Numerical analysis of barotropic currents on the black-sea shelf on the basis of the hydrodynamic model developed at the marine hydrophysical institute of the ukrainian national academy of sciences

Abstract

We describe a three-dimensional nonlinear model of the Black Sea adapted for the numerical analyses of barotropic currents on the shelf. The specific features of finite-difference equations appearing in the presence of liquid boundaries are discussed. The problem of simulation of currents formed under the influence of climatic winds on the northwest shelf of the Black Sea is solved as an example. We analyze the results of three experiments in which the Dirichlet, free-flow, and mixed-type boundary conditions are imposed for the equations of motion in the open parts of the lateral boundaries. It is shown that the application of the Dirichlet conditions may lead to the inadequate vertical transfer near liquid boundaries. For the free-flow boundary conditions, the fields of sea level and current velocities in the nearboundary regions are characterized by the presence of significant errors. At the same time, the mixedtype boundary conditions enable us to decrease the errors of computed fields and describe the process of vertical transfer more accurately.