@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 {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}
}
@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.}
}
