Objectif Parameterizations of vertical mixing in existing Black Sea models are based on the use of a vertical eddy viscosity coefficient, an approach not efficient enough to describe mixing processes in strongly stratified seas. Data obtained in the Black Sea during the past decade shows that better parameterizations of convection and upper layer mixing are needed to model realistically the large-scale circulation, the interaction between the surface layer and deep layers, and the dispersion of tracers in the open sea. A characteristic feature of the Black Sea stratification is the sharp halocline separating a low salinity upper layer from higher salinity below 150 m, with a temperature minimum, refered to as the Cold Intermediate Layer (CIL) between the halocline & the seasonal thermocline The relevant physical mechanisms are described as follows. The CIL is generated bY convection occurring during winter in regions where relatively warm saline waters are upwelled to the surfaces, in the centres of large-scale cyclonic circulations in the open sea and over continental shele slopes. As the upwelling waters mix with the fresh and cold surface waters, density increases and triggers convective mixing. In addition, cold dense waters from the surface mixed layer creep down along isopycnal surfaces, forming the CIL above the halocline. Deepening of these waters result in a strengthening of eddy currents. Research work will be focused on studying and parameterizing the following processes : - Mixing of two water masses with different temperature and salinity ; - Isopycnic creeping. A linear model will be used, of the type described in Frankignoul and Muller (1979). The depth and rate of isopycnal creeping will be defined as functions of temperature, salinity and large-scale velocity. This research work will usefullv interact with the research work by Participant 8 (P. HAUGAN) Programme(s) IC-PECO/COPERNICUS - Scientific and technological cooperation between the European Community and European non-member countries, 1992- Thème(s) 01 - CEEC participation in ENVIRONMENT programme Appel à propositions Data not available Régime de financement CSC - Cost-sharing contracts Coordinateur CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE Contribution de l’UE Aucune donnée Adresse Ecole Polytechnique 91128 PALAISEAU France Voir sur la carte Coût total Aucune donnée Participants (1) Trier par ordre alphabétique Trier par contribution de l’UE Tout développer Tout réduire Institute of Oceanology - Bulgarian Academy of Sciences Bulgarie Contribution de l’UE Aucune donnée Adresse 9000 Varna Voir sur la carte Coût total Aucune donnée