A SEASONAL MODEL OF THE MEDITERRANEAN-SEA GENERAL-CIRCULATION

This paper describes the seasonal characteristics of the Mediterranean Sea general circulation as simulated by a primitive equation general circulation model. The forcing is composed of climatological monthly m ean atmospheric parameters, which are used to compute the heat and mom entum budgets at the air-sea interface of the model. This allows heat fluxes to be determined by a realistic air-sea interaction physics. Th e Strait of Gibraltar is open, and the model resolution is 1/4 degrees x 1/4 degrees in the horizontal and 19 Strait of Gibraltar is open, a nd the model resolution is, levels in the vertical, The results show t he large seasonal cycle of the circulation and its transient character istics. The heat budget at the surface is characterized by lateral bou ndary intensifications occurring in downwelling and upwelling areas of the basin. The general circulation is composed of subbasin gyres, and cyclonic motion dominates the northern and anticyclonic motion the so uthern part of the basin, The Atlantic stream which enters from Gibral tar and assumes the form of different boundary current subsystems is a coherent structure at the surface. At depth it appears as current seg ments and jets around a vigorous gyre system. The seasonal variability is manifested not only by a change in amplitude and location of the g yres but also by the appearance of seasonally recurrent gyres in diffe rent parts of the basin. Distinct westward propagation of these gyres occurs, together with amplitude changes. For the first time a Mersa-Ma truh Gyre is successfully simulated due to the introduction of our hea t fluxes at the air-sea interface, The seasonal thermocline is formed each summer, and a deep winter mixed layer is produced in the region o f Levantine intermediate water formation, Deep water renewal does not occur, probably due to the climatological forcing used.