@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 {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.}
}
