Synoptic Conditions for Dry Winds in August 2010 in Ukraine

Dry wind is a widespread dangerous phenomenon, which reduces the yield of crops in Ukraine.

The aim of this study is to determine the conditions of the atmospheric circulation leading to the formation of dry winds in August 2010 and to determine the effect of these conditions on the distribution of dry winds in Ukraine during this period. Daily observations at 24 meteorological stations for the period from 31 July to 31 August 2010 were used, as the initial dataset. To define the location where the formation of initial dry wind air mass begins, backward trajectories for the previous movement patterns of air particles were constructed for period of a 120 hours (5 days) for the following heights: earth surface (0 m nominal), 1500 m and 3000 m for stations where the phenomenon was observed. During this period dry winds were observed in different parts of Ukraine, and the longest multi-day dry wind in period from 1995-2015 was observed at Mariupol station, from 31July 2010 to 20 August 2010, lasting 21 days. In first half of August 2010, air masses came from regions of northwestern Kazakhstan, the Ural Mountains, and the east and northeast of European Russia. After a blocking anticyclone over European Russia was dissipated, the baric field was reorganized, and territory of Ukraine was under the influence of the western air masses. After the development of an anticyclone over Central Europe at each heights, air masses came from the west from Central and Western European regions, and the North Atlantic.

The spread of dry winds over Ukraine occurred against the backdrop of the formation in the European sector of meridional of atmospheric circulation, with the development of a blocking process over European Russia. The development of dry conditions was facilitated by the stable, clear weather, without precipitation for a long time, as well as the descent of air masses in an anticyclone system, leading to their adiabatic heating.