The influence of circulation factors on the quantity of atmospheric precipitation in the cold season in Western Siberia

Abstract

Introduction. The work is devoted to the analysis of the influence of different states of the circumpolar vortex on local features of the geopotential fields, which, in turn, determine the variability of cold season precipitation for the studied territory of Western Siberia. Data and Methods. A statistical analysis of time series of seasonally average values of the precipitation amount in the cold season was performed, obtained from 33 meteorological stations located within the selected coordinate area. To analyze the distribution of hydrometeorological fields corresponding to different states of the circumpolar vortex, composite spatial distributions corresponding to the ten most typical years for both phases of the POL teleconnection index were constructed. Results and Discussion. A statistically significant relationship was established between the amount of precipitation in the cold season (November–March) on the studied territory and the state of the circumpolar vortex. It was shown that under the conditions of the negative phase of the POL index, the amount of precipitation in the cold season is greater than under the conditions of the positive phase of this index. Conclusions. Based on the results of the work, it was concluded that under conditions of a weak circumpolar vortex and developed meridional processes (negative phase of POL) in the studied area, the amount of atmospheric precipitation in the cold season is greater than under conditions of a strong (positive phase of POL) circumpolar vortex and active latitudinal processes.

Keywords

• cold season precipitation
• circumpolar vortex
• intensity of interlatitudinal exchange
• western siberia
• regional climate change