DRYNESS DYNAMICS OF THE SOUTH OF EUROPEAN RUSSIA IN THE SPRING - SUMMER PERIOD
Changes in the characteristics of spring-summer droughts in the south of European Russia (twelve regions) in the period 1901-2018 were studied using the Standardized Precipitation Index (SPI) and analyzed in the periods of increasing/decreasing humidifying estimated by the Aridity Index (AI). In each studied region, the trends of aridization for centrury and more are not found. In the meantime, long-term interdecadal periods of increasing and decreasing aridization are detected. They are characterized by significant variation of frequency and intensity of spring-summer droughts. Decreasing aridization in the early 20th century over most of the south of European Russia has been replaced by aridization increase in 1930s. The period of increasing humidifying of the whole investigated area from 1960s to the end of 20th century changed to the period of increasing aridization. During dry periods, frequency of drought increases in 1.5 times, while drought intensity growth is insignificant. In actual dry period, beginning with the early 21th century, spring-summer droughts have emerged earlier in eastern part of South of European Russia; however, in western part drought are observed more often.