, William and Wyatt, Frank K.} } @article {RN1, title = {Mechanics of fault reactivation before, during, and after the 2015 eruption of Axial Seamount}, journal = {Geology}, volume = {46}, number = {5}, year = {2018}, pages = {447-450}, type = {Journal Article}, abstract = {Ocean-bottom seismic and seafloor pressure data from the Ocean Observatories Initiative{\textquoteright}s Cabled Array were used to study fault reactivation within Axial Seamount (offshore Oregon, USA). Microearthquakes that occurred during 2015{\textendash}2016 were located on portions of an outward-dipping ring fault system that was reactivated in response to the inflation and deflation of the underlying magma chamber. Prior to an eruption in April 2015, focal mechanisms showed a pattern of normal slip consistent with the differential vertical uplift of the caldera floor relative to the rim. During the eruption, seismic activity remained localized along these outward-dipping structures; however, the slip direction was reversed as the caldera floor subsided. After the eruption, as the volcano reinflated and the caldera floor uplifted, these faults exhibited sparser seismicity with a more heterogeneous pattern of slip. Monitoring the evolution of ring fault behavior through time may have utility as a metric in future eruption forecasts.}, issn = {0091-7613}, doi = {10.1130/G39978.1}, url = {://WOS:000431359800019}, author = {Levy, S. and Bohnenstiehl, D. R. and Sprinkle, P. and Boettcher, M. S. and Wilcock, W. S. D. and Tolstoy, M. and Waldhauser, F.} } @article {RN302, title = {Meridional heat transport variability induced by mesoscale processes in the subpolar North Atlantic}, journal = {Nature Communications}, volume = {9}, number = {1}, year = {2018}, pages = {1124}, type = {Journal Article}, doi = {10.1038/s41467-018-03134-x}, url = {https://app.dimensions.ai/details/publication/pub.1101559905 https://www.nature.com/articles/s41467-018-03134-x.pdf}, author = {Zhao, Jian and Bower, Amy and Yang, Jiayan and Lin, Xiaopei and Holliday, N. Penny} } @article {RN80, title = {Newly detected earthquakes in the Cascadia subduction zone linked to seamount subduction and deformed upper plate}, journal = {Geology}, volume = {46}, number = {11}, year = {2018}, pages = {943-946}, type = {Journal Article}, abstract = {Data from an amphibious seismic network in Cascadia (northwest North America) provide unique near-source observations to assess the influence of subducting topography on seismicity. Using subspace detection, we detect and locate 222 events in two separate clusters, near a subducted seamount and a possibly accreted seamount. Seismicity in both clusters is largely shallower than the plate interface and exhibits occasional swarm-like behavior. This implies that the seamount is subducting aseismically via weak coupling with the overriding plate, while earthquakes in the upper plate arise from a high degree of fracturing due to seamount interaction, and the accreted seamount induced similar fracturing before off-scraping. }, issn = {0091-7613}, doi = {10.1130/G45354.1}, url = {https://doi.org/10.1130/G45354.1}, author = {Morton, Emily A. and Bilek, Susan L. and Rowe, Charlotte A.} } @article {RN21, title = {The North Atlantic Biological Pump INSIGHTS FROM THE OCEAN OBSERVATORIES INITIATIVE IRMINGER SEA ARRAY}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {42-49}, type = {Journal Article}, abstract = {The biological pump plays a key role in the global carbon cycle by transporting photosynthetically fixed organic carbon into the deep ocean, where it can be sequestered from the atmosphere over annual or longer time scales if exported below the winter ventilation depth. In the subpolar North Atlantic, carbon sequestration via the biological pump is influenced by two competing forces: a spring diatom bloom that features large, fast-sinking biogenic particles, and deep winter mixing that requires particles to sink much further than in other ocean regions to escape winter ventilation. We synthesize biogeochemical sensor data from the first two years of operations at the Ocean Observatories Initiative Irminger Sea Array of moorings and gliders (September 2014{\textendash}July 2016), providing the first simultaneous year-round observations of biological carbon cycling processes in both the surface ocean and the seasonal thermocline in this critical but previously undersampled region. These data show significant mixed layer net autotrophy during the spring bloom and significant respiration in the seasonal thermocline during the stratified season (~5.9 mol C m{\textendash}2 remineralized between 200 m and 1,000 m). This respired carbon is subsequently ventilated during winter convective mixing (>1,000 m), a significant reduction in potential carbon sequestration. This highlights the importance of year-round observations to accurately constrain the biological pump in the subpolar North Atlantic, as well as other high-latitude regions that experience deep winter mixing.}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.108}, url = {://WOS:000427367300008}, author = {Palevsky, H. I. and Nicholson, D. P.} } @article {RN10, title = {Observation and Modeling of Hydrothermal Response to the 2015 Eruption at Axial Seamount, Northeast Pacific}, journal = {Geochemistry, Geophysics, Geosystems}, number = {ja}, year = {2018}, type = {Journal Article}, abstract = {The 2015 eruption at Axial Seamount, an active volcano at a depth of 1500 m in the Northeast Pacific, marked the first time a seafloor eruption was detected and monitored by an in situ cabled observatory{\textemdash}the Cabled Array, which is part of the Ocean Observatories Initiative. After the onset of the eruption, eight cabled and noncabled instruments on the seafloor recorded unusual, nearly synchronous and spatially uniform temperature increases of 0.6{\textendash}0.7{\textdegree}C across the southern half of the caldera and neighboring areas. These temperature signals were substantially different from those observed after the 2011 and 1998 eruptions at Axial and hence cannot be explained by emplacement of the 2015 lava flows on the seafloor. In this study, we investigate several possible explanations for the 2015 temperature anomalies and use a numerical model to test our preferred hypothesis that the temperature increases were caused by the release of a warm, dense brine that had previously been stored in the crust. If our interpretation is correct, this is the first time that the release of a hydrothermal brine has been observed due to a submarine eruption. This observation would have important implications for the salt balance of hydrothermal systems and the fate of brines stored in the subsurface. The observation of the 2015 temperature anomalies and the modeling presented in this study also demonstrate the importance of contemporaneous water column observations to better understand hydrothermal impacts of submarine eruptions.}, issn = {15252027}, doi = {10.1029/2018gc007607}, url = {https://agupubs.onlinelibrary.wiley.com/doi/abs/10.1029/2018GC007607}, author = {Xu, Guangyu and Chadwick, William W. and Wilcock, William S. D. and Bemis, Karen G. and Delaney, John} } @article {RN13, title = {The Ocean Observatories Initiative}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {16-35}, type = {Journal Article}, abstract = {The Ocean Observatories Initiative (OOI) is an integrated suite of instrumented platforms and discrete instruments that measure physical, chemical, geological, and biological properties from the seafloor to the sea surface. The OOI provides data to address large-scale scientific challenges such as coastal ocean dynamics, climate and ecosystem health, the global carbon cycle, and linkages among seafloor volcanism and life. The OOI Cyberinfrastructure currently serves over 250 terabytes of data from the arrays. These data are freely available to users worldwide, changing the way scientists and the broader community interact with the ocean, and permitting ocean research and inquiry at scales of centimeters to kilometers and seconds to decades.}, issn = {10428275}, doi = {10.5670/oceanog.2018.105}, author = {Smith, Leslie and Barth, John and Kelley, Deborah and Plueddemann, Al and Rodero, Ivan and Ulses, Greg and Vardaro, Michael and Weller, Robert} } @article {RN87, title = {Passive acoustic records of seafloor methane bubble streams on the Oregon continental margin}, journal = {Deep Sea Research Part II: Topical Studies in Oceanography}, volume = {150}, year = {2018}, pages = {210-217}, type = {Journal Article}, abstract = {We present acoustic records of methane bubble streams recorded ~10 km southwest of Heceta Bank on the Oregon continental margin using an autonomous hydrophone. The hydrophone was deployed at 1228 m water depth via a Remotely Operated Vehicle (ROV) during the E/V Nautilus expedition (NA072) in June 2016. Bubble sound is produced by detachment of the gas bubble from the end of a tube or conduit which causes the bubble to oscillate, producing a sound signal. Despite persistent ship propeller and ROV noise, the acoustic signature of the overall bubble seep site can be seen in the hydrophone record as a broadband (1.0 {\textendash} 45 kHz) series of short duration (~10{\textendash}20 ms) oscillatory signals that occur in clusters lasting 2{\textendash}3 s. The frequency of an individual bubble{\textquoteright}s oscillation is proportional to the bubble{\textquoteright}s radius; estimates here of bubble radii are consistent with bubble sizes observed in ROV still images. Acoustic signal loss models imply bubble sounds might be recorded over an area of seafloor from ~300 {\textendash} 3.2 {\texttimes} 104 m2. This study represents a first-step in attempting to identify and quantify deep-ocean bubble stream sounds using passive acoustic techniques.}, keywords = {Bubble streams, E/V Nautilus Cruise ID NA072, Gas flux, Methane seep, Passive acoustics}, issn = {0967-0645}, doi = {10.1016/j.dsr2.2018.04.001}, url = {http://www.sciencedirect.com/science/article/pii/S096706451730084X}, author = {Dziak, R. P. and Matsumoto, H. and Embley, R. W. and Merle, S. G. and Lau, T. K. and Baumberger, T. and Hammond, S. R. and Raineault, N.} } @article {RN45, title = {Power from Benthic Microbial Fuel Cells Drives Autonomous Sensors and Acoustic Modems}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {98-103}, type = {Journal Article}, abstract = {Autonomous platforms that support low-power sensors represent one approach to expanding ocean observing. This paper describes a unique autonomous platform designed to deliver long-term sensor measurements from the benthic boundary layer at low cost. The platform, called a Benthic Observer (BeOb), is powered by energy harvested with a benthic microbial fuel cell (BMFC), and it uses an acoustic modem to both store and transmit data organized in daily reports of hourly measurements. A BeOb equipped with sensors to measure dissolved oxygen, temperature, and conductivity ~1 m above the seabed has been active for over 14 months on the Oregon slope at a location within the core of the oxygen minimum zone. During this observation period, the system{\textquoteright}s battery reserves have been kept fully charged by the BMFC. A 90-day time series of sensor data are compared to simultaneous high-frequency measurements at a neighboring Ocean Observatories Initiative cabled Benthic Experiment Package to examine the expected quality and confidence levels for seasonal or annual means of continued measurements. An ocean observing system incorporating arrays of BMFCpowered platforms transmitting to central gateway modems is proposed for future ocean-property monitoring programs. Such arrays may be especially helpful for tracking expansions of ocean oxygen minimum zones.}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.115}, url = {://WOS:000427367300015}, author = {Reimers, C. E. and Wolf, M.} } @article {RN92, title = {Probabilistic Cable Damage Risk Assessment Method for Seafloor Cabled Observatory and Its Application to Hydrothermal Fields}, journal = {Ohki, Takeshi}, volume = {52}, number = {3}, year = {2018}, pages = {138-149(12)}, type = {Journal Article}, abstract = {As part of a recent Japanese governmental project, the government has planned and begun a program to develop a seafloor cabled observatory that facilitates the long-term monitoring of hydrothermal vents and the ecological changes surrounding them. Because commercial cables are typically laid to avoid rough terrain and hydrothermal fields, there is no established method to assess system damage risk for a cabled observatory installed on a hydrothermal field. In this article, we propose a probabilistic cable damage risk assessment method for a seafloor cabled observatory installed on a hydrothermal field. The core concept of our method is the use of probability functions to estimate the system damage risk for the system of a seafloor cabled observatory laid on a defined route. The considered damage factors are potential heat damage risks to the cabled system and damage risks caused by frequent contact between the cable and seafloor. The product of each risk probability represents the total survivability of the system on the route. The proposed method was applied to the Oomuro-hole hydrothermal field on the active submarine Oomuro-dashi volcano, where remotely operated vehicle (ROV) surveys have been performed. The discovered risk factors are organized into a geographic database, and risk value fields are generated. We planned and evaluated several candidate routes that connect a target site for observation to the cabled system terminal unit. Finally, the proposed method derives quantitative system survivability values for the candidate routes and facilitates planning of the layout for a seafloor cabled observatory installed on a hydrothermal field.