Computing Modeling of Hydrothermodynamics of the Southeastern Part of the Black Sea

The paper presents the modeling of regional hydrothermodynamic processes in the southeastern Black Sea using a high-resolution regional numerical model of the Black Sea dynamics based on a primitive system of ocean hydro and thermodynamics equations. The system of equations is solved by the method of two-cycle splitting into physical processes, coordinate planes, and lines, which allows us to reduce the solution of a 3-D nonstationary problem to solving relatively simple one and two-dimensional problems. The regional model with a spatial resolution of 1 km was nested in a basin-scale model with a resolution of 5 km. Numerical experiments conducted under real nonstationary atmospheric forcing show the permanent formation of mesoscale and unstable submesoscale eddies in the southeastern Black Sea with a size of approximately 215x340 km. Among the coastal eddies, the most intense formation is the Batumi anticyclonic eddy. The predicted sea surface temperature is compared with satellite data, and the simulated surface circulation with a resolution of 1 km is compared with the circulation obtained using a basin-scale model with a resolution of 5 km. These comparisons demonstrate the reliability of the regional model and the importance of high resolution for adequately reproducing mesoscale and submesoscale eddies in the coastal zone. The contribution of atmospheric wind forcing and other factors to the circulation processes is studied. As a result of the analysis of the numerical experiments, an important contribution of the atmospheric wind forcing to the formation of circulation in the upper 10-15-meter layer was revealed. Strong winds are a factor preventing the formation of eddy structures, including the Batumi eddy.