Variability of Climatic Characteristics and Their Relationship to Large-Scale Atmospheric Circulation over Siberia.

A study is made of the changes in climatic characteristics such as air temperature, atmospheric pressure, and precipitation and their relationship with the large-scale atmospheric circulation over Siberia for the climatically significant time interval of 1979‒2018. The study area is limited to 50°‒70° N and 60°‒110° E. Daily observational data from NOAA GSOD are used in calculating the series of territory-averaged values of surface temperature, atmospheric pressure, and average precipitation. The characteristics of baric formations of cyclones and anticyclones are determined on the basis of surface synoptic maps for standard meteorological periods. It is found that, by the end of the study period, the trend in surface temperature and precipitation is positive and the trend in atmospheric pressure is negative. The trend in characteristics of baric formations, such as the number of cyclones and anticyclones, is positive, as is the pressure trend in the centers of anticyclones. On the contrary, the pressure trend in the centers of cyclones is negative, as is the trend in the duration of the impact of cyclones and anticyclones. It is shown that these trends underwent the most dramatic changes during 2012‒2018, with a change of sign of the trend in pressure in the centers of anticyclones. Taking into consideration the close relationship between climatic characteristics and large-scale atmospheric circulation, it can be suggested that the warming in Siberia before 2012 was due to a weakening of anticyclonic activity and after 2012 it was due to an increase in cyclonic activity. [ABSTRACT FROM AUTHOR]