}, keywords = {Cabled observatory, hydrothermal field, remotely operated vehicle (ROV)}, doi = {10.4031/mtsj.52.3.4}, url = {https://app.dimensions.ai/details/publication/pub.1111829968}, author = {Ohki, Takeshi and Yokobiki, Takashi and Nishida, Shuhei and Tani, Kenichiro and Araki, Eiichiro and Kawaguchi, Katsuyoshi} } @article {RN2, title = {THE RECENT VOLCANIC HISTORY OF AXIAL SEAMOUNT Geophysical Insights into Past Eruption Dynamics with an Eye Toward Enhanced Observations of Future Eruptions}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {114-123}, type = {Journal Article}, abstract = {To understand the processes that form oceanic crust as well as the role of submarine volcanoes in exchanging heat and chemicals with the ocean and in supporting chemosynthetic biological communities, it is essential to study underwater eruptions. The world{\textquoteright}s most advanced underwater volcano observatory{\textemdash}the Ocean Observatories Initiative Cabled Array at Axial Seamount{\textemdash}builds upon ~30 years of sustained geophysical monitoring at this site with autonomous and remote systems. In April 2015, only months after the Cabled Array{\textquoteright}s installation, it recorded an eruption at Axial Seamount, adding to the records of two prior eruptions in 1998 and 2011. Between eruptions, magma recharge is focused beneath the southeast part of the summit caldera, leading to steady inflation and increasing rates of seismicity. During each eruption, the volcano deflates over days to weeks, coincident with high levels of seismicity as a dike is emplaced along one of the volcano{\textquoteright}s rifts and lava erupts on the seafloor. Cabled Array seismic data show that motions on an outward-dipping ring fault beneath the caldera accommodate the inflation and deflation. Eruptions appear to occur at a predictable level of inflation; hence, it should be possible to time deployments of additional cabled and autonomous instrumentation to further enhance observations of the next eruption.}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.117}, url = {://WOS:000427367300017}, author = {Wilcock, W. S. D. and Dziak, R. P. and Tolstoy, M. and Chadwick, W. W. and Nooner, S. L. and Bohnenstiehl, D. R. and Caplan-Auerbach, J. and Waldhauser, F. and Arnulf, A. F. and Baillard, C. and Lau, T. K. and Haxel, J. H. and Tan, Y. J. and Garcia, C. and Levy, S. and Mann, M. E.} } @article {RN28, title = {A regime-dependent retrieval algorithm for near-surface air temperature and specific humidity from multi-microwave sensors}, journal = {Remote Sensing of Environment}, volume = {215}, year = {2018}, pages = {199-216}, type = {Journal Article}, abstract = {Near-surface specific humidity (qa) and air temperature (Ta) over the global ocean are important meteorological variables, but they cannot be retrieved directly from remote sensing. Many efforts have been made to develop algorithms that derive qa and Ta from multisensor microwave and/or infrared observations using in situ measurements as training datasets. However, uncertainty remains large in the resultant qa and Ta retrievals. In this study, 147 moored surface buoys are used to examine how buoy measured qa and Ta are related to satellite microwave brightness temperature (Tb) on the spatial scale from the warm/humid tropics to the cold/dry high latitudes. It is found that the Tb {\textendash} qa and Tb {\textendash} Ta relations are structured along two distinct, near-linear bands, with the primary band in the warm/humid regime and a secondary (weaker) band in the cold/dry regime. The step-like transition (or separation) between the two regimes occurs at 8{\textendash}10 g kg-1 for qa and 14{\textendash}17 {\textdegree}C for Ta. The evidence suggests that one algorithm may not be sufficient to extract qa and Ta from Tb in all regimes. Therefore, a high-latitude enhancement is added to the global algorithm so that the qa and Ta retrievals in the dry/cold regime can be specifically addressed. The new algorithms are applied to 11 microwave sensors, including SSM/I, SSMIS, and AMSU-A, from 1988 to 2016. Based on the 475,717 buoy collocations during the 29-year period, the retrieved qa and Ta have root-mean-square differences of 0.82 g kg-1 and 0.51 {\textdegree}C, respectively. }, keywords = {Microwave passive sensors, Moored surface buoys, Multisensor retrieval, Near-surface air temperature and specific humidity, Retrieval algorithm}, issn = {00344257}, doi = {10.1016/j.rse.2018.06.001}, url = {https://staging-ddpp.dimensions.ai/details/publication/pub.1104605412}, author = {Yu, Lisan and Jin, Xiangze} } @article {RN218, title = {On the Relationship Between the Global Ocean Observing System and the Ocean Observatories Initiative}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {38-41}, type = {Journal Article}, abstract = {The Global Ocean Observing System (GOOS; http://www.goosocean.org) is an international framework for supporting and sustaining the geographically distributed collection of ocean observations designed to benefit science and society. Observations required to guide an evidentiary-​based response by society to environmental change are determined by various international conventions (e.g., United Nations Framework Convention on Climate Change). GOOS, under the Intergovernmental Oceanographic Commission of UNESCO, seeks to respond to the high-level requirement for ocean observations by managing a suite of global networks that collect observations. These networks include, for example, the global array of nearly 4,000 Argo profiling floats, arrays of about 1,250 surface drifters and 300 precision tide gauges, moorings at dozens of key sites around the planet, and repeat hydrographic lines that replicate the sampling of the World Ocean Circulation Experiment about every 10 years (Figure 1).}, doi = {10.5670/oceanog.2018.107}, url = {https://app.dimensions.ai/details/publication/pub.1100958979 https://tos.org/oceanography/assets/docs/31-1_lindstrom.pdf}, author = {Lindstrom, Eric} } @article {RN46, title = {The Role of the Ocean Observatories Initiative in Monitoring the Offshore Earthquake Activity of the Cascadia Subduction Zone}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {104-113}, type = {Journal Article}, abstract = {Geological and historical data indicate that the Cascadia subduction zone last ruptured in a major earthquake in 1700. The timing of the next event is currently impossible to predict, but recent studies of several large subduction zone earthquakes provide tantalizing hints of precursory activity. The seismometers at the Ocean Observatories Initiative (OOI) Slope Base and Southern Hydrate Ridge nodes are well placed to provide new insights into interplate coupling because they are located over a segment of the subduction zone that is nominally locked but that has been relatively active for more than a decade. Since their installation in 2014, 18 earthquakes with magnitudes up to 3.8 have been located by the Pacific Northwest Seismic Network between 44{\textdegree}N and 45{\textdegree}N in the region of the plate boundary thought to be accumulating strain. The OOI seismometers have also detected events that were not reported by the onshore seismic network. Noting that OOI data are available in real time, which is a necessary criterion for routine earthquake monitoring, and that the OOI seismometers generally have lower noise levels than campaign-style ocean bottom seismometers, there would be significant benefit to adding seismometers to existing nodes that are not yet instrumented with seismometers. }, issn = {1042-8275}, doi = {10.5670/oceanog.2018.116}, url = {://WOS:000427367300016}, author = {Trehu, A. M. and Wilcock, W. S. D. and Hilmo, R. and Bodin, P. and Connolly, J. and Roland, E. C. and Braunmiller, J.} } @article {RN81, title = {Satellite detection of an unusual intrusion of salty slope water into a marginal sea: Using SMAP to monitor Gulf of Maine inflows}, journal = {Remote Sensing of Environment}, volume = {217}, year = {2018}, pages = {550-561}, type = {Journal Article}, abstract = {Satellite salinity from the Soil Moisture Active Passive (SMAP) mission and in situ observations are used to diagnose the source of a significant increase in warm and salty surface water entering the Gulf of Maine (GoM) in the winter of 2017{\textendash}2018. SMAP salinity anomaly data indicate that this event was related to a salty feature that moved along the northwestern Atlantic shelf break from near the Grand Banks southwest towards the GoM over eight months before entering the Gulf in December 2017 to January 2018. Satellite altimetry, sea surface salinity, and sea surface temperature data suggest that, before entering the GoM, the salty feature interacted with Gulf Stream meanders and eddies several times, helping to sustain the water mass. It is likely that feature interactions with a warm Gulf Stream meander took place in the fall of 2017, helping to advect high salinity water onto the shelf and then into the GoM as a surface trapped feature in late fall 2017. According to satellite salinity data, this episode led to significant salinification (about 1 psu) in the northeastern GoM. Interior GoM buoy salinity data agree in showing four months of increased GoM salinity of the upper 50 m starting in November 2017. Buoy T/S analyses characterize this surface inflow as modified warm Atlantic slope water, typically seen only below 100 m and previously unobserved at the surface in the 15-year buoy record. This new salty water circulated cyclonically along the GoM coastline and mixed into the deeper Gulf through February 2018. Its intrusion may have also enhanced the cyclonic winter circulation in the Gulf. GoM surface salinity anomalies ended abruptly in early March 2018 coincident with the occurrence of a bomb cyclone and its associated strong upper ocean mixing. }, keywords = {Gulf of Maine, satellite salinity, Sea level, Temperature}, issn = {0034-4257}, doi = {10.1016/j.rse.2018.09.004}, url = {http://www.sciencedirect.com/science/article/pii/S0034425718304152}, author = {Grodsky, Semyon A. and Vandemark, Douglas and Feng, Hui and Levin, Julia} } @article {RN276, title = {Seasonality of Freshwater in the East Greenland Current System From 2014 to 2016}, journal = {Journal of Geophysical Research-Oceans}, volume = {123}, number = {12}, year = {2018}, pages = {8828-8848}, type = {Journal Article}, issn = {2169-9275}, doi = {10.1029/2018JC014511}, author = {Le Bras, I. A. A. and Straneo, F. and Holte, J. and Holliday, N. P.} } @article {RN220, title = {SIDEBAR Accessing OOI Data}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {36-37}, type = {Journal Article}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.106}, author = {Vardaro, M. F. and McDonnell, J.} } @article {RN222, title = {SIDEBAR Get Engaged with the Ocean Observatories Initiative}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {136-137}, type = {Journal Article}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.121}, author = {Ulses, G. A. and Smith, L. M. and Cowles, T. J.} } @article {RN221, title = {SIDEBAR SeaView: Bringing Together an Ocean of Data}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {71-71}, type = {Journal Article}, abstract = {The Ocean Observatories Initiative (OOI) supports a comprehensive information management system for data collected by OOI assets, providing access to a wealth of new information for scientists. But what of those wishing to access data from the region of an OOI research array that is not from OOI assets, perhaps to look at longer term trends from before the launch of OOI, or to build a larger regional context? Despite the excellent work of ocean data repositories, finding, accessing, understanding, and reformatting data for use in a desired visualization or analysis tool remains challenging, especially when data are held in multiple repositories.}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.111}, author = {Stocks, K. and Diggs, S. and Olson, C. and Pham, A. and Arko, R. and Shepherd, A. and Kinkade, D.} } @article {RN301, title = {Structure and Formation of Anticyclonic Eddies in the Iceland Basin}, journal = {Journal of Geophysical Research - Oceans}, volume = {123}, number = {8}, year = {2018}, pages = {5341-5359}, type = {Journal Article}, doi = {10.1029/2018jc013886}, url = {https://app.dimensions.ai/details/publication/pub.1105152134 https://agupubs.onlinelibrary.wiley.com/doi/pdfdirect/10.1029/2018JC013886}, author = {Zhao, Jian and Bower, Amy and Yang, Jiayan and Lin, Xiaopei and Zhou, Chun} } @article {RN8, title = {Structure, Seismicity, and Accretionary Processes at the Hot Spot-Influenced Axial Seamount on the Juan de Fuca Ridge}, journal = {Journal of Geophysical Research: Solid Earth}, volume = {123}, number = {6}, year = {2018}, pages = {4618-4646}, type = {Journal Article}, abstract = {Axial Seamount is the most volcanically active site of the northeast Pacific, and it has been monitored with a growing set of observations and sensors during the last two decades. Accurate imaging of the internal structure of volcanic systems is critical to better understand magma storage processes and to quantify mass and energy transport mechanisms in the crust. To improve the three-dimensional velocity structure of Axial Seamount, we combined 469,891 new traveltime arrivals, from 12 downward extrapolated seismic profiles, with 3,962 existing ocean-bottom-seismometers traveltime arrivals, into a joint tomographic inversion. Our approach reveals two elongated magma reservoirs, with melt fraction up to 65\%, representing an unusually large volume of melt (26{\textendash}60 km3), which is likely the result of enhanced magma supply from the juxtaposition of the Cobb hot spot plume (0.26{\textendash}0.53 m3/s) and the Axial spreading segment (0.79{\textendash}1.06 m3/s). The tomographic model also resolves a subsided caldera floor that provides an effective trap for ponding lava flows, via a {\textquotedblleft}trapdoor{\textquotedblright} mechanism. Our model also shows that Axial{\textquoteright}s extrusive section is thinnest beneath the elevated volcano, where anomalously thick (11 km) oceanic crust is present. We therefore suggest that focused and enhanced melt supply predominantly thickens the crust beneath Axial Seamount through diking accretion and gabbro crystallization. Lastly, we demonstrate that our three-dimensional velocity model provides a more realistic starting point for relocating the local seismicity, better resolving a network of conjugate outward and inward dipping faults beneath the caldera walls.