Water Balance of Belarus and Its Changes due to Global Warming

Abstract

Estimates of the water balance components (precipitation, evaporation, zonal and meridional advection of moisture) on the territory of Belarus for the cold (October–March) and warm (April–September) seasons have been obtained on the basis of the balance calculations of precipitation recycling and the ERA5 reanalysis data. It has been shown that the precipitation on the territory of Belarus results from westerlies in 77–84% of cases, from southerlies in 14–20% of cases, and from local evaporation in 2–4% of cases. Annual total precipitation exceeds annual evaporation by 18–30% (the maximum excess is observed in the north, and the minimum is registered in the southeast). During the warm seasons, there is a negative water balance in entire Belarus: evaporation exceeds precipitation by 8–23%. Over the period of global warming, the annual difference between precipitation and evaporation has decreased by 12–15%. The water balance for the warm season has decreased to negative values at the beginning of the current century due to the activation of summer warming. An increase in the amplitude of the water balance fluctuations has been revealed for the cold season, which indicates strengthening climate extremity.