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| Bonhommeau, Sylvain; Blanke, Bruno; Treguier, Anne-marie; Grima, Nicolas; Rivot, Etienne; Vermard, Youen; Greiner, Eric; Le Pape, Olivier. |
| The migration duration of European eel (Anguilla anguilla) larvae (leptocephali) from the spawning areas in the Sargasso Sea to the European continental shelf remains highly controversial, with estimates varying from 6 months to more than 2 yr. We estimated the fastest migration period and the shortest distance travelled by eel larvae by simulating Lagrangian particles released in the Sargasso Sea and by simulating a range of larval behaviours (fixed-depth drift, vertical diurnal migration and active-depth selection to maximize current velocity). This enabled us to compute (i) a passive drift speed, and (ii) a hypothetic swimming speed needed for European eel larvae to cross the Atlantic in 6 months (i.e., the migration duration estimated from otolith... |
| Tipo: Text |
Palavras-chave: Sargasso Sea; Migration duration; Leptocephali; Lagrangian modelling; Gulf Stream; Fractals; Anguilla. |
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-6865.pdf |
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| Klymak, Jody M.; Shearman, R. Kipp; Gula, Jonathan; Lee, Craig M.; D'Asaro, Eric A.; Thomas, Leif N.; Harcourt, Ramsey R.; Shcherbina, Andrey Y.; Sundermeyer, Miles A.; Molemaker, Jeroen; Mcwilliams, James C.. |
| The Gulf Stream is a major conduit of warm surface water from the tropics to the subpolar North Atlantic. Here we observe and simulate a submesoscale (<20km) mechanism by which the Gulf Stream exchanges water with subpolar water to the north. Along isopycnals, the front has a sharp compensated temperature-salinity contrast, with distinct mixed water between the two water masses 2 and 4km wide. This mixed water does not increase downstream despite substantial energy available for mixing. A series of streamers detrain this water at the crest of meanders. Subpolar water replaces the mixed water and resharpens the front. The water mass exchange accounts for a northward flux of salt of 0.5-2.5 psum(2)s(-1), (large-scale diffusivity O (100m(2)s(-1))). This is... |
| Tipo: Text |
Palavras-chave: Ocean mixing; Gulf Stream; Submesoscale mixing; Eddies. |
| Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00600/71201/69570.pdf |
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| Talandier, Claude; Deshayes, Julie; Treguier, Anne-marie; Capet, Xavier; Benshila, Rachid; Debreu, Laurent; Dussin, Raphael; Molines, J. -m.; Madec, Gerard. |
| Previous studies have shown that low horizontal resolution (of the order of 1°) ocean models, hence climate models, are not able to adequately represent boundary currents nor mesoscale processes which affect the dynamics and thermohaline circulation of the ocean. While the effect of mesoscale eddies can be parameterized in low resolution models, boundary currents require relatively high horizontal resolution. We clarify the impact of increasing the resolution on the North Atlantic circulation, with emphasis on the Atlantic Meridional Overturning Circulation (AMOC), by embedding a 1/8° nest covering the North Atlantic into a global 1/2° model. Increasing the resolution in the nest leads to regional improvements of the circulation and thermohaline... |
| Tipo: Text |
Palavras-chave: Deep Western Boundary Current; Atlantic Meridional Overturning Circulation; North Atlantic Current; Gulf Stream; Subpolar gyre. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00173/28472/26812.pdf |
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| Gula, Jonathan; Blacic, Tanya M.; Todd, Robert E.. |
| Seismic images and glider sections of the Gulf Stream front along the U.S. eastern seaboard capture deep, lens‐shaped submesoscale features. These features have radii of 5–20 km, thicknesses of 150–300 m, and are located at depths greater than 500 m. These are typical signatures of anticyclonic submesoscale coherent vortices. A submesoscale‐resolving realistic simulation, which reproduces submesoscale coherent vortices with the same characteristics, is used to analyze their generation mechanism. Submesoscale coherent vortices are primarily generated where the Gulf Stream meets the Charleston Bump, a deep topographic feature, due to the frictional effects and intense mixing in the wake of the topography. These submesoscale coherent vortices can transport... |
| Tipo: Text |
Palavras-chave: Submesoscale coherent vortices; Glider; Seismic observations; Gulf Stream; Topographic interactions; Charleston Bump. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00484/59597/62599.pdf |
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