@article {castillo_cieza_unusual_2024,
	title = {Unusual \textit{Hemiaulus bloom influences ocean productivity in Northeastern US Shelf waters},
	journal = {Biogeosciences},
	volume = {21},
	number = {5},
	year = {2024},
	note = {Publisher: Copernicus GmbH},
	month = {mar},
	pages = {1235{\textendash}1257},
	abstract = {Because of its temperate location, high dynamic range of environmental conditions, and extensive human activity, the long-term ecological research site in the coastal Northeastern US Shelf (NES) of the northwestern Atlantic Ocean offers an ideal opportunity to understand how productivity shifts in response to changes in planktonic community composition. Ocean production and trophic transfer rates, including net community production (NCP), net primary production (NPP), gross oxygen production (GOP), and microzooplankton grazing rates, are key metrics for understanding marine ecosystem dynamics and associated impacts on biogeochemical cycles. Although small phytoplankton usually dominate phytoplankton community composition and Chl a concentration in the NES waters during the summer, in August 2019, a bloom of the large diatom genus Hemiaulus, with N2-fixing symbionts, was observed in the mid-shelf region. NCP was 2.5 to 9 times higher when Hemiaulus dominated phytoplankton carbon compared to NCP throughout the same geographic area during the summers of 2020{\textendash}2022. The Hemiaulus bloom in summer 2019 also coincided with higher trophic transfer efficiency from phytoplankton to microzooplankton and higher GOP and NPP than in the summers 2020{\textendash}2022. This study suggests that the dominance of an atypical phytoplankton community that alters the typical size distribution of primary producers can significantly influence productivity and trophic transfer, highlighting the dynamic nature of the coastal ocean. Notably, summer 2018 NCP levels were also high, although the size distribution of Chl a was typical and an atypical phytoplankton community was not observed. A better understanding of the dynamics of the NES in terms of biological productivity is of primary importance, especially in the context of changing environmental conditions due to climate processes.},
	issn = {1726-4170},
	doi = {10.5194/bg-21-1235-2024},
	url = {https://bg.copernicus.org/articles/21/1235/2024/},
	author = {Castillo Cieza, S. Alejandra and Stanley, Rachel H. R. and Marrec, Pierre and Fontaine, Diana N. and Crockford, E. Taylor and McGillicuddy Jr., Dennis J. and Mehta, Arshia and Menden-Deuer, Susanne and Peacock, Emily E. and Rynearson, Tatiana A. and Sandwith, Zoe O. and Zhang, Weifeng and Sosik, Heidi M.}
}
@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.}
}
@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 {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 {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 {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 {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 {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.}
}