}, keywords = {axial seamount, hot spot, Juan de Fuca ridge, magmatic system, traveltime tomography, volcano}, issn = {21699313}, doi = {10.1029/2017jb015131}, author = {Arnulf, A. F. and Harding, A. J. and Kent, G. M. and Wilcock, W. S. D.} } @article {RN84, title = {Surfzone State Estimation, with Applications to Quadcopter-Based Remote Sensing Data}, journal = {Journal of Atmospheric and Oceanic Technology}, volume = {35}, number = {10}, year = {2018}, pages = {1881-1896}, type = {Journal Article}, abstract = {A one-dimensional variational data assimilation (1DVar) method is presented based on the depth- and time-averaged alongshore-uniform surfzone wave and current equations, for simultaneous estimation of three uncertain variables: bathymetry, incident wave boundary conditions, and bed roughness. The method is validated using twin tests and in situ field observations, and its results are shown to be comparable to those of an existing ensemble-based bathymetry inversion technique. Unlike existing techniques, the ability to simultaneously estimate boundary conditions and bed roughness along with bathymetry also means the 1DVar method can produce full state estimates without the requirement for additional supporting measurements (e.g., direct measurements of the incident waves). A proof-of-concept field application is shown using observations collected from an unmanned quadcopter sensor package that measures surfzone wave height from a fixed-beam lidar range finder, and time-averaged longshore current from particle image velocimetry of drifting surface foam.}, keywords = {Bayesian methods, Coastal flows, Data assimilation, Inverse methods, Numerical analysis/modeling, Variational analysis}, issn = {0739-0572}, doi = {10.1175/JTECH-D-17-0205.1}, url = {https://doi.org/10.1175/JTECH-D-17-0205.1}, author = {Wilson, Gregory and Berezhnoy, Stephen} } @article {RN219, title = {A Tale of Two Eruptions HOW DATA FROM AXIAL SEAMOUNT LED TO A DISCOVERY ON THE EAST PACIFIC RISE}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {124-126}, type = {Journal Article}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.118}, author = {Tolstoy, M. and Wilcock, W. S. D. and Tan, Y. J. and Waldhauser, F.} } @article {RN33, title = {Temporal and Spatial Dynamics of Physical and Biological Properties along the Endurance Array of the California Current Ecosystem}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {80-89}, type = {Journal Article}, abstract = {The coastal margin of the Pacific Northwest of the United States is a highly dynamic and productive region. Here, we use satellite, high-frequency mooring, and glider estimates of biologically relevant physical and optical variables to characterize seasonal patterns and latitudinal and cross-shore gradients in particle concentrations between the Washington and Oregon shelves. Consistent with prior research, we find that the Columbia River exerts a strong seasonal influence on the Washington shelf, but smaller coastal rivers and resuspension processes also appear important in determining particle distributions nearshore during winter across the full study region. We find fluorescence-based measurements of chlorophyll to be similar in magnitude across the two shelves over the time period examined, although the much weaker wind stresses off Washington indicate that processes other than upwelling are important determinants of chlorophyll changes in those areas, as previously suggested. These in situ observations contrast with the overall differences observed from satellite data, which consistently show higher chlorophyll concentrations off the Washington coast. This research suggests that latitudinal differences in chromophoric dissolved organic matter may be a partial explanation for perceived trends in satellite-derived chlorophyll. The observations presented are nascent; maturation of temporal and spatial coverage of OOI data sets will be necessary to more conclusively link physical forcing and biogeochemical responses.}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.113}, url = {://WOS:000427367300013}, author = {Freitas, F. H. and Saldias, G. S. and Goni, M. and Shearman, R. K. and White, A. E.} } @article {RN34, title = {Warm Blobs, Low-Oxygen Events, and an Eclipse THE OCEAN OBSERVATORIES INITIATIVE ENDURANCE ARRAY CAPTURES THEM ALL}, journal = {Oceanography}, volume = {31}, number = {1}, year = {2018}, pages = {90-97}, type = {Journal Article}, abstract = {The Ocean Observatories Initiative (OOI) Endurance Array in the Northeast Pacific off the coasts of Oregon and Washington is designed to measure changes in the ocean on timescales from hours to decades. The Endurance Array is located halfway between the pole and the equator in one of the major coastal upwelling systems on our planet, the California Current System. This area is forced locally by winds, waves, tides, and freshwater inputs from rivers and, more broadly, by large-scale ocean-atmosphere phenomena from both the south, for example, the El Ni{\~n}o-Southern Oscillation, and the north, for example, changes originating in the subarctic Gulf of Alaska. The Endurance Array spans the continental shelf and slope and hosts a variety of platforms and sensors for measuring physical-biogeochemical oceanographic processes. After briefly introducing the unique OOI platforms and range of sensors that make up the Endurance Array, we describe three phenomena with durations spanning hours to years. These include an ocean response to the total eclipse of the Sun on August 21, 2017, the devastating effects of a low-oxygen event off central Oregon, and the appearance of an anomalously warm upper-ocean feature off the Pacific Northwest in recent years.}, issn = {1042-8275}, doi = {10.5670/oceanog.2018.114}, url = {://WOS:000427367300014}, author = {Barth, J. A. and Fram, J. P. and Dever, E. P. and Risien, C. M. and Wingard, C. E. and Collier, R. W. and Kearney, T. D.} } @article {RN4, title = {Circulation, hydrography, and transport over the summit of Axial Seamount, a deep volcano in the Northeast Pacific}, journal = {Journal of Geophysical Research-Oceans}, volume = {122}, number = {7}, year = {2017}, pages = {5404-5422}, type = {Journal Article}, abstract = {A numerical model of ocean flow, hydrography, and transport is used to extrapolate observations of currents and hydrography and infer patterns of material flux in the deep ocean around Axial Seamount, a destination node of NSF{\textquoteright}s Ocean Observatories Initiative{\textquoteright}s Cabled Array. Using an inverse method, the model is made to approximate measured deep ocean flow around this site during a 35 day time period in the year 2002. The model is then used to extract month-long mean patterns and examine smaller-scale spatial and temporal variability around Axial. Like prior observations, model month-long mean currents flow anticyclonically around the seamount{\textquoteright}s summit in toroidal form with maximum speeds at 1500 m depth of 10{\textendash}11 cm/s. As a time mean, the temperature (salinity) anomaly distribution takes the form of a cold (briny) dome above the summit. Passive tracer material continually released at the location of the ASHES vent field exits the caldera primarily through its southern open end before filling the caldera. Once outside the caldera, the tracer circles the summit in clockwise fashion, fractionally reentering the caldera over lower walls at its north end, while gradually bleeding southwestward during the modeled time period into the ambient ocean. A second tracer release experiment using a source of only 2 day duration inside and near the CASM vent field at the northern end of the caldera suggests a residence time of the fluid at that locale of 8{\textendash}9 days.}, issn = {2169-9275}, doi = {10.1002/2016jc012464}, url = {://WOS:000409893600012}, author = {Xu, G. and Lavelle, J. W.} } @article {RN225, title = {An ecosystem-based deep-ocean strategy}, journal = {Science}, volume = {355}, number = {6324}, year = {2017}, pages = {452-454}, type = {Journal Article}, abstract = {Increasing exploration and industrial exploitation of the vast and fragile deep-ocean environment for a wide range of resources (e.g., oil, gas, fisheries, new molecules, and soon, minerals) raises global concerns about potential ecological impacts (1{\textendash}3). Multiple impacts on deep-sea ecosystems (>200 m below sea level; \~{}65\% of the Earth{\textquoteright}s surface is covered by deep ocean) caused by human activities may act synergistically and span extensive areas. Cumulative impacts could eventually cause regime shifts and alter deep-ocean life-support services, such as the biological pump or nutrient recycling (2, 4, 5). Although international law and national legislation largely ignore the deep sea{\textquoteright}s critical role in the functioning and buffering of planetary systems, there are promising developments in support of deep-sea protection at the United Nations and the International Seabed Authority (ISA). We propose a strategy that builds from existing infrastructures to address research and monitoring needs to inform governments and regulators.}, issn = {0036-8075}, doi = {10.1126/science.aah7178}, author = {Danovaro, R. and Aguzzi, J. and Fanelli, E. and Billett, D. and Gjerde, K. and Jamieson, A. and Ramirez-Llodra, E. and Smith, C. R. and Snelgrove, P. V. R. and Thomsen, L. and Van Dover, C. L.} } @article {RN5, title = {Explosive processes during the 2015 eruption of Axial Seamount, as recorded by seafloor hydrophones}, journal = {Geochemistry Geophysics Geosystems}, volume = {18}, number = {4}, year = {2017}, pages = {1761-1774}, type = {Journal Article}, abstract = {Following the installation of the Ocean Observatories Initiative cabled array, the 2015 eruption of Axial Seamount, Juan de Fuca ridge, became the first submarine eruption to be captured in real time by seafloor seismic and acoustic instruments. This eruption also marked the first instance where the entire eruption cycle of a submarine volcano, from the previous eruption in 2011 to the end of the month-long 2015 event, was monitored continuously using autonomous ocean bottom hydrophones. Impulsive sounds associated with explosive lava-water interactions are identified within hydrophone records during both eruptions. Explosions within the caldera are acoustically distinguishable from those occurring in association with north rift lava flows erupting in 2015. Acoustic data also record a series of broadband diffuse events, occurring in the waning phase of the eruption, and are interpreted as submarine Hawaiian explosions. This transition from gas-poor to gas-rich eruptive activity coincides with an increase in water temperature within the caldera and with a decrease in the rate of deflation. The last recorded diffuse events coincide with the end of the eruption, represented by the onset of inflation. All the observed explosion signals couple strongly into the water column, and only weakly into the solid Earth, demonstrating the importance of hydroacoustic observations as a complement to seismic and geodetic studies of submarine eruptions.}, issn = {1525-2027}, doi = {10.1002/2016gc006734}, url = {://WOS:000403478500025}, author = {Caplan-Auerbach, J. and Dziak, R. P. and Haxel, J. and Bohnenstiehl, D. R. and Garcia, C.} } @article {RN223, title = {High-Resolution AUV Mapping and Targeted ROV Observations of Three Historic Lava Flows at Axial Seamount}, journal = {Oceanography}, volume = {30}, number = {4}, year = {2017}, pages = {82-99}, type = {Journal Article}, abstract = {The lava flows produced by eruptions at Axial Seamount in 1998, 2011, and 2015 were mapped at 1 m resolution from autonomous underwater vehicles (AUVs) developed at the Monterey Bay Aquarium Research Institute (MBARI). A portion of the flows erupted in 2011 and 2015 are defined by pre- and post-eruption AUV surveys. Data processing software, also developed at MBARI, precisely coregisters pre- and post-eruption surveys to allow construction of difference maps by subtracting a pre-eruption grid from a post-eruption grid. Such difference maps are key to extracting detailed information about eruptive processes and emplacement of the lava flows. All three eruptions began on the east side of the caldera, and each produced ~25 {\texttimes} 106 m3 of thin channelized flows (with sheet lava channels, lobate lava interiors with pillars, and distal inflated pillow lobes) in the caldera and on the upper south or north rifts. The 1998 and 2011 eruptions propagated down the south rift, and the 2015 eruption propagated down the north rift. The 2011 and 2015 eruptions formed shallow grabens surrounding new non-eruptive open fissures on the east rim of the caldera and produced thick hummocky flows on upper to mid rifts, and the 2011 eruption also produced a thick hummocky flow on the lower south rift. Future eruptions at Axial Seamount will likely follow this pattern, regardless of which rift is the locus of the eruption.}, issn = {1042-8275}, doi = {10.5670/oceanog.2017.426}, author = {Clague, D. A. and Paduan, J. B. and Caress, D. W. and Chadwick, W. W. and Le Saout, M. and Dreyer, B. M. and Portner, R. A.