Comparaison des données altimétriques Topex-Poséidon en Méditerranée avec un modèle de circulation générale

Abstract

Outputs of a primitive-equation numerical model of the Mediterranean forced by 6-h ECMWF winds are compared with Topex-Poseidon surface topography measurements in 1993. The comparisons show a fair qualitative agreement on the structure of the general surface circulation and on a number of large-scale features. The high-frequency wind forcing is thought to objectively contribute to the control of the model trajectory. There is good agreement on the variations of the surface transport of the Algerian Current and Mid-Mediterranean jet. As expected, the medium model resolution ( 1 0/4 ) does not allow for a satisfying representation of the smaller scales in the model. The limited resolution accounts for large errors on the response to wind forcing, on the spindown of seasonal gyres, and on the instabilities and meanders of coastal currents. Nevertheless, this study can serve as a reference for a future step involving higher resolution modelling and assimilation.