Numerical Simulation of the Seasonal Variability of Hydrophysical Fields in the Black Sea

Abstract

We present a brief description of a nonlinear numerical model used to reproduce the variability of large-scale circulation in the Black Sea under the action of seasonal boundary conditions. The calculated circulation is of cyclonic nature. The Main Black Sea Rim Current is presented for the whole year and flows along the continental slope. In the upper layers, seasonal variability manifests itself in the intensification of the Rim Current in winter, especially in the eastern part of the sea. In the annual average, we observe elevation in the central part of the sea and lowering on its periphery. In winter, we see strong elevation in the eastern part of the sea and lowering in its western part. In spring, we observe the opposite situation. In summer, the structure of vertical motions changes again and corresponds to the winter type. In autumn, it again becomes similar to that recorded in spring. The formation of a cold intermediate layer occurs as a result of the action of two mechanisms. In the central part of the basin, it is caused by the winter convection and, on the periphery of the main cyclonic circulation, by the formation of cold waters in the northwestern part of the sea, their subsequent lowering along the continental slope, and transportation by currents along the coast.