Modeling studies of ocean-atmosphere coupling at the oceanic mesoscale
Résumé
Several recent studies, mainly based on satellite observations, have shown significant coupled interactions between the ocean and the atmosphere at oceanic mesoscales. There are unambiguous relations between sea surface temperature gradient and surface winds and clear imprints of oceanic eddies in the lower atmosphere. We use high resolution regional ocean-atmosphere coupled model configurations to study these interactions in eastern boundary upwelling systems (California and Peru-Chile). Different model solutions are analyzed to understand the combined effects of sea surface temperature and oceanic surface currents on the ocean-atmosphere interaction. A particular attention is given to the impact of the coupling processes on coherent anticyclonic and cyclonic mesoscale eddies. We show significant modification of the eddies characteristics (e.g. intensity, horizontal and vertical structures) and of the above atmospheric conditions (e.g. near-surface wind, boundary layer). Geographical and temporal variations of the mesoscale coupling intensity are also discussed. Perspectives are given by presenting preliminary results from an extended tropical channel coupled ocean-atmosphere model at high-resolution (1/12°).