Assessment of Current Influence on the Wind Wave Parameters in the Black Sea based on Numerical Modeling

Abstract

Currents affect wind waves parameters. The issue of significance of this influence for the Black Sea has not been studied properly. The purpose of this paper is to study the scale, spatial and temporal variability of influence of sea currents on the wave height in the Black Sea. The research was carried out based on simulation using SWAN wave model and an irregular computational grid. Two datasets were used as input data: the NCEP/CFSv2 wind reanalysis and current data taken from the Remote Sensing Department's archive of the Marine Hydrophysical Institute of RAS. It is shown that the average wave height mainly decreases when sea current is considered. These changes are insignificant relative to the average values of wave heights. The greatest negative changes are typical of the western and northeast parts of the Black Sea. Here, the consideration of circulation reduces the average annual wave heights by up to 0.1 m. A slight increase in the average wave height is typical of the southern and southeast parts of the sea as well as the northwest shelf. The positive contribution to the mean annual wave heights is up to 0.02 m. When taken into account, currents change wave parameters at a maximum in winter months and at a minimum in late spring and summer. Currents change the mean monthly wave heights by –0.04…0.06 m in January and February in most parts of the sea. The contribution of currents is close to zero in June and July. The maximum changes in wave height reach 6–10 % of the monthly average.