Modeling the seasonal variability of the black sea hydrophysical fields with harmonic and biharmonic parametrizations of the horizontal friction force

摘要

On the basis of a numerical model for Black Sea dynamics with seasonal boundary conditions, two prognostic experiments were conducted for a period of ten years. The calculations were characterized by two parametrization schemes for the horizontal friction force in the equations of motion. The first scheme included the Laplace operator, and the second was based on the biharmonic approximation. In the second case, vertical motios are shown to be more intense, which leads to qualitative and quantitative changes in the hydrophysical fields. The differences across the Black Sea Rim Current (BSRC) are found to be larger in the second experiment. In deep layers, the salinity-temperature field includes a continuous boundary layer along the entire lateral boundary of the basin, which is not characteristic of the first experiments. The results obtained allows us to infer that the biharmonic friction approximation is favored for the reproduction of large-scale currents.