} } @article {RN49, title = {Monitoring networks through multiparty session types}, journal = {Theoretical Computer Science}, volume = {669}, year = {2017}, pages = {33-58}, type = {Journal Article}, abstract = {In large-scale distributed infrastructures, applications are realised through communications among distributed components. The need for methods for assuring safe interactions in such environments is recognized, however the existing frameworks, relying on centralised verification or restricted specification methods, have limited applicability. This paper proposes a new theory of monitored π-calculus with dynamic usage of multiparty session types (MPST), offering a rigorous foundation for safety assurance of distributed components which asynchronously communicate through multiparty sessions. Our theory establishes a framework for semantically precise decentralised run-time enforcement and provides reasoning principles over monitored distributed applications, which complement existing static analysis techniques. We introduce asynchrony through the means of explicit routers and global queues, and propose novel equivalences between networks, that capture the notion of interface equivalence, i.e. equating networks offering the same services to a user. We illustrate our static-dynamic analysis system with an ATM protocol as a running example and justify our theory with results: satisfaction equivalence, local/global safety and transparency, and session fidelity.}, keywords = {Global Type, Local Type, Partial Network, Satisfaction Relation, Session Type}, issn = {0304-3975}, doi = {10.1016/j.tcs.2017.02.009}, url = {://WOS:000397690600003}, author = {Bocchi, L. and Chen, T. C. and Demangeon, R. and Honda, K. and Yoshida, N.} } @article {RN91, title = {The O2/N2 Ratio and CO2 Airborne Southern Ocean Study}, journal = {Bulletin of the American Meteorological Society}, volume = {99}, number = {2}, year = {2017}, pages = {381-402}, type = {Journal Article}, abstract = {The Southern Ocean plays a critical role in the global climate system by mediating atmosphere{\textendash}ocean partitioning of heat and carbon dioxide. However, Earth system models are demonstrably deficient in the Southern Ocean, leading to large uncertainties in future air{\textendash}sea CO2 flux projections under climate warming and incomplete interpretations of natural variability on interannual to geologic time scales. Here, we describe a recent aircraft observational campaign, the O2/N2 Ratio and CO2 Airborne Southern Ocean (ORCAS) study, which collected measurements over the Southern Ocean during January and February 2016. The primary research objective of the ORCAS campaign was to improve observational constraints on the seasonal exchange of atmospheric carbon dioxide and oxygen with the Southern Ocean. The campaign also included measurements of anthropogenic and marine biogenic reactive gases; high-resolution, hyperspectral ocean color imaging of the ocean surface; and microphysical data relevant for understanding and modeling cloud processes. In each of these components of the ORCAS project, the campaign has significantly expanded the amount of observational data available for this remote region. Ongoing research based on these observations will contribute to advancing our understanding of this climatically important system across a range of topics including carbon cycling, atmospheric chemistry and transport, and cloud physics. This article presents an overview of the scientific and methodological aspects of the ORCAS project and highlights early findings.}, issn = {0003-0007}, doi = {10.1175/BAMS-D-16-0206.1}, url = {https://doi.org/10.1175/BAMS-D-16-0206.1}, author = {Stephens, Britton B. and Long, Matthew C. and Keeling, Ralph F. and Kort, Eric A. and Sweeney, Colm and Apel, Eric C. and Atlas, Elliot L. and Beaton, Stuart and Bent, Jonathan D. and Blake, Nicola J. and Bresch, James F. and Casey, Joanna and Daube, Bruce C. and Diao, Minghui and Diaz, Ernesto and Dierssen, Heidi and Donets, Valeria and Gao, Bo-Cai and Gierach, Michelle and Green, Robert and Haag, Justin and Hayman, Matthew and Hills, Alan J. and Hoecker-Mart{\'\i}nez, Mart{\'\i}n S. and Honomichl, Shawn B. and Hornbrook, Rebecca S. and Jensen, Jorgen B. and Li, Rong-Rong and McCubbin, Ian and McKain, Kathryn and Morgan, Eric J. and Nolte, Scott and Powers, Jordan G. and Rainwater, Bryan and Randolph, Kaylan and Reeves, Mike and Schauffler, Sue M. and Smith, Katherine and Smith, Mackenzie and Stith, Jeff and Stossmeister, Gregory and Toohey, Darin W. and Watt, Andrew S.} } @article {RN303, title = {Observed and modeled pathways of the Iceland Scotland Overflow Water in the eastern North Atlantic}, journal = {Progress In Oceanography}, volume = {159}, year = {2017}, pages = {211-222}, type = {Journal Article}, doi = {10.1016/j.pocean.2017.10.003}, url = {https://app.dimensions.ai/details/publication/pub.1092226920}, author = {Zou, Sijia and Lozier, Susan and Zenk, Walter and Bower, Amy and Johns, William} } @article {RN24, title = {Overturning in the Subpolar North Atlantic Program: A New International Ocean Observing System}, journal = {Bulletin of the American Meteorological Society}, volume = {98}, number = {4}, year = {2017}, pages = {737-752}, type = {Journal Article}, abstract = {For decades oceanographers have understood the Atlantic meridional overturning circulation (AMOC) to be primarily driven by changes in the production of deep-water formation in the subpolar and subarctic North Atlantic. Indeed, current Intergovernmental Panel on Climate Change (IPCC) projections of an AMOC slowdown in the twenty-first century based on climate models are attributed to the inhibition of deep convection in the North Atlantic. However, observational evidence for this linkage has been elusive: there has been no clear demonstration of AMOC variability in response to changes in deep-water formation. The motivation for understanding this linkage is compelling, since the overturning circulation has been shown to sequester heat and anthropogenic carbon in the deep ocean. Furthermore, AMOC variability is expected to impact this sequestration as well as have consequences for regional and global climates through its effect on the poleward transport of warm water. Motivated by the need for a mechanistic understanding of the AMOC, an international community has assembled an observing system, Overturning in the Subpolar North Atlantic Program (OSNAP), to provide a continuous record of the transbasin fluxes of heat, mass, and freshwater, and to link that record to convective activity and water mass transformation at high latitudes. OSNAP, in conjunction with the Rapid Climate Change{\textendash}Meridional Overturning Circulation and Heatflux Array (RAPID{\textendash}MOCHA) at 26{\textdegree}N and other observational elements, will provide a comprehensive measure of the three-dimensional AMOC and an understanding of what drives its variability. The OSNAP observing system was fully deployed in the summer of 2014, and the first OSNAP data products are expected in the fall of 2017.}, issn = {0003-0007 1520-0477}, doi = {10.1175/bams-d-16-0057.1}, url = {https://staging-ddpp.dimensions.ai/details/publication/pub.1038223668 http://darchive.mblwhoilibrary.org/bitstream/1912/9015/1/bams-d-16-0057.1.pdf}, author = {Susan Lozier, M. and Bacon, Sheldon and Bower, Amy S. and Cunningham, Stuart A. and Femke de Jong, M. and de Steur, Laura and deYoung, Brad and Fischer, J{\"u}rgen and Gary, Stefan F. and Greenan, Blair J. W. and Heimbach, Patrick and Holliday, Naomi P. and Houpert, Lo{\"\i}c and Inall, Mark E. and Johns, William E. and Johnson, Helen L. and Karstensen, Johannes and Li, Feili and Lin, Xiaopei and Mackay, Neill and Marshall, David P. and Mercier, Herl{\'e} and Myers, Paul G. and Pickart, Robert S. and Pillar, Helen R. and Straneo, Fiammetta and Thierry, Virginie and Weller, Robert A. and Williams, Richard G. and Wilson, Chris and Yang, Jiayan and Zhao, Jian and Zika, Jan D.} } @article {RN19, title = {Thirty-Three Years of Ocean Benthic Warming Along the U.S. Northeast Continental Shelf and Slope: Patterns, Drivers, and Ecological Consequences}, journal = {J Geophys Res Oceans}, volume = {122}, number = {12}, year = {2017}, pages = {9399-9414}, type = {Journal Article}, abstract = {The U.S. Northeast Continental Shelf is experiencing rapid warming, with potentially profound consequences to marine ecosystems. While satellites document multiple scales of spatial and temporal variability on the surface, our understanding of the status, trends, and drivers of the benthic environmental change remains limited. We interpolated sparse benthic temperature data along the New England Shelf and upper Slope using a seasonally dynamic, regionally specific multiple linear regression model that merged in situ and remote sensing data. The statistical model predicted nearly 90\% of the variability of the data, resulting in a synoptic time series spanning over three decades from 1982 to 2014. Benthic temperatures increased throughout the domain, including in the Gulf of Maine. Rates of benthic warming ranged from 0.1 to 0.4{\textdegree}C per decade, with fastest rates occurring in shallow, nearshore regions and on Georges Bank, the latter exceeding rates observed in the surface. Rates of benthic warming were up to 1.6 times faster in winter than the rest of the year in many regions, with important implications for disease occurrence and energetics of overwintering species. Drivers of warming varied over the domain. In southern New England and the mid-Atlantic shallow Shelf regions, benthic warming was tightly coupled to changes in SST, whereas both regional and basin-scale changes in ocean circulation affect temperatures in the Gulf of Maine, the Continental Shelf, and Georges Banks. These results highlight data gaps, the current feasibility of prediction from remotely sensed variables, and the need for improved understanding on how climate may affect seasonally specific ecological processes.}, issn = {2169-9275 (Print) 2169-9275 (Linking)}, doi = {10.1002/2017JC012953}, url = {https://www.ncbi.nlm.nih.gov/pubmed/29497591}, author = {Kavanaugh, M. T. and Rheuban, J. E. and Luis, K. M. A. and Doney, S. C.} } @article {RN224, title = {VOLCANOLOGY Vulcan rule beneath the sea}, journal = {Nature Geoscience}, volume = {10}, number = {4}, year = {2017}, pages = {251-252}, type = {Journal Article}, abstract = {Over 70\% of the volcanism on Earth occurs beneath an ocean veil. Now, robotic- and fibre-optic-based technologies are beginning to reveal this deep environment and identify subaqueous volcanoes as rich sources of sulfur, carbon dioxide and life.}, issn = {1752-0894}, doi = {10.1038/ngeo2929}, author = {Kelley, D.} } @article {RN51, title = {Diffuse venting at the ASHES hydrothermal field: Heat flux and tidally modulated flow variability derived from in situ time-series measurements}, journal = {Geochemistry Geophysics Geosystems}, volume = {17}, number = {4}, year = {2016}, pages = {1435-1453}, type = {Journal Article}, abstract = {Time-series measurements of diffuse exit-fluid temperature and velocity collected with a new, deep-sea camera, and temperature measurement system, the Diffuse Effluent Measurement System (DEMS), were examined from a fracture network within the ASHES hydrothermal field located in the caldera of Axial Seamount, Juan de Fuca Ridge. The DEMS was installed using the HOV Alvin above a fracture near the Phoenix vent. The system collected 20 s of 20 Hz video imagery and 24 s of 1 Hz temperature measurements each hour between 22 July and 2 August 2014. Fluid velocities were calculated using the Diffuse Fluid Velocimetry (DFV) technique. Over the \~{}12 day deployment, median upwelling rates and mean fluid temperature anomalies ranged from 0.5 to 6 cm/s and 0{\textdegree}C to \~{}6.5{\textdegree}C above ambient, yielding a heat flux of 0.29 {\textpm} 0.22 MW m-2 and heat output of 3.1{\textpm} 2.5 kW. Using a photo mosaic to measure fracture dimensions, the total diffuse heat output from cracks across ASHES field is estimated to be 2.05 {\textpm} 1.95 MW. Variability in temperatures and velocities are strongest at semidiurnal periods and show significant coherence with tidal height variations. These data indicate that periodic variability near Phoenix vent is modulated both by tidally controlled bottom currents and seafloor pressure, with seafloor pressures being the dominant influence. These results emphasize the importance of local permeability on diffuse hydrothermal venting at mid-ocean ridges and the need to better quantify heat flux associated with young oceanic crust.}, issn = {1525-2027}, doi = {10.1002/2015gc006144}, url = {://WOS:000379523900012}, author = {Mittelstaedt, E. and Fornari, D. J. and Crone, T. J. and Kinsey, J. and Kelley, D. and Elend, M.} } @article {RN228, title = {Drift-corrected seafloor pressure observations of vertical deformation at Axial Seamount 2013{\textendash}2014}, journal = {Earth and Space Science}, volume = {3}, number = {9}, year = {2016}, pages = {381-385}, type = {Journal Article}, abstract = {Axial Seamount on the Juan de Fuca Ridge is a site of ongoing volcanic activity. The vertical component of the deformation can be observed with ambient seawater pressure gauges, which have excellent short-term resolution. However, pressure gauge drift adds additional and significant uncertainty in estimates of long-period deformation; drift rates equivalent to 20{\textendash}30 cm/yr have been observed. One way to circumvent gauge drift is to make differential pressure measurements relative to a distant and presumably stable seafloor reference site. Such measurements require a remotely operated vehicle and can only be made infrequently. Another approach is to incorporate a piston gauge calibrator in the seafloor pressure recorder to generate an in situ reference pressure that, when periodically applied to the drift-susceptible gauge, can be used to determine and remove gauge drift from the time series. We constructed a self-calibrating pressure recorder and deployed it at Axial Seamount in September 2013. The drift-corrected record from that deployment revealed an uplift of the volcano summit of 60 cm over 17 months.}, issn = {2333-5084}, doi = {https://doi.org/10.1002/2016EA000190}, url = {https://doi.org/10.1002/2016EA000190}, author = {Sasagawa, G. and Cook, M. J. and Zumberge, M. A.