The impact of various types of open boundary conditions in numerical simulation of the Black Sea coastal circulation

Abstract

An important problem is to obtain a short-term forecast in the Black Sea coastal zone with a high resolution. It is solved on the basis of numerical modeling of ocean circulation. Carrying out simulations that allow reproducing the meso- and submesoscale processes in a reasonable machine time requires a considerable computational power. One of the common ways to solve this problem is to create a regional configuration (a nested domain). This work is performed to study the influence of methods of specifying open boundary conditions. To conduct such a study, a regional configuration corresponding to the southern coast of Crimea with a resolution of 1.5 km is developed. Four short-term numerical experiments are carried out to investigate the influence of various types of open boundary conditions on the simulation results. The results of the simulations have shown that for a correct reproduction of the hydrophysical parameters, barotropic velocities at the open border should not be taken into account. At the open boundary, in the fields of temperature and salinity, there is no numerical noise when using a flow relaxation scheme. The sea level is reproduced correctly when using a Flather-type scheme.