Study of the formation of the Black Sea haline stratification from the numerical simulations

Abstract The excess of river runoff and precipitation over evaporation (positive freshwater balance) and the supply of the Marmara Sea highly saline waters through the Bosphorus is the cause of the sharp halocline in the 100-300 m layer and low vertical mixing in the permanent pycnocline layer, where the contribution salinity to the seawater density prevails compared to temperature. Such features of the Black Sea waters make the description of the process of formation of the haline stratification an actual and inexhausted problem. Investigating the patterns of the formation of the haline stratification in the Black Sea, a laboratory model of a rotating cylindrical cavity and a numerical model are proposed. Laboratory studies have shown that in a simple configuration, the buoyancy flux across the basin boundaries leads to the formation of a sharp pycnocline and the formation of a three-layer vertical structure of horizontal currents. Numerical experiments demonstrate that halocline is formed at a depth of 10-40 m. The haline stratification has been established with a pronounced halocline for about hundred years which later slowly evolved.