Long-range transport of plumes of atmospheric emissions from regional coal power plants to the South Baikal water basin

Abstract

We compare cases of actually observed regional transport of atmospheric pollutants to Lake Baikal against calculations according to a mathematical model. The observational data suggest that the most severe atmospheric pollution over the Lake is associated with atmospheric transport of sulfur and nitrogen dioxides from large coal-fired power plants both from the direction of Irkutsk and Angarsk, and from the direction of Buryatia (Ulan-Ude and Gusinoozersk). Transport of sulfur and nitrogen oxides to the Baikal atmosphere is especially strong at nighttime, under inversion-type meteorological conditions, in the form of weakly dispersed plumes from tall stacks of power plants. Data of automatic measurements of sulfur and nitrogen oxides demonstrate that actual mechanisms of anthropogenic pollutant transport to Lake Baikal are more complex and multiform as compared to model results. Model estimates of SO₂ concentrations over the Lake are close to monthly average measurements; however, they fail to explain certain specific cases of increased pollutant concentrations in the Baikal atmosphere.