MODERN TRENDS IN VARIABILITY OF AVERAGE AND EXTREME SNOW DEPTH VALUES ON THE EAST EUROPEAN PLAIN
L.M. Kitaev, T.B. Titkova, M.A. Aleshina
Institute of Geography, Russian Academy of Sciences, Moscow, Russia
Keywords: snow thickness, air temperature, precipitation, percentiles, minimum and maximum extremes, regression analysis, seasonal and long-term variability
Abstract
The variability of average and extreme seasonal snow depth values on the East European Plains has been assessed taking into account regional characteristics of the meteorological regime. The regional distribution of average and extreme (5th and 95th percentiles, minimum and maximum extremes) snow depth values has been clarified. A tendency for a long-term decrease in the average and extreme snow depth values with an increase in air temperature and precipitation has been revealed. According to the results of regression analysis, the dependence of long-term dynamics of snow depth on meteorological characteristics is more pronounced for maximum extremes. The most significant contribution to changes in the snow cover depth belongs to the variability in precipitation. The difference integral curves indicate the presence of two negative phases of snow depth characteristics in 1985-1995 and 2005-2015, which corresponds to the long-term features of atmospheric circulation. Based on data from reference weather stations, the accuracy of snow depth calculations using ERA 5-Land reanalysis has been estimated: the relative error reaches 45-50 %, and linear trend coefficients differ by 1.5-3 times, which should be taken into account when using the calculated values.
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