} } @article {RN7, title = {Inflation-predictable behavior and co-eruption deformation at Axial Seamount}, journal = {Science}, volume = {354}, number = {6318}, year = {2016}, pages = {1399-1403}, type = {Journal Article}, abstract = {Deformation of the ground surface at active volcanoes provides information about magma movements at depth. Improved seafloor deformation measurements between 2011 and 2015 documented a fourfold increase in magma supply and confirmed that Axial Seamount{\textquoteright}s eruptive behavior is inflation-predictable, probably triggered by a critical level of magmatic pressure. A 2015 eruption was successfully forecast on the basis of this deformation pattern and marked the first time that deflation and tilt were captured in real time by a new seafloor cabled observatory, revealing the timing, location, and volume of eruption-related magma movements. Improved modeling of the deformation suggests a steeply dipping prolate-spheroid pressure source beneath the eastern caldera that is consistent with the location of the zone of highest melt within the subcaldera magma reservoir determined from multichannel seismic results.}, issn = {1095-9203 (Electronic) 0036-8075 (Linking)}, doi = {10.1126/science.aah4666}, url = {https://www.ncbi.nlm.nih.gov/pubmed/27980205}, author = {Nooner, S. L. and Chadwick, W. W., Jr.} } @article {RN35, title = {Intraseasonal Cross-Shelf Variability of Hypoxia along the Newport, Oregon, Hydrographic Line}, journal = {Journal of Physical Oceanography}, volume = {46}, number = {7}, year = {2016}, pages = {2219-2238}, type = {Journal Article}, abstract = {Observations of hypoxia, dissolved oxygen (DO) concentrations < 1.4 ml L-1, off the central Oregon coast vary in duration and spatial extent throughout each upwelling season. Underwater glider measurements along the Newport hydrographic line (NH-Line) reveal cross-shelf DO gradients at a horizontal resolution nearly 30 times greater than previous ship-based station sampling. Two prevalent hypoxic locations are identified along the NH-Line, as is a midshelf region with less severe hypoxia north of Stonewall Bank. Intraseasonal cross-shelf variability is investigated with 10 sequential glider lines and a midshelf mooring time series during the 2011 upwelling season. The cross-sectional area of hypoxia observed in the glider lines ranges from 0 to 1.41 km2. The vertical extent of hypoxia in the water column agrees well with the bottom mixed layer height. Midshelf mooring water velocities show that cross-shelf advection cannot account for the increase in outer-shelf hypoxia observed in the glider sequence. This change is attributed to an along-shelf DO gradient of -0.72 ml L-1 over 2.58 km or 0.28 ml L-1 km-1. In early July of the 2011 upwelling season, near-bottom cross-shelf currents reverse direction as an onshore flow at 30-m depth is observed. This shoaling of the return flow depth throughout the season, as the equatorward coastal jet moves offshore, results in a more retentive near-bottom environment more vulnerable to hypoxia. Slope Burger numbers calculated across the season do not reconcile this return flow depth change, providing evidence that simplified two-dimensional upwelling model assumptions do not hold in this location.}, keywords = {Circulation/Dynamics, Coastal flows, Upwelling/downwelling}, issn = {0022-3670}, doi = {10.1175/Jpo-D-15-0119.1}, author = {Adams, K. A. and Barth, J. A. and Shearman, R. K.} } @article {RN11, title = {New insights into magma plumbing along rift systems from detailed observations of eruptive behavior at Axial volcano}, journal = {Geophysical Research Letters}, volume = {43}, number = {24}, year = {2016}, pages = {12423-12427}, type = {Journal Article}, abstract = {The magma reservoir in geophysical volcano plumbing models is often modeled as a simple geometric volume, filled with magma of uniform properties. However, the constraints on reservoir size and magma properties in volcano roots are typically indirect and poor. Axial Seamount, a volcano at a depth of about 1500 m on the Juan de Fuca mid-oceanic ridge in the Pacific Ocean, has both high-resolution seismic images of its subsurface magma and detailed results from monitoring of its most recent eruption and associated seismicity and ground deformation. The 2015 eruption at Axial Seamount is the best monitored submarine eruption so far because of observations made possible by the Ocean Observatories Initiative, and seismic imaging of magma at this volcano is better than in most other environments because of advanced analysis of extensive seismic reflection profiling at sea and the relatively simple volcano structure. This allows new understanding compared to findings from earlier observations from monitored rifting episodes on land. Geophysical magma plumbing models, in general, may need to allow for more complexities, namely, spatial heterogeneities in magma composition, melt content, and location of major volume changes within a single magma dominated crustal volume during eruptions.}, issn = {0094-8276}, doi = {10.1002/2016gl071884}, url = {://WOS:000392741900015}, author = {Sigmundsson, F.} } @article {RN36, title = {Optics of the offshore Columbia River plume from glider observations and satellite imagery}, journal = {Journal of Geophysical Research: Oceans}, volume = {121}, number = {4}, year = {2016}, pages = {2367-2384}, type = {Journal Article}, abstract = {The Columbia River (CR) is the largest source of freshwater along the U.S. Pacific coast. The resultant plume is often transported southward and offshore forming a large buoyant feature off Oregon and northern California in spring-summer{\textemdash}the offshore CR plume. Observations from autonomous underwater gliders and Moderate Resolution Imaging Spectroradiometer (MODIS) satellite imagery are used to characterize the optics of the offshore CR plume off Newport, Oregon. Vertical sections, under contrasting river flow conditions, reveal a low-salinity and warm surface layer of \~{}20{\textendash}25 m (fresher in spring and warmer in summer), high Colored Dissolved Organic Matter (CDOM) concentration, and backscatter, and associated with the base of the plume high chlorophyll fluorescence. Plume characteristics vary in the offshore direction as the warm and fresh surface layer thickens progressively to an average 30{\textendash}40 m of depth 270{\textendash}310 km offshore; CDOM, backscatter, and chlorophyll fluorescence decrease in the upper 20 m and increase at subsurface levels (30{\textendash}50 m depth). MODIS normalized water-leaving radiance (nLw(λ)) spectra for CR plume cases show enhanced water-leaving radiance at green bands (as compared to no-CR plume cases) up to \~{}154 km from shore. Farther offshore, the spectral shapes for both cases are very similar, and consequently, a contrasting color signature of low-salinity plume water is practically imperceptible from ocean color remote sensing. Empirical algorithms based on multivariate regression analyses of nLw(λ) plus SST data produce more accurate results detecting offshore plume waters than previous studies using single visible bands (e.g., adg(412) or nLw(555)).}, issn = {21699275}, doi = {10.1002/2015jc011431}, url = {https://staging-ddpp.dimensions.ai/details/publication/pub.1044838771}, author = {Sald{\'\i}as, Gonzalo S. and Kipp Shearman, R. and Barth, John A. and Tufillaro, Nicholas} } @article {siegel_prediction_2016, title = {Prediction of the Export and Fate of Global Ocean Net Primary Production: The EXPORTS Science Plan}, journal = {Frontiers in Marine Science}, volume = {3}, year = {2016}, abstract = {Ocean ecosystems play a critical role in the Earth{\textquoteright}s carbon cycle and the quantification of their impacts for both present conditions and for predictions into the future remains one of the greatest challenges in oceanography. The goal of the EXport Processes in the Ocean from Remote Sensing (EXPORTS) Science Plan is to develop a predictive understanding of the export and fate of global ocean net primary production (NPP) and its implications for present and future climates. The achievement of this goal requires a quantification of the mechanisms that control the export of carbon from the euphotic zone as well as its fate in the underlying {\textquotedblleft}twilight zone{\textquotedblright} where some fraction of exported carbon will be sequestered in the ocean{\textquoteright}s interior on time scales of months to millennia. Here we present a measurement/synthesis/modeling framework aimed at quantifying the fates of upper ocean NPP and its impacts on the global carbon cycle based upon the EXPORTS Science Plan. The proposed approach will diagnose relationships among the ecological, biogeochemical, and physical oceanographic processes that control carbon cycling across a range of ecosystem and carbon cycling states leading to advances in satellite diagnostic and numerical prognostic models. To collect these data, a combination of ship and robotic field sampling, satellite remote sensing, and numerical modeling is proposed which enables the sampling of the many pathways of NPP export and fates. This coordinated, process-oriented approach has the potential to foster new insights on ocean carbon cycling that maximizes its societal relevance through the achievement of research goals of many international research agencies and will be a key step toward our understanding of the Earth as an integrated system.}, issn = {2296-7745}, doi = {10.3389/fmars.2016.00022}, url = {https://www.frontiersin.org/articles/10.3389/fmars.2016.00022}, author = {Siegel, David A. and Buesseler, Ken O. and Behrenfeld, Michael J. and Benitez-Nelson, Claudia R. and Boss, Emmanuel and Brzezinski, Mark A. and Burd, Adrian and Carlson, Craig A. and D{\textquoteright}Asaro, Eric A. and Doney, Scott C. and Perry, Mary J. and Stanley, Rachel H. R. and Steinberg, Deborah K.} } @article {RN6, title = {Seismic constraints on caldera dynamics from the 2015 Axial Seamount eruption}, journal = {Science}, volume = {354}, number = {6318}, year = {2016}, pages = {1395-1399}, type = {Journal Article}, abstract = {Seismic observations in volcanically active calderas are challenging. A new cabled observatory atop Axial Seamount on the Juan de Fuca ridge allows unprecedented real-time monitoring of a submarine caldera. Beginning on 24 April 2015, the seismic network captured an eruption that culminated in explosive acoustic signals where lava erupted on the seafloor. Extensive seismic activity preceding the eruption shows that inflation is accommodated by the reactivation of an outward-dipping caldera ring fault, with strong tidal triggering indicating a critically stressed system. The ring fault accommodated deflation during the eruption and provided a pathway for a dike that propagated south and north beneath the caldera{\textquoteright}s east wall. Once north of the caldera, the eruption stepped westward, and a dike propagated along the extensional north rift.}, issn = {1095-9203 (Electronic) 0036-8075 (Linking)}, doi = {10.1126/science.aah5563}, url = {https://www.ncbi.nlm.nih.gov/pubmed/27980204}, author = {Wilcock, W. S. and Tolstoy, M. and Waldhauser, F. and Garcia, C. and Tan, Y. J. and Bohnenstiehl, D. R. and Caplan-Auerbach, J. and Dziak, R. P. and Arnulf, A. F. and Mann, M. E.} } @article {RN50, title = {Strong winter cooling over the Irminger Sea in winter 2014-2015, exceptional deep convection, and the emergence of anomalously low SST}, journal = {Geophysical Research Letters}, volume = {43}, number = {13}, year = {2016}, pages = {7106-7113}, type = {Journal Article}, abstract = {Deep convection is presumed to be vital for the North Atlantic Meridional Overturning Circulation, even though observational evidence for the link remains inconclusive. Modeling studies have suggested that convection will weaken as a result of enhanced freshwater input. The emergence of anomalously low sea surface temperature in the subpolar North Atlantic has led to speculation that this process is already at work. Here we show that strong atmospheric forcing in the winter of 2014{\textendash}2015, associated with a high North Atlantic Oscillation (NAO) index, produced record mixed layer depths in the Irminger Sea. Local mixing removed the stratification of the upper 1400 m and ventilated the basin to middepths resembling a state similar to the mid-1990s when a positive NAO also prevailed. We show that the strong local atmospheric forcing is predominantly responsible for the negative sea surface temperature anomalies observed in the subpolar North Atlantic in 2015 and that there is no evidence of permanently weakened deep convection.}, issn = {00948276}, doi = {10.1002/2016gl069596}, author = {de Jong, Marieke Femke and de Steur, Laura} } @article {RN227, title = {Time-series measurements of bubble plume variability and water column methane distribution above Southern Hydrate Ridge, Oregon}, journal = {Geochemistry, Geophysics, Geosystems}, volume = {17}, number = {3}, year = {2016}, pages = {1182-1196}, type = {Journal Article}, abstract = {An estimated 500{\textendash}2500 gigatons of methane carbon is sequestered in gas hydrate at continental margins and some of these deposits are associated with overlying methane seeps. To constrain the impact that seeps have on methane concentrations in overlying ocean waters and to characterize the bubble plumes that transport methane vertically into the ocean, water samples and time-series acoustic images were collected above Southern Hydrate Ridge (SHR), a well-studied hydrate-bearing seep site \~{}90 km west of Newport, Oregon. These data were coregistered with robotic vehicle observations to determine the origin of the seeps, the plume rise heights above the seafloor, and the temporal variability in bubble emissions. Results show that the locations of seep activity and bubble release remained unchanged over the 3 year time-series investigation, however, the magnitude of gas release was highly variable on hourly time scales. Bubble plumes were detected to depths of 320{\textendash}620 m below sea level (mbsl), in several cases exceeding the upper limit of hydrate stability by \~{}190 m. For the first time, sustained gas release was imaged at the Pinnacle site and in-between the Pinnacle and the Summit area of venting, indicating that the subseafloor transport of fluid and gas is not restricted to the Summit at SHR, requiring a revision of fluid-flow models. Dissolved methane concentrations above background levels from 100 to 300 mbsl are consistent with long-term seep gas transport into the upper water column, which may lead to the build-up of seep-derived carbon in regional subsurface waters and to increases in associated biological activity.