Inter-Decadal Variability of the Wind Mode in the Black Sea Region

The surface pressure over the Black Sea in January-March, 1948-2012 is considered in the present article. The obtained climatic atmospheric pressure trends in this area reflect the relevant trends in the atmospheric circulation variability. It is shown that since the second half of the twentieth century, the North Atlantic Oscillation index (NAO), which characterizes the atmosphere circulation over Europe, showed the trend to the growth, where since the 1950's in the winter season was dominated by the zonal transfer in the atmosphere over Europe. At that the Black Sea region was mainly in the anticyclonic circulation area. It was found that the negative phase of the NAO surface the pressure oscillations over the western part of the sea were more than the average multi-annual one, than over its eastern part, and in the positive phase of the NAO - less. Analysis of the spatial variability of anomalies of surface wind speed module in the Black Sea region showed during the even cycle, i. e. when the positive phase of the North Atlantic oscillation (NAO) index is mainly predominant, negative anomaly of the wind speed module is formed over the western part of the sea, whereas positive one -over the eastern part. The marked negative trend in wind speed module on coastal hydrometeorological stations confirms the trend to an increase in the influence of the Azores and Siberian anticyclone in the pressure field of the Black Sea region. Taking into account the positive phase of NAO is advantageously implemented during the even solar cycle and the negative one - during the odd cycle. It was found that in the even years of the cycle the maximum surface wind speed is observed over the eastern part of the Black Sea, the lowest one - over the western part. During the odd cycle of solar activity the signs of the surface wind anomaly modules above the western and eastern parts of the sea are changed into opposite ones.