Dynamics of snow cover in Kirovohrad region at the end of the XX and the beginning of the XXI centuries

Abstract

Snow cover significantly affects the formation of climate in winter. The snow over has low thermal conductivity, which protects the soil from freezing. In the spring, the snow cover significantly moistens the soil and plays an important role in the surface water regime and in the economic activity of the country. It should be noted that the lack or insufficient height of snow cover can be the cause of freezing of winter crops and their death, which leads to a decrease and even loss of yield. Accordingly, the increase in crop yields depends on the proper use of snow cover. The purpose of the research is to determine the characteristics of the snow cover and analyze their changes in Kirovohrad region in the late twentieth and early twenty-first centuries. Data of daily observations of snow cover at meteorological stations of Kirovohrad region for the period from 1996 to 2018 were used as primary information in the work. It is established that the appearance of snow cover at the stations of Kirovohrad region coincides in two periods (1961-1990 and 1996-2018) and was observed in the third decade of October at almost all stations, except for the area of data distribution of Dolynska weather station, where the first appearance of snow cover during 1961-1990 occurred in the first decade of October. The disappearance of snow in this period was observed in the third decade of April, in contrast to data from the climate cadaster, where 75% of stations observed snowmelt in the second decade of April, while at Dolynska station in the south of the region snowmelt occurred in the third decade of March. At Kropyvnytskyi station, located in the central part of Kirovohrad region, the appearance and disappearance of snow cover was observed in both periods on the same dates. In the period 1996-2018, the values of the highest decadal peaks for the winter were lower than in the climatic norm. The frequency of winters with the highest decadal height of snow cover in different gradations varies greatly in the study periods. For 1996-2018, the maximum was observed in the gradation of 1-5 cm; in the climatic norm the greatest recurrence is recorded in the gradation of 11-20 cm, significant indicators are observed in the gradation of 21-30 cm. The maximum recurrences of the decadal height of the snow cover are 100% and are determined in the gradation of 0-5 cm in both periods of snow cover.