UDC 551.5; 58.032.3
Popova V.V., Bokuchava D.D., Matveeva T.A. EXTREME DROUGHT ON THE EAST EUROPEAN PLAIN DURING THE HEAT WAVE IN THE MIDDLE OF THE 20th CENTURY: CLIMATIC CHARACTERISTICS AND ANALOGUES IN THE MODERN CLIMATE CONDITIONS // Arid Ecosystems. 2023. Vol. 29. № 2 (95). P. 3-11. | PDF
The unprecedented annual flow anomalies of the Volga and the Northern Dvina rivers in 1920-1940 are considered in the context of global Early 20th Century Warming (ETCW) and climate extremes of recent decades. The study of hydrological and climatic characteristics reveals that the ETCW period manifested itself on the East European Plain in the long-term drought in 1936-1940, that, according to Palmer drought severity index, has no analogues it terms of intensity and duration in this region. The results of the cross-spectral analysis of the variability of river flow and the North Atlantic Oscillation index, as well as the analysis of empirical orthogonal functions of the surface level atmospheric pressure anomalies indicate the relationship of the hydroclimatic extremes of the period considered with anomalies of the North Atlantic atmospheric circulation and the positive phase of the Atlantic multidecadal Oscillation (AMO).
In terms of intensity, duration and impact on river flow, the dry period from the late 1960s to the mid-1970s, with a maximum of 1972, can be considered as the most similar analogue to the drought of the 1930s. In the spectrum of the annual Volga River runoff, the anomaly of the 1972 manifests itself as the second rate maximum of the runoff variance after the absolute maximum of the 1930s. From the point of view of the atmospheric circulation conditions and links with the positive phase of the AMO, the extreme heat and drought of 2010 can be recognized as an analogue of droughts in the period of the ETSW. At the same time, it is different by the absence of significant consequences for river runoff due to the increase in precipitation of the cold period during the period of modern climate warming.
Keywords: warming of the mid-twentieth century, East European Plain, river runoff, extremes, drought, Palmer index, circulation conditions.
Funding. The study was carried out for the Russian Scientific Foundation project No. 22-27-00495 “Climatic and Circulation Factors of Anomalies of Humidification of Large River Basins of European Russia in the Era of Warming of the Mid-twentieth Century”.