Influence of the North Atlantic Oscillation and East Atlantic Pattern on Wind Stress Curl over the Black Sea

The influence of two climate modes (North Atlantic Oscillation (NAO) and East Atlantic pattern (EA)) on the wind stress curl (WSC) over the Black Sea, which determines the intensity of water circulation, is investigated using the MERRA2 reanalysis wind data and NAO and EA indices for 1980-2019. The composite method taking into account the nonstationarity of the time series of the NAO and EA indices is used. It is shown that in some months of the summer-autumn period during the positive phase of NAO, there is a significant increase in the cyclonic WSC over the eastern part of the sea. The highest influence of the EA on the WSC over the Black Sea is observed in November to April: during the negative EA phase, the cyclonic WSC increases over most of the Black Sea area. Such increase should lead to an intensification of the Black Sea water circulation. It is confirmed that the EA has a greater effect on the WSC over the Black Sea than the NAO.