Extreme Drought on the Eastern European Plain during the Early 20th Century Warming: Climate Characteristics and Analogues under the Conditions of Modern Climate

The unprecedented anomalies of the annual runoff of the Volga and the Northern Dvina rivers in 1920–1940s are considered in the context of global warming in the mid-twentieth century and climate extremes of recent decades. The analysis of climate characteristics demonstrates that the global temperature rise during a given period manifested itself in the long-term drought in 1934–1940s on the Eastern European Plain, which, according to Palmer’s classification, has no analogues in the region in terms of intensity and duration and caused extreme hydrological events. The results of the spectral analysis of the river runoff variability, as well as the analysis of empirical orthogonal functions of atmospheric pressure anomalies, suggest that the droughts of 1972 and 2010 can be considered as the closest similar phenomena, but significantly inferior in their impact on the natural environment.