scholarly journals Intrusions of Gulf Stream waters onto the South Atlantic Bight shelf

2011 ◽  
Vol 116 (C10) ◽  
Author(s):  
Renato Castelao
Keyword(s):  
Gulf Stream ◽  
South Atlantic ◽  
South Atlantic Bight ◽  
The South ◽  
Stream Waters

Cross-Shelf Exchange Associated With the Gulf Stream in the South Atlantic Bight: Direct Observations Using an Autonomous Underwater Glider

2018 ◽  
Vol 52 (3) ◽  
pp. 19-27 ◽  
Author(s):  
Ruoying He ◽  
Austin C. Todd ◽  
Chad Lembke ◽  
Todd Kellison ◽  
Chris Taylor ◽  
...  
Keyword(s):  
Gulf Stream ◽  
Moving Boundary ◽  
South Atlantic ◽  
South Atlantic Bight ◽  
Underwater Glider ◽  
The South ◽  
Underwater Gliders ◽  
Direct Observations ◽  
Autonomous Underwater Glider

AbstractAn autonomous underwater glider was deployed in March 2014 to sample the Gulf Stream and its adjacent shelf waters in the South Atlantic Bight, providing a new look at cross-shelf exchange associated with Gulf Stream dynamics. Observations collected over 4 weeks reveal significant cross-shelf exchange (up to 0.5 Sv) at the shoreward edge of the Gulf Stream, which was 2 orders of magnitude larger than estimates from long-term mean hydrographic conditions. Gulf Stream frontal eddies may have contributed to some of the largest fluxes of heat (0.5°C Sv) and salt (0.03 Sv g/kg) onto the shelf. We estimate that the largest upwelling event during the mission could have brought nitrate concentrations over 20 μM to within 125 m of the surface. This study demonstrates clear capabilities of autonomous underwater gliders for sampling in and near fast moving boundary currents to obtain unique and critical in situ observations effectively.

scholarly journals Submesoscale Dynamics of a Gulf Stream Frontal Eddy in the South Atlantic Bight

2016 ◽  
Vol 46 (1) ◽  
pp. 305-325 ◽  
Author(s):  
Jonathan Gula ◽  
M. Jeroen Molemaker ◽  
James C. McWilliams
Keyword(s):  
Gulf Stream ◽  
South Atlantic ◽  
Velocity Shear ◽  
Small Scale ◽  
South Atlantic Bight ◽  
Barotropic Instability ◽  
The South ◽  
Sheared Flow ◽  
Centrifugal Instability ◽  
Sharp Fronts

AbstractFrontal eddies are commonly observed and understood as the product of an instability of the Gulf Stream along the southeastern U.S. seaboard. Here, the authors study the dynamics of a simulated Gulf Stream frontal eddy in the South Atlantic Bight, including its structure, propagation, and emergent submesoscale interior and neighboring substructure, at very high resolution (dx = 150 m). A rich submesoscale structure is revealed inside the frontal eddy. Meander-induced frontogenesis sharpens the gradients and forms very sharp fronts between the eddy and the adjacent Gulf Stream. The strong straining increases the velocity shear and suppresses the development of barotropic instability on the upstream face of the meander trough. Barotropic instability of the sheared flow develops from small-amplitude perturbations when the straining weakens at the trough. Small-scale meandering perturbations evolve into rolled-up submesoscale vortices that are advected back into the interior of the frontal eddy. The deep fronts mix the tracer properties and enhance vertical exchanges of tracers between the mixed layer and the interior, as diagnosed by virtual Lagrangian particles. The frontal eddy also locally creates a strong southward flow against the shelf leading to topographic generation of submesoscale centrifugal instability and mixing. In eddy-resolving models that do not resolve these submesoscale processes, there is a significant weakening of the intensity of the upwelling in the core of the frontal eddies, and their decay is generally too fast.

Island in the Stream: Oceanography and Fisheries of the Charleston Bump

2001 ◽  
Keyword(s):  
Continental Shelf ◽  
Gulf Stream ◽  
Early Life ◽  
Bottom Topography ◽  
South Atlantic ◽  
South Atlantic Bight ◽  
The South ◽  
Pelagic Fishes ◽  
Charleston Bump ◽  
Pelagic Longline

<em>Abstract.</em>—The Charleston Bump is a complex bottom feature of great topographic relief located southeast of Charleston, South Carolina. This bottom feature deflects the Gulf Stream offshore in the South Atlantic Bight, and establishes permanent and temporary eddies, gyres, and associated upwellings in the warm Gulf Stream flow. Thermal fronts associated with Gulf Stream deflection, and die bottom feature itself, are believed to be attractive to large pelagic fishes, or result in concentrations of larvae, juveniles, and prey for larger fish. Upwelling in the region supports early life history stages of important fishery species. Deflection of the Gulf Stream may also play a direct or indirect role in transport of early life stages toward, or away from, nursery areas. Sea surface temperatures (SSTs) influenced by the Gulf Stream response to the Charleston Bump appear to have a role in determining recruitment success in gag <em> Mycteroperca microlepis, </em>a continental shelf reef fish. Relative cohort strength in gag was correlated (r = 0.89) to SST at 33°30'N, 78°30' W. Variability in conditions mat affect recruitment of larvae and juveniles, combined with heavy fishing pressure on prespawning adults, may result in recruitment failure in gag. In addition to strongly influencing circulation patterns in the South Atlantic Bight, die rugged bottom topography of the Bump is an important habitat and spawning ground for wreckfish <em> Polyprion americanus </em>and supports die U.S. fishery for this species. As a result, die Bump is an essential habitat for this species in U.S. waters. A geographic analysis of commercial pelagic longline logbook data shows mat die Charleston Bump is an area of concentrated commercial fishing effort, and that pelagic longline fisheries also concentrate along fronts at die edges of Gulf Stream gyres and eddies downstream. The "Charleston Bump Complex" of rough bottom topography and dynamic oceanography is an essential habitat for wreckfish and highly migratory pelagic fishes, and may influence recruitment success in some continental shelf fishes.

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