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| Siegelman, Lia; Klein, Patrice; Rivière, Pascal; Thompson, Andrew F.; Torres, Hector S.; Flexas, Mar; Menemenlis, Dimitris. |
| The ocean is the largest solar energy collector on Earth. The amount of heat it can store is modulated by its complex circulation, which spans a broad range of spatial scales, from metres to thousands of kilometres. In the classical paradigm, fine oceanic scales, less than 20 km in size, are thought to drive a significant downward heat transport from the surface to the ocean interior, which increases oceanic heat uptake. Here we use a combination of satellite and in situ observations in the Antarctic Circumpolar Current to diagnose oceanic vertical heat transport. The results explicitly demonstrate how deep-reaching submesoscale fronts, with a size smaller than 20 km, are generated by mesoscale eddies of size 50–300 km. In contrast to the classical... |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00594/70562/71323.pdf |
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| Siegelman, Lia; O’toole, Malcolm; Flexas, Mar; Rivière, Pascal; Klein, Patrice. |
| The area west of the Kerguelen Islands (20–70°E/45–60°S) is characterized by a weak mesoscale activity except for a standing meander region of the Antarctic Circumpolar Current (ACC) localized between 20 and 40°E. A unique bio-physical dataset at high-resolution collected by a southern elephant seal (Mirounga leonina) reveals a conspicuous increase in foraging activity at the standing meander site up to 5 times larger than during the rest of her three-month trip west of the Kerguelen Islands. Here, we propose a physical explanation for such high biological activity based on the study of small-scale fronts with scales of 5 to 20 km, also called submesoscales. The standing meander is associated with intensified frontal dynamics at submesoscale, not observed... |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00489/60038/63305.pdf |
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| Rivière, Pascal; Jaud, Thomas; Siegelman, Lia; Klein, Patrice; Cotté, Cedric; Le Sommer, Julien; Dencausse, Guillaume; Guinet, Christophe. |
| Sub‐mesoscale fronts—with scales from 1 to 50 km are ubiquitous in satellite images of the world oceans. They are known to generate strong vertical velocities with significant impacts on biogeochemical fluxes and pelagic ecosystems. Here, we use a unique data set, combining high‐resolution behavioral and physical measurements, to determine the effects of sub‐mesoscale structures on the foraging behavior of 12 instrumented female southern elephant seals. These marine mammals make long voyages (several months over more than 2000 km), diving and feeding continuously in the Antarctic Circumpolar Current. Our results show that elephant seals change their foraging behavior when crossing sub‐mesoscale fronts: They forage more and at shallower depths inside... |
| Tipo: Text |
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| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00584/69636/67497.pdf |
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| Chenillat, Fanny; Blanke, Bruno; Grima, Nicolas; Franks, Peter J. S.; Capet, Xavier; Rivière, Pascal. |
| Eulerian models coupling physics and biology provide a powerful tool for the study of marine systems, complementing and synthesizing in situ observations and in vitro experiments. With the monotonic improvements in computing resources, models can now resolve increasingly complex biophysical interactions. Quantifying complex mechanisms of interaction produces massive amounts of numerical data that often require specialized tools for analysis. Here we present an Eulerian-Lagrangian approach to analyzing tracer dynamics in moving fluids. As an example of its utility, we apply this tool to quantifying plankton dynamics in oceanic mesoscale coherent structures. In contrast to Eulerian frameworks, Lagrangian approaches are particularly useful for revealing... |
| Tipo: Text |
Palavras-chave: Biophysicalinteractions; Planktondynamics; Ecosystemfunctioning; Lagrangiantrajectories; Ocean dynamics; Mesoscaleprocesses; Eddytracking; Coherentstructures. |
| Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00469/58028/60447.pdf |
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