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Su, Zhan; Wang, Jinbo; Klein, Patrice; Thompson, Andrew F.; Menemenlis, Dimitris. |
Recent studies highlight that oceanic motions associated with horizontal scales smaller than 50 km, defined here as submesoscales, lead to anomalous vertical heat fluxes from colder to warmer waters. This unique transport property is not captured in climate models that have insufficient resolution to simulate these submesoscale dynamics. Here, we use an ocean model with an unprecedented resolution that, for the first time, globally resolves submesoscale heat transport. Upper-ocean submesoscale turbulence produces a systematicallyupward heat transport that is five times larger than mesoscale heat transport, with wintertime averages up to 100 W/m2 for mid-latitudes. Compared to a lower-resolution model, submesoscale heat transport warms the sea surface up to... |
Tipo: Text |
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Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00449/56019/57535.pdf |
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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... |
Tipo: Text |
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Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00594/70562/71323.pdf |
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Siegelman, Lia; Klein, Patrice; Thompson, Andrew F.; Torres, Hector S.; Menemenlis, Dimitris. |
Recent studies demonstrate that energetic sub-mesoscale fronts (10–50 km width) extend in the ocean interior, driving large vertical velocities and associated fluxes. However, diagnosing the dynamics of these deep-reaching fronts from in situ observations remains challenging because of the lack of information on the 3-D structure of the horizontal velocity. Here, a realistic numerical simulation in the Antarctic Circumpolar Current (ACC) is used to study the dynamics of submesocale fronts in relation to velocity gradients, responsible for the formation of these fronts. Results highlight that the stirring properties of the flow at depth, which are related to the velocity gradients, can be inferred from finite-size Lyapunov exponent (FSLE) at the surface.... |
Tipo: Text |
Palavras-chave: Altimetry; Finite-size Lyapunov exponent; Ocean dynamics; Sub-mesoscale. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00645/75666/76532.pdf |
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Flexas, M. Mar; Thompson, Andrew F.; Torres, Hector S.; Klein, Patrice; Farrar, J. Thomas; Zhang, Hong; Menemenlis, Dimitris. |
Estimates of the kinetic energy transfer from the wind to the ocean are often limited by the spatial and temporal resolution of surface currents and surface winds. Here, we examine the wind work in a pair of global, very high‐resolution (1/48° and 1/24° ), MITgcm simulations in Latitude‐Longitude‐Cap configuration (LLC) that provide hourly output at spatial resolutions of a few kilometers and include tidal forcing. A cospectrum analysis of wind stress and ocean surface currents shows positive contribution at large scales (>300 km) and near‐inertial frequency, and negative contribution from mesoscales, tidal frequencies and internal gravity waves (IGWs). Larger surface kinetic energy fluxes are in the Kuroshio in winter at large scales (40 mW m−2) and... |
Tipo: Text |
Palavras-chave: Surface fluxes; Inertial oscillations; Wind power; Kinetic energy budget; Global ocean model; MITgcm. |
Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00509/62058/66232.pdf |
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