}, issn = {1525-2027}, doi = {https://doi.org/10.1002/2016GC006250}, url = {https://doi.org/10.1002/2016GC006250}, author = {Philip, Brendan T. and Denny, Alden R. and Solomon, Evan A. and Kelley, Deborah S.} } @article {RN226, title = {Voluminous eruption from a zoned magma body after an increase in supply rate at Axial Seamount}, journal = {Geophysical Research Letters}, volume = {43}, number = {23}, year = {2016}, pages = {12,063-12,070}, type = {Journal Article}, abstract = {Axial Seamount is the best monitored submarine volcano in the world, providing an exceptional window into the dynamic interactions between magma storage, transport, and eruption processes in a mid-ocean ridge setting. An eruption in April 2015 produced the largest volume of erupted lava since monitoring and mapping began in the mid-1980s after the shortest repose time, due to a recent increase in magma supply. The higher rate of magma replenishment since 2011 resulted in the eruption of the most mafic lava in the last 500{\textendash}600 years. Eruptive fissures at the volcano summit produced pyroclastic ash that was deposited over an area of at least 8 km2. A systematic spatial distribution of compositions is consistent with a single dike tapping different parts of a thermally and chemically zoned magma reservoir that can be directly related to previous multichannel seismic-imaging results.}, issn = {0094-8276}, doi = {https://doi.org/10.1002/2016GL071327}, url = {https://doi.org/10.1002/2016GL071327}, author = {Chadwick Jr, W. W. and Paduan, J. B. and Clague, D. A. and Dreyer, B. M. and Merle, S. G. and Bobbitt, A. M. and Caress, D. W. and Philip, B. T. and Kelley, D. S. and Nooner, S. L.} } @article {RN38, title = {Air-sea CO2 fluxes and the controls on ocean surface pCO(2) seasonal variability in the coastal and open-ocean southwestern Atlantic Ocean: a modeling study}, journal = {Biogeosciences}, volume = {12}, number = {19}, year = {2015}, pages = {5793-5809}, type = {Journal Article}, abstract = {We use an eddy-resolving, regional ocean biogeochemical model to investigate the main variables and processes responsible for the climatological spatio-temporal variability of pCO2 and the air-sea CO2 fluxes in the southwestern Atlantic Ocean. Overall, the region acts as a sink of atmospheric CO2 south of 30{\textdegree} S, and is close to equilibrium with the atmospheric CO2 to the north. On the shelves, the ocean acts as a weak source of CO2, except for the mid/outer shelves of Patagonia, which act as sinks. In contrast, the inner shelves and the low latitude open ocean of the southwestern Atlantic represent source regions. Observed nearshore-to-offshore and meridional pCO2 gradients are well represented by our simulation. A sensitivity analysis shows the importance of the counteracting effects of temperature and dissolved inorganic carbon (DIC) in controlling the seasonal variability of pCO2. Biological production and solubility are the main processes regulating pCO2, with biological production being particularly important on the shelves. The role of mixing/stratification in modulating DIC, and therefore surface pCO2, is shown in a vertical profile at the location of the Ocean Observatories Initiative (OOI) site in the Argentine Basin (42{\textdegree} S, 42{\textdegree} W).}, issn = {1726-4170}, doi = {10.5194/bg-12-5793-2015}, author = {Arruda, R. and Calil, P. H. R. and Bianchi, A. A. and Doney, S. C. and Gruber, N. and Lima, I. and Turi, G.} } @article {RN52, title = {Anomalous Near-Surface Low-Salinity Pulses off the Central Oregon Coast}, journal = {Sci Rep}, volume = {5}, year = {2015}, pages = {17145}, type = {Journal Article}, abstract = {From mid-May to August 2011, extreme runoff in the Columbia River ranged from 14,000 to over 17,000 m(3)/s, more than two standard deviations above the mean for this period. The extreme runoff was the direct result of both melting of anomalously high snowpack and rainfall associated with the 2010-2011 La Ni{\~n}a. The effects of this increased freshwater discharge were observed off Newport, Oregon, 180 km south of the Columbia River mouth. Salinity values as low as 22, nine standard deviations below the climatological value for this period, were registered at the mid-shelf. Using a network of ocean observing sensors and platforms, it was possible to capture the onshore advection of the Columbia River plume from the mid-shelf, 20 km offshore, to the coast and eventually into Yaquina Bay (Newport) during a sustained wind reversal event. Increased freshwater delivery can influence coastal ocean ecosystems and delivery of offshore, river-influenced water may influence estuarine biogeochemistry.}, issn = {2045-2322 (Electronic) 2045-2322 (Linking)}, doi = {10.1038/srep17145}, url = {https://www.ncbi.nlm.nih.gov/pubmed/26607750}, author = {Mazzini, P. L. and Risien, C. M. and Barth, J. A. and Pierce, S. D. and Erofeev, A. and Dever, E. P. and Kosro, P. M. and Levine, M. D. and Shearman, R. K. and Vardaro, M. F.} } @article {RN53, title = {Characterizing Complex Marine Systems and Technology Using Visualized Vocabularies}, journal = {Marine Technology Society Journal}, volume = {49}, number = {4}, year = {2015}, pages = {53-63}, type = {Journal Article}, abstract = {The next decade will usher in significant changes in ocean observational infrastructure and how students engage with marine sciences content. Faced with the challenge of helping undergraduate students make sense of very complicated marine systems, a computer sciences-based organizational structure (i.e., ontology) has been employed to characterize the Ocean Observatories Initiative (OOI). Five interlinked vocabularies that include terms, descriptions, and images define the overall system from high-level science themes to specialized data products. Given the importance of visual representations in learning, particularly for novices, an associated interactive tool called the {\textquotedblleft}Vocabulary Navigator{\textquotedblright} has been developed. Created in tandem, the design of the vocabularies and their visualizer is based on principles related to the needs of the target audience such as placing information in a broader context and promoting self-directed discovery. Overall, this effort has resulted in not only innovative online resources for learning about the OOI but also, perhaps more importantly, valuable {\textquotedblleft}lessons learned{\textquotedblright} and transferable software that could be used by other marine technology endeavors. }, keywords = {marine technology, ocean observing, ontology, vocabulary}, issn = {0025-3324}, doi = {10.4031/Mtsj.49.4.2}, url = {://WOS:000361344000010}, author = {deCharon, A. and Smith, L. M. and Companion, C.} } @article {RN16, title = {Dynamics of the direct intrusion of Gulf Stream ring water onto the Mid-Atlantic Bight shelf}, journal = {Geophysical Research Letters}, volume = {42}, number = {18}, year = {2015}, pages = {7687-7695}, type = {Journal Article}, abstract = {Onshore intrusions of offshore waters onto the Mid-Atlantic Bight shelf can greatly affect shelf circulation, biogeochemistry, and fisheries. Previous studies have concentrated on onshore intrusions of slope water. Here we present a direct intrusion of Gulf Stream warm-core ring water onto the shelf representing a previously unknown exchange process at the shelfbreak. Impingement of warm-core rings at the shelfbreak generates along-isobath intrusions that grow like Pinocchio{\textquoteright}s nose, extending hundreds of kilometers to the southwest. By combining satellite and Ocean Observatory Initiative Pioneer Array data and idealized numerical simulations, we discover that the intrusion results from topographically induced vorticity variation of the ring water, rather than from entrainment of the shelfbreak frontal jet. This intrusion of the Gulf Stream ring water has important biogeochemical implications and could facilitate migration of marine species across the shelfbreak barrier and transport low-nutrient surface Gulf Stream ring water to the otherwise productive shelfbreak region. }, issn = {0094-8276}, doi = {10.1002/2015gl065530}, url = {://WOS:000363412400056}, author = {Zhang, W. F. G. and Gawarkiewicz, G. G.} } @article {RN12, title = {An Inductive Charging and Real-Time Communications System for Profiling Moorings}, journal = {Journal of Atmospheric and Oceanic Technology}, volume = {32}, number = {12}, year = {2015}, pages = {2243-2252}, type = {Journal Article}, abstract = {This paper describes a system for providing power and communications to moored profiling vehicles. A McLane Moored Profiler (MP) was equipped with a rechargeable battery pack and an inductive charging system to allow it to move periodically to a charging dock at the top of a subsurface mooring. Power was provided from a large bank of alkaline batteries housed in two 0.94-m steel spheres. Data were transferred inductively from the profiler to a mooring controller, and from there back to shore via radio and Iridium satellite modems housed in a small surface communications float on an {\textquotedblleft}L{\textquotedblright} tether. An acoustic modem provided backup communications to a nearby ship in the event of loss or damage to the surface float. The system was tested in a 180-m-deep fjord (Puget Sound, Washington) and at Station ALOHA (A Long-Term Oligotrophic Habitat Assessment), a 4748-m-deep open-ocean location north of Hawaii. Basic functionality of the system was demonstrated, with the profiler repeatedly recharging at about 225 W (with an overall efficiency of about 70\%). Data were relayed back to shore via Iridium and to a nearby ship via the radio and acoustic modems. The system profiled flawlessly for the entire 6-week test in Puget Sound, but charging at the deep site stopped after only 9 days in the deep-ocean deployment owing to damage to the charging station, possibly by surface wave action.}, keywords = {Observational techniques and algorithms, Profilers; oceanic}, issn = {0739-0572}, doi = {10.1175/Jtech-D-15-0103.1}, author = {Alford, M. H. and McGinnis, T. and Howe, B. M.} } @article {RN54, title = {Practical interruptible conversations: distributed dynamic verification with multiparty session types and Python}, journal = {Formal Methods in System Design}, volume = {46}, number = {3}, year = {2015}, pages = {197-225}, type = {Journal Article}, abstract = {The rigorous and comprehensive verification of communication-based software is an important engineering challenge in distributed systems. Drawn from our industrial collaborations (Ocean Observatories Initative, http://www.oceanobservatories.org/, JBoss Savara Project, http://www.jboss.org/savara) on Scribble, a choreography description language based on multiparty session types, and its theoretical foundations (Honda et al., in POPL, pp 273{\textendash}284, 2008), this article proposes a dynamic verification framework for structured interruptible conversation programming. We first present our extension of Scribble to support the specification of asynchronously interruptible conversations. We then implement a concise API for conversation programming with interrupts in Python that enables session types properties to be dynamically verified for distributed processes. Finally, we expose the underlying theory of our interrupt mechanism, studying its syntax and semantics, its integration in MPST theory and proving the correctness of our design. Our framework ensures the global safety of a system in the presence of asynchronous interrupts through independent runtime monitoring of each endpoint, checking the conformance of the local execution trace to the specified protocol. The usability of our framework for describing and verifying choreographic communications has been tested by integration into the large scientific cyberinfrastructure developed by the Ocean Observatories Initiative. Asynchronous interrupts have proven expressive enough to represent and verify their main classes of communication patterns, including asynchronous streaming and various timeout-based protocols, without introducing any implicit synchronisations. Benchmarks show conversation programming and monitoring can be realised with little overhead.}, keywords = {Distributed systems, Python, Runtime monitoring, Session types}, issn = {0925-9856}, doi = {10.1007/s10703-014-0218-8}, url = {://WOS:000360940700001}, author = {Demangeon, R. and Honda, K. and Hu, R. and Neykova, R. and Yoshida, N.} } @article {RN231, title = {THE CASCADIA INITIATIVE A Sea Change In Seismological Studies of Subduction Zones}, journal = {Oceanography}, volume = {27}, number = {2}, year = {2014}, pages = {138-150}, type = {Journal Article}, abstract = {Increasing public awareness that the Cascadia subduction zone in the Pacific Northwest is capable of great earthquakes (magnitude 9 and greater) motivates the Cascadia Initiative, an ambitious onshore/offshore seismic and geodetic experiment that takes advantage of an amphibious array to study questions ranging from megathrust earthquakes, to volcanic arc structure, to the formation, deformation and hydration of the Juan De Fuca and Gorda Plates. Here, we provide an overview of the Cascadia Initiative, including its primary science objectives, its experimental design and implementation, and a preview of how the resulting data are being used by a diverse and growing scientific community. The Cascadia Initiative also exemplifies how new technology and community-based experiments are opening up frontiers for marine science. The new technology{\textemdash}shielded ocean bottom seismometers{\textemdash}is allowing more routine investigation of the source zone of megathrust earthquakes, which almost exclusively lies offshore and in shallow water. The Cascadia Initiative offers opportunities and accompanying challenges to a rapidly expanding community of those who use ocean bottom seismic data.}, issn = {1042-8275}, doi = {10.5670/oceanog.2014.49}, author = {Toomey, D. R. and Allen, R. M. and Barclay, A. H. and Bell, S. W. and Bromirski, P. D. and Carlson, R. L. and Chen, X. W. and Collins, J. A. and Dziak, R. P. and Evers, B. and Forsyth, D. W. and Gerstoft, P. and Hooft, E. E. E. and Livelybrooks, D. and Lodewyk, J. A. and Luther, D. S. and McGuire, J. J. and Schwartz, S. Y. and Tolstoy, M. and Trehu, A. M. and Weirathmueller, M. and Wilcock, W. S. D.} } @article {RN37, title = {Dynamics of the benthic boundary layer and seafloor contributions to oxygen depletion on the Oregon inner shelf}, journal = {Continental Shelf Research}, volume = {84}, year = {2014}, pages = {93-106}, type = {Journal Article}, abstract = { Outline Highlights Abstract Keywords 1. Introduction 2. Material and methods 3. Results 4. Discussion Acknowledgements Appendix A. Supplementary materials References Figures (11) Fig. 1. Bathymetric and multibeam backscatter map of study site (prepared by C Fig. 2. Digital images of seafloor taken by BOXER camera system in (A) September 2009{\textellipsis} Fig. 3. Stacked measurements of (A) chlorophyll-α and phaeophytin-α contents and (B){\textellipsis} Fig. 4. Sediment formation factor (FF) and O2 microprofiles measured in situ Fig. 5. EC time-series data from April 2009 with date and local time along the top{\textellipsis} Fig. 6. EC time-series data from June 2009 Tables (3) Table 1 Table 2 Table 3 Extras (1) Supplementary material Elsevier Continental Shelf Research Volume 84, 1 August 2014, Pages 93-106 Continental Shelf Research Research papers Dynamics of the benthic boundary layer and seafloor contributions to oxygen depletion on the Oregon inner shelf Author links open overlay panelKristinaMcCann-GrosvenorClare E.ReimersRhea D.Sanders https://doi.org/10.1016/j.csr.2014.05.010Get rights and content Highlights {\textbullet} Eddy correlation O2 fluxes were measured in 2009 at a 30 m site off Newport, OR. {\textbullet} High flux contributions occurred at times at the frequencies of surface waves. {\textbullet} The rate of change of O2 concentration was negatively correlated with fluxes. {\textbullet} The benthic O2 flux was primarily into the bed (-18{\textpm}3 mmol m-2 d-1). {\textbullet} Inner shelf benthic O2 fluxes were 2{\textendash}5 times greater than fluxes on the mid-shelf. Abstract Measurement of in situ O2 consumption and production within permeable sediments, such as those found over the Oregon{\textendash}Washington inner shelf, has traditionally been done using methods that isolate the sediments from the dynamic influences of currents and wave motions. Modified from atmospheric research, the non-invasive eddy correlation technique can be used to characterize benthic boundary layer dynamics and measure O2 flux across the sediment{\textendash}water interface without excluding the natural hydrodynamic flow. In 2009, eddy correlation measurements were made in 5 discrete months with varying conditions at a 30 m site off Yaquina Head, Newport, OR. The O2 flux was found to be primarily into the bed (-18{\textpm}3 mmol m-2 d-1; mean{\textpm}SE, n=137 15-min bursts) but was sensitive to non-steady state changes in O2 concentrations caused by the differential advection of water masses with variable mean O2 concentrations. Important contributions to O2 eddy fluxes at surface wave frequencies were seen in eddy correlation cospectra and these are interpreted as being indicative of consumption enhanced by advective transport of O2 into the bed. The sediments were deposits of fine sand with permeabilities of 1.3{\textendash}4.7{\texttimes}10-11 m2 and wave-generated ripples. Sediment pigment and organic carbon concentrations were low (chlorophyll-α: 0.02{\textendash}0.45 μg g-1, phaeophytin-α: 0.38{\textendash}1.38 μg g-1 and organic carbon: 0.05{\textendash}0.39\% dry wt in discrete depth intervals from cores collected between March and October), but it was evident that during the summer fresh pigments were trapped in the sand and rapidly mixed over the uppermost 0{\textendash}13 cm. From these results it is inferred that physical forcing associated largely with waves and currents may accentuate the role of sediment-covered inner shelf habitats as a regional O2 sink compared to the middle shelf. In effect, the action of waves and currents in the benthic boundary layer enables aerobic respiration that counterbalances the oxygenation of the water column by primary production and mixing in the surface layer.}, keywords = {Benthic boundary layer, Eddy correlation, Hypoxia, Oregon shelf, Oxygen consumption, Permeable sediments}, issn = {0278-4343}, doi = {10.1016/j.csr.2014.05.010}, url = {://WOS:000339696200009}, author = {McCann-Grosvenor, K. and Reimers, C. E. and Sanders, R. D.} } @article {RN229, title = {Establishing a new era of submarine volcanic observatories: Cabling Axial Seamount and the Endeavour Segment of the Juan de Fuca Ridge}, journal = {Marine Geology}, volume = {352}, year = {2014}, pages = {426-450}, type = {Journal Article}, abstract = {At least 70\% of the volcanism on Earth occurs along the 65,000 km network of mid-ocean ridge (MOR) spreading centers. Within these dynamic environments, the highest fluxes of heat, chemicals, and biological material from the lithosphere to the hydrosphere occur during volcanic eruptions. However, because underwater volcanoes are difficult and expensive to access, researchers are rarely, if ever, in the right place at the right time to characterize these events. Therefore, our knowledge is limited about the linkages among hydrothermal, chemical and biological processes during seafloor formation and crustal evolution. To make significant advancements in understanding the evolution of MOR environments, the United States and Canada have invested in the first plate-scale submarine cabled observatory linked through the global Internet. Spanning the Juan de Fuca tectonic plate, these two networks include > 1700 km of cable and 14 subsea terminals that provide 8{\textendash}10 kW power and 10 Gbs communications to hundreds of instruments on the seafloor and throughout the overlying water column {\textemdash} resulting in a 24/7/365 presence in the oceans. Data and imagery are available in real- to near-real time. The initial experimental sites for monitoring volcanic processes include the MOR volcanoes called Axial Seamount and the Endeavour Segment that are located on the Juan de Fuca Ridge. Axial, a hot-spot influenced seamount, is the most robust volcano along the ridge rising nearly 1400 m above the surrounding seafloor and it has erupted twice in the last 15 years. In contrast, the Endeavour Segment is characterized by more subdued topography with a well defined axial rift and it hosts one of the most intensely venting hydrothermal systems known. A non-eruptive spreading event lasting 6 years was documented at Endeavour between 1999 and 2005. Hydrothermal venting intensity, chemistry, and temperature, as well as associated biological communities at both sites were significantly perturbed by the magmatic and intrusive events. This paper presents the similarities and differences between the Axial and Endeavour volcanic systems and identifies reasons why they are ideal candidates for comparative studies. The U.S. has made a 25-year commitment for sustained observations using the cabled infrastructure. The highly expandable nature of submarine optical networking will allow for the future addition of novel experiments that utilize ever evolving advancements in computer sciences, robotics, genomics and sensor miniaturization. Comprehensive modeling of the myriad processes involved will continue to assimilate and integrate growing databases yielding a new understanding of integrated processes that create the seafloor in the global ocean basins. }, keywords = {axial seamount, cabled observatories, Endeavour Segment, hydrothermal vents, Juan de Fuca ridge, submarine volcanoes}, issn = {0025-3227}, doi = {https://doi.org/10.1016/j.margeo.2014.03.010}, url = {https://www.sciencedirect.com/science/article/pii/S0025322714000723}, author = {Kelley, Deborah S. and Delaney, John R. and Juniper, S. Kim} } @article {RN55, title = {Globally Governed Session Semantics}, journal = {Logical Methods in Computer Science}, volume = {10}, number = {4}, year = {2014}, type = {Journal Article}, abstract = {This paper proposes a bisimulation theory based on multiparty session types where a choreography specification governs the behaviour of session typed processes and their observer. The bisimulation is defined with the observer cooperating with the observed process in order to form complete global session scenarios and usable for proving correctness of optimisations for globally coordinating threads and processes. The induced bisimulation is strictly more fine-grained than the standard session bisimulation. The difference between the governed and standard bisimulations only appears when more than two interleaved multiparty sessions exist. This distinct feature enables to reason real scenarios in the large-scale distributed system where multiple choreographic sessions need to be interleaved. The compositionality of the governed bisimilarity is proved through the soundness and completeness with respect to the governed reduction-based congruence. Finally, its usage is demonstrated by a thread transformation governed under multiple sessions in a real usecase in the large-scale cyberinfrustracture.}, issn = {1860-5974}, doi = {10.2168/Lmcs-10(4:20)2014}, url = {://WOS:000350399900021}, author = {Kouzapas, D. and Yoshida, N.} } @article {RN232, title = {Is biological productivity enhanced at the New England shelfbreak front?}, journal = {Journal of Geophysical Research-Oceans}, volume = {118}, number = {1}, year = {2013}, pages = {517-535}, type = {Journal Article}, abstract = {[1] A two-dimensional (cross-shelf) numerical model of the mean seasonal circulation offshore of southern New England predicts upwelling at the shelfbreak front. Expected ramifications of this upwelling include enhancement of nutrient supply, phytoplankton biomass, and productivity. However, seasonal climatologies of chlorophyll based on both in situ data and satellite observations show no mean enhancement at the front. We investigate this apparent discrepancy with a four-component planktonic ecosystem model coupled to the two-dimensional physical model. Nutrient fields are restored to climatological values at depth, and upper ocean values evolve freely according to physical and biological forcing. Vertical diffusivity is based on seasonally averaged surface and bottom mixed layer depths compiled from in situ observations. The model reproduces the general pattern of the observed cross-shelf and seasonal variations of the chlorophyll distribution. It predicts a local enhancement of phytoplankton productivity at the shelfbreak in spring and summer as a result of the persistently upwelled nutrient-rich slope water. In the model, zooplankton grazing prevents accumulation of phytoplankton biomass at the site of the upwelling. The predicted enhancement of primary productivity (but not phytoplankton biomass) at the shelfbreak constitutes a hypothesis that could be tested in the future with suitable measurements from regional long-term observatories, such as the Ocean Observatories Initiative Pioneer Array.}, issn = {2169-9275}, doi = {10.1002/jgrc.20068}, author = {Zhang, W. F. G. and McGillicuddy, D. J. and Gawarkiewicz, G. G.} } @article {RN20, title = {Horizontal Scales of Variability over the Middle Atlantic Bight Shelf Break and Continental Rise from Finescale Observations}, journal = {Journal of Physical Oceanography}, volume = {43}, number = {1}, year = {2013}, pages = {222-230}, type = {Journal Article}, abstract = {Observations with fine horizontal resolution are used to identify the horizontal scales of variability over the Middle Atlantic Bight (MAB) shelf break and continental rise. Spray gliders collected observations along two alongshelf transects over the continental rise in March{\textendash}April 2006 and along 16 cross-shelf transects over the shelf break and continental rise during July{\textendash}October 2007. Horizontal resolution varied from 1 km or finer over the shelf to 6 km in deep water. These observations allow horizontal thermohaline variability offshore of the MAB shelf break to be examined for the first time. Structure functions of temperature and salinity, the mean square difference between observations separated by specified distances, reveal the horizontal spatial scales in the region. Exponential (e-folding) scales of temperature and salinity increase from 8{\textendash}13 km near the shelf break to about 30 km over the continental rise. Just offshore of the shelf break, alongshelf structure functions exhibit periodicity with a 40{\textendash}50-km wavelength that matches the wavelength of shelfbreak frontal meanders. Farther offshore, alongshelf structure functions suggest a dominant wavelength of 175{\textendash}250 km, but these scales are only marginally resolved by the available observations. Examination of structure functions of along-isopycnal salinity (i.e., spice) suggests that interleaving of shelf and slope water masses contributes most of the horizontal variability near the MAB shelf break, but heaving of isopycnals is the primary source of horizontal variability over the continental rise.}, keywords = {Continental shelf/slope, Fronts, In situ oceanic observations, North Atlantic Ocean, oceanic, Profilers}, issn = {0022-3670 1520-0485}, doi = {10.1175/jpo-d-12-099.1}, url = {https://doi.org/10.1175/JPO-D-12-099.1}, author = {Todd, Robert E. and Gawarkiewicz, Glen G. and Owens, W. Brechner} } @article {RN56, title = {Multi-model ensemble forecasting and glider path planning in the Mid-Atlantic Bight}, journal = {Continental Shelf Research}, volume = {63}, year = {2013}, pages = {S223-S234}, type = {Journal Article}, abstract = {During the first two weeks of November 2009, a field experiment was conducted in the Mid-Atlantic Bight region to demonstrate a coastal ocean observatory that can collect observations from heterogeneous platforms and forecast fields from four different ocean models, provide multi-model ensemble forecasts based on either an equal weighting (EQ) or objective weighting (OBJ) method, and use model forecasts in a path planning system to relocate autonomous gliders. This experiment is a prototype for the command and control component of cyberinfrastructure of the Ocean Observatories Initiative funded by the National Science Foundation. The four individual models use different forcing fields, boundary conditions and data assimilation techniques, and have resolutions varying from 2 km to 15 km. Our results indicate that for sea surface temperature and surface currents, the OBJ ensemble outperforms the four individual models, while the EQ ensemble can also provide an effective way to improve individual model forecasts. In terms of glider path planning, the OBJ ensemble has a performance similar to the best individual model, which has the finest horizontal resolution. This field experiment demonstrates the first-ever use of ensemble current forecasts to guide glider path planning in the context of real-time data collection and ocean model forecasting. }, keywords = {Ensemble forecasting Objective weighting method, Equal weighting method, Glider path planning, Mid-Atlantic Bight}, issn = {0278-4343}, doi = {10.1016/j.csr.2012.07.006}, url = {://WOS:000323188800018}, author = {Wang, X. C. and Chao, Y. and Thompson, D. R. and Chien, S. A. and Farrara, J. and Li, P. and Vu, Q. and Zhang, H. C. and Levin, J. C. and Gangopadhyay, A.} } @article {RN230, title = {Sulfur oxidizers dominate carbon fixation at a biogeochemical hot spot in the dark ocean}, journal = {The ISME Journal}, volume = {7}, number = {12}, year = {2013}, pages = {2349-2360}, type = {Journal Article}, abstract = {Bacteria and archaea in the dark ocean (>200 m) comprise 0.3-1.3 billion tons of actively cycled marine carbon. Many of these microorganisms have the genetic potential to fix inorganic carbon (autotrophs) or assimilate single-carbon compounds (methylotrophs). We identified the functions of autotrophic and methylotrophic microorganisms in a vent plume at Axial Seamount, where hydrothermal activity provides a biogeochemical hot spot for carbon fixation in the dark ocean. Free-living members of the SUP05/Arctic96BD-19 clade of marine gamma-proteobacterial sulfur oxidizers (GSOs) are distributed throughout the northeastern Pacific Ocean and dominated hydrothermal plume waters at Axial Seamount. Marine GSOs expressed proteins for sulfur oxidation (adenosine phosphosulfate reductase, sox (sulfur oxidizing system), dissimilatory sulfite reductase and ATP sulfurylase), carbon fixation (ribulose-1,5-bisphosphate carboxylase oxygenase (RuBisCO)), aerobic respiration (cytochrome c oxidase) and nitrogen regulation (PII). Methylotrophs and iron oxidizers were also active in plume waters and expressed key proteins for methane oxidation and inorganic carbon fixation (particulate methane monooxygenase/methanol dehydrogenase and RuBisCO, respectively). Proteomic data suggest that free-living sulfur oxidizers and methylotrophs are among the dominant primary producers in vent plume waters in the northeastern Pacific Ocean. }, issn = {1751-7370}, doi = {10.1038/ismej.2013.113}, url = {https://doi.org/10.1038/ismej.2013.113}, author = {Mattes, Timothy E. and Nunn, Brook L. and Marshall, Katharine T. and Proskurowski, Giora and Kelley, Deborah S. and Kawka, Orest E. and Goodlett, David R. and Hansell, Dennis A. and Morris, Robert M.} } @article {RN234, title = {Design and Application of a Junction Box for Cabled Ocean Observatories}, journal = {Marine Technology Society Journal}, volume = {46}, number = {3}, year = {2012}, pages = {50-63}, type = {Journal Article}, abstract = {Cabled ocean observatories enabling large amounts of power and two-way communication bandwidth for underwater experiments are a future approach for studying the oceans. On April 21, 2011, at Monterey Bay, California, USA, a network node composed of a junction box (JBox) and three scientific instruments was deployed at the Monterey Accelerated Research System (MARS) site for a 6-month uninterrupted sea trial. The JBox is a facility that can provide multiple wet-mateable connections for various instruments. Each connection can draw 500 W of power and has 10/100 Mbit/s network communication. The current study presents the design and construction of the JBox with focus on the following aspects: a power distribution system with high reliability; a flexible springloaded mechanical structure for heat dissipation; communication that incorporates various data protocols; and self-protection against faults like over-current, short fault, ground fault, and flooding. The deployment and operation of the JBox is described. The sea trial results show that the technologies and methods applied on the JBox and the deploying approach are applicable and worthy of consideration for long-term cabled ocean observatories.}, issn = {0025-3324}, doi = {10.4031/MTSJ.46.3.4}, author = {Chen, Y. H. and Yang, C. J. and Li, D. J. and Jin, B. and Chen, Y.} } @article {RN233, title = {Direct interaction between the Gulf Stream and the shelfbreak south of New England}, journal = {Scientific Reports}, volume = {2}, year = {2012}, type = {Journal Article}, abstract = {Sea surface temperature imagery, satellite altimetry, and a surface drifter track reveal an unusual tilt in the Gulf Stream path that brought the Gulf Stream to 39.9{\textdegree}N near the Middle Atlantic Bight shelfbreak--200 km north of its mean position--in October 2011, while a large meander brought Gulf Stream water within 12 km of the shelfbreak in December 2011. Near-bottom temperature measurements from lobster traps on the outer continental shelf south of New England show distinct warming events (temperature increases exceeding 6{\textdegree}C) in November and December 2011. Moored profiler measurements over the continental slope show high salinities and temperatures, suggesting that the warm water on the continental shelf originated in the Gulf Stream. The combination of unusual water properties over the shelf and slope in late fall and the subsequent mild winter may affect seasonal stratification and habitat selection for marine life over the continental shelf in 2012. }, issn = {2045-2322}, doi = {10.1038/srep00553}, author = {Gawarkiewicz, G. G. and Todd, R. E. and Plueddemann, A. J. and Andres, M. and Manning, J. P.} } @article {RN58, title = {Parameterised Multiparty Session Types}, journal = {Logical Methods in Computer Science}, volume = {8}, number = {4}, year = {2012}, type = {Journal Article}, abstract = {For many application-level distributed protocols and parallel algorithms, the set of participants, the number of messages or the interaction structure are only known at run-time. This paper proposes a dependent type theory for multiparty sessions which can statically guarantee type-safe, deadlock-free multiparty interactions among processes whose specifications are parameterised by indices. We use the primitive recursion operator from G{\"o}del{\textquoteright}s System T to express a wide range of communication patterns while keeping type checking decidable. To type individual distributed processes, a parameterised global type is projected onto a generic generator which represents a class of all possible end-point types. We prove the termination of the type-checking algorithm in the full system with both multiparty session types and recursive types. We illustrate our type theory through non-trivial programming and verification examples taken from parallel algorithms and Web services usecases. }, keywords = {Computer Science, D.1.3, F.1.1, F.1.2, F.3.3, Logic in Computer Science}, issn = {1860-5974}, doi = {10.2168/Lmcs-8(4:6)2012}, url = {://WOS:000315381600008}, author = {Denielou, P. M. and Yoshida, N. and Bejleri, A. and Hu, R.} } @article {RN235, title = {The era of continental-scale ecology}, journal = {Frontiers in Ecology and the Environment}, volume = {9}, number = {6}, year = {2011}, pages = {311-311}, type = {Journal Article}, abstract = {Extending insights from ecology to the development of science-based principles in order to promote the stew-ardship of a human-dominated planet must engage the best minds of a generation. To effectively informsuch planetary decision-making, practitioners of ecology will have to address environmental interactions atincreasingly large scales. For example, managing biological invasions requires that scientists address issues ofspecies interactions and resource use in the face of unprecedented transport capabilities that can move organismsacross huge distances. Likewise, managing the global carbon cycle, and therefore the climate system, requiresobserving and forecasting biogeochemical processes consistently {\textendash} from the scale of individual management pro-jects to that of the entire world. Such challenges will require that ecologists apply the discipline{\textquoteright}s knowledge ofthe living world not just at well-studied local sites but across regions, continents, and ultimately the planet.}, issn = {1540-9295}, doi = {10.1890/1540-9295-9.6.311}, author = {Schimel, D.} } @article {RN60, title = {The Ocean Observatories Initiative: Sustained Ocean Observing Across a Range of Spatial Scales}, journal = {Marine Technology Society Journal}, volume = {44}, number = {6}, year = {2010}, pages = {54-64}, type = {Journal Article}, abstract = {The Ocean Observatory Initiative of the U.S. National Science Foundation is working to advance the ocean sciences by developing the infrastructure for sustained ocean observations at key coastal and open ocean locations. The effort comprises two coastal arrays, four global arrays in the deep ocean, a cabled observatory over the Juan de Fuca tectonic plate, and a sophisticated cyberinfrastructure. The initial installations will be completed by 2015, and 25 years of operation will follow. This article provides an overview of the Ocean Observatory Initiative, followed by more detail about the coastal, regional, and global components. Science drivers are reviewed first. Then, the platforms to be deployed at each site, both moorings and mobile platforms, are described, as are the planned, multidisciplinary core sensors. All data will be freely available.}, issn = {0025-3324}, doi = {10.4031/Mtsj.44.6.21}, url = {://WOS:000286649500012}, author = {Cowles, T. and Delaney, J. and Orcutt, J. and Weller, R.} } @article {RN236, title = {Everything, everywhere}, journal = {Nature}, volume = {440}, number = {7083}, year = {2006}, pages = {402-405}, type = {Journal Article}, abstract = {Tiny computers that constantly monitor ecosystems, buildings and even human bodies could turn science on its head. Declan Butler investigates.}, issn = {0028-0836}, doi = {10.1038/440402a}, author = {Butler, D.} } @article {RN237, title = {Oceanography: All wired up}, journal = {Nature}, volume = {427}, number = {6969}, year = {2004}, pages = {10-12}, type = {Journal Article}, abstract = {The ocean floor is being covered with remote-controlled observatories, letting oceanographers keep tabs on the sea without getting wet. Jon Copley investigates.}, issn = {0028-0836}, doi = {10.1038/427010a}, author = {Copley, J.} } @article {RN62, title = {The Ocean Observatories Initiative: A continued presence for interactive ocean research}, journal = {Marine Technology Society Journal}, volume = {37}, number = {3}, year = {2003}, pages = {26-41}, type = {Journal Article}, abstract = {Global processes that actively shape the Earth and ultimately impact society must be investigated over the spatial and temporal scales at which they occur. To characterize the temporal behavior of dynamic processes occurring in the ocean, new types of infrastructure are needed that are capable of providing long-term, high-resolution observations of critical environmental parameters. With funding from the Major Research Equipment and Facilities Construction (MREFC) account, the National Science Foundation{\textquoteright}s Division of Ocean Sciences plans to initiate construction of an integrated observatory network that will provide the oceanographic research and education communities with a new mode of access to the ocean. The Ocean Observatories Initiative (OOI) has three elements: 1) a regional cabled network consisting of interconnected sites on the seafloor spanning several geological and oceanographic features and processes, 2) several relocatable deep-sea buoys that could also be deployed in harsh environments such as the Southern Ocean, and 3) new construction or enhancements to existing facilities leading to an expanded network of coastal observatories. The scientific problems driving the need for the OOI are broad in scope and encompass nearly every area of ocean science. Once established, the observatories constructed as part of this initiative will provide earth and ocean scientists with unique opportunities to study multiple, interrelated processes over time scales ranging from seconds to decades; to conduct comparative studies of regional processes and spatial characteristics; and to map whole-Earth and basin scale structures.}, issn = {0025-3324}, doi = {10.4031/002533203787537285}, url = {://WOS:000187402800008}, author = {Isern, A. R. and Clark, H. L.} }