Synoptic Conditions for Ablation of the Sygyktinsky Glacier (Kodar Range)

The influence of synoptic conditions on a 700-hPa isobaric surface on meteorological conditions and melt of the Sygyktinsky glacier (Kodar Range) in 2021 ablation season was studied. Fifteen weather types were classified using the Jenkinson and Collison method; cyclones (24%) and anticyclones (20%) were found to be the most frequent types. A significant dependence of the meteorological conditions at the glacier on the weather type was revealed. High temperatures and low relative humidity and cloudiness are typical for anticyclonic types, and vice versa, for cyclonic types. The radiation regime at the glacier and its melting rate were found to depend on synoptic conditions. The maximal contribution to melting is made by anticyclonic weather types (44% of total ablation), and the minimal, by cyclonic types (26%). The net radiation of the glacier is 2–2.5 times higher and the ablation rate is 1.6–1.8 times higher in anticyclones than in cyclones. The differences between the fluxes of energy spent for glacier melting under different weather conditions are explained by cloudiness. The different atmospheric circulation regimes over the Kodar significantly affected the deglaciation of the Kodar glaciers in recent decades. The results of our work will help to predict future climate changes in mountain glaciers.