Spatio-temporal variability of atmospheric impurities over Lake Baikal during the expeditions to the SRV V.A. Koptyug in 2019

Abstract

Route observations were carried out aboard the SRV Akademik V.A. Koptyug on study of the spatio-temporal variability of small gas imp_uriti_es (O₃, NO2, SO2) at Lake Baikal. The spatio-temporal variab_ility of O₃, NO2, SO2 is extremely heterogeneous over the lake. Under conditions of the formation of a stable air mass in the warm sector of cyclone, high daytime air temperatures and elevated concentrations of surface ozