Long-term variations in the processes of polluting the Arctic atmosphere

Variations in the processes of atmospheric circulation in the Russian Arctic were studied during 20 years from 1981 through 2000. During this period, air exchange between northern Russia and Eurasia gradually decreased, and the probability of air mixing within the Arctic region increased. This resulted in a redistribution of the contributions of large industrial source regions to the content of anthropogenic microelements in the Arctic atmospheric aerosol. Moreover, during the processes of purifying the Arctic atmosphere, the importance of pollutant precipitation onto the underlying surface was increased, and the importance of pollutant removal by air masses outside the Arctic region was decreased. This resulted in variations in the mean atmospheric concentrations and fluxes of a number of heavy metals and other toxic microelements onto the underlying surface. In particular, during spring, the mean concentrations of anthropogenic constituents in the aerosol over the central region of the Russian Arctic decreased gradually only because of changes in the processes of atmospheric circulation. If a decrease of the intensity of anthropogenic emissions occurring in Europe and in the industrial regions of the former Soviet Union in the 1990s is taken into account, the annual average fluxes of anthropogenic pollutants onto the underlying surface of the Arctic had to a] so have been decreased at the end of the last century. On the whole, in the Northern Hemisphere, global warming must gradually decrease the efficiency of transport of anthropogenic pollutants by air masses from large industrial regions to the Arctic and, thus, decrease the importance of the atmosphere as a channel through which pollutants enter the Arctic region.