Slizhe M. Meteorological characteristic and aerosynoptical conditions of dry wind development in Ukraine

The dissertation is devoted to the determination of the peculiarities of the spatial-temporal distribution of dry winds and their meteorological characteristics in 1995-2015 on the territory of Ukraine, as well as the establishment of features of regional synoptic processes, which leads to the emergence of dry winds in this area in recent decades. A database of dry winds data for the period from April to August 1995-2015 for 24 meteorological stations of Ukraine is compiled. The analysis of spatial-temporal distribution of dry winds in the investigated period and its seasonal peculiarities in different agro-climatic zones of Ukraine is carried out. The comparative analysis and changes in the repeatability of dry winds at 14 meteorological stations from April to August 1995-2015, 2005-2014 in relation to the 1936-1964 and 1945-1964 were completed. The analysis of air temperature regime and relative humidity at the investigated stations in dry wind periods and the features of their seasonal and daily changes in different agroclimatic zones were determined. An analysis of the regime of speed and direction of dry winds in recent decades has been carried out, the prevailing wind directions at stations in dry wind periods have been determined, and their changes during the growing season. The structural features of regional pressure fields, in which dry winds appeared on the territory of Ukraine in recent decades, have been determined. The backward trajectories of the previous movement of air particles were constructed for the period of 120 hours (5 days) for the following heights: at the earth`s surface, 1500 m and 3000 m we used. The origin regions of air masses that acquire in the territory of Ukraine of the dry wind properties are established. The seasonal changes in the repeatability of trajectory types and the features of the distribution of repeatability of trajectory types in different agro-climatic zones are determined. The individual changes in temperature, potential temperature, relative humidity for air particles and the magnitude of their vertical displacement were calculated. The analysis of the interday individual changes in temperature and the potential temperature of air particles for different trajectory types is carried out. An estimation of the change in the temperature of air particles due to adiabatic vertical displacement, and its contribution to the individual temperature change is performed. The advective changes of air temperature and relative humidity at meteorological stations during dry wind are calculated. The drought periods in 1995-2015 at the meteorological stations under study were determined with using the index SPEI, and a comparative analysis of the occurrence of dry winds and droughts with statistical estimation of the connection between these phenomena were completed.