Some meteorological aspects of severe agricultural drought in the Northern Black Sea region in 2019-2020

The regions of Odesa, Mykolaiv and Kherson, which are located in the southwest of Ukraine and occupy the Northern Black Sea region, have been affected by severe drought occurred in 2019-2020 with catastrophic impact on agriculture sector in 2020.

An overview of the meteorological and synoptic conditions for the formation of this drought showed that the combination of several adverse factors influenced on evolution of drought for a long time.

Analysis of the time course of the drought index SPI on 1 month time scale showed that after relatively favorable spring months at the different points of the Odessa region, the deficit of precipitation (SPI < 0) was observed almost at all months in 2019 (except October), and continued in the first months of 2020.

Analysis of the spatiotemporal distribution of the anomalies of satellite-derived vegetation index NDVI in March-October showed that in 2019, the positive anomalies were observed only in the spring months, but since the beginning of summer and until the middle of the autumn, an increase in the negative anomalies of the NDVI index was observed. March 2020 was characterized by favorable conditions for the vegetation, however, in April, the anomalies of NDVI became negative and reached the minimum in May.

As shown, during months of 2019 in the middle troposphere the monthly positive anomalies of the geopotential heights prevailed in average, which reached maximum values in the second half of 2019 and in January 2020. Analysis of the time course of the ECBI (European continental blocking index) showed that the most prolonged periods of blocking over the European continent were observed in March-April, August-September and November 2019 (from three to six consecutive pentads), as well as in December 2019-January 2020 (four consecutive pentads).