Eleventh International Conference on Climate Change: Impacts & Responses

Abstract

Long-term fluctuations of the global atmospheric circulation and air temperature over the period 1899-2017, as well as weather extremes and the dangerous natural processes that are formed on their basis in the world and in Russia in the 21st century have been studied. The classification of the global atmospheric circulation was developed on the basis of the atmospheric circulation classification in the Northern Hemisphere by BL Dzerdzeevskii, VM Kurganskaya and ZM Witwitskaya. The same three circulation epochs are distinguished as for the Northern Hemisphere, as the periods with the greatest positive deviations of the total annual duration of one circulation group from the average multiyear value. Against the backdrop of secular fluctuations, the features of atmospheric dynamics in the 21st century are considered. During this period, the maximum meridional transport of air masses is observed in the lower troposphere. Macro processes with cyclones at the poles, with three or four simultaneous cyclone outlets from low latitudes in three or four sectors of the hemispheres are followed by macro processes with anticyclones at the poles, cyclone outlets from low latitudes in two or four sectors of the hemispheres, and Arctic / Antarctic intrusions in their rear , which form blocking processes. The global average annual air temperature follows the variations in the atmospheric circulation. Simultaneous cyclones outlets from low latitudes in different sectors of the hemispheres cause simultaneous occurrence of dangerous natural processes associated with abundant precipitation in different regions. The types of circulation under which this occurs are revealed.