Diagnosing Surface Mixed Layer Dynamics from High-Resolution Satellite Observations: Numerical Insights
|Copyright||2013 American Meteorological Society|
|Author(s)||Ponte Aurelien1, Klein Patrice1, Capet Xavier2, Le Traon Pierre-Yves3, Chapron Bertrand3, Lherminier Pascale1|
|Affiliation(s)||1 : IFREMER, CNRS, UBO, Lab Phys Oceans,IRD, F-29280 Plouzane, France.
2 : IPSL, LOCEAN, Paris, France.
3 : IFREMER, Lab Oceanog Spatiale, F-29280 Plouzane, France.
|Source||Journal Of Physical Oceanography (0022-3670) (Amer Meteorological Soc), 2013-07 , Vol. 43 , N. 7 , P. 1345-1355|
|WOS© Times Cited||13|
|Keyword(s)||Mesoscale processes, Ocean dynamics, Turbulence|
|Abstract||High-resolution numerical experiments of ocean mesoscale eddy turbulence show that the wind-driven mixed layer (ML) dynamics affects mesoscale motions in the surface layers at scales lower than O(60 km). At these scales, surface horizontal currents are still coherent to, but weaker than, those derived from sea surface height using geostrophy. Vertical motions, on the other hand, are stronger than those diagnosed using the adiabatic quasigeotrophic (QG) framework. An analytical model, based on a scaling analysis and on simple dynamical arguments, provides a physical understanding and leads to a parameterization of these features in terms of vertical mixing. These results are valid when the wind-driven velocity scale is much smaller than that associated with eddies and the Ekman number (related to the ratio between the Ekman and ML depth) is not small. This suggests that, in these specific situations, three-dimensional ML motions (including the vertical velocity) can be diagnosed from high-resolution satellite observations combined with a climatological knowledge of ML conditions and interior stratification.|