Synoptic processes over the Kodar glacier zone during the ablation period

Abstract

The small glaciers of the Kodar ridge (south of Eastern Siberia), located inland Asia under the influence of both Atlantic and Pacific air transport, are the valuable objects for studying their response to changes in mid-latitude atmospheric circulation. However, detailed meteorological studies on the glaciers have been limited so far. For the first time, in July–August 2019, the meteorological characteristics were measured on the Sygyktinsky glacier using automatic weather station. We have analyzed the relationship between variations of large-scale atmospheric circulation and meteorological regime of the glacier using the NCEP–NCAR reanalysis data. During the observation period, Kodar was under the influence of a positive geopotential anomaly in the lower troposphere, which determined increased temperatures and decreased relative humidity and precipitation. Quasi-cyclic fluctuations in meteorological time series (e.g. air temperature) reflect the influence of large scale synoptic changes caused by the front passages, warm and cold air advections. High ablation rates on the glacier were associated with anticyclones, subtropical ridges, and warm air advections (from southeast and southwest), while decreased ablation was observed during the cyclone passage and cold air advection (from north, northeast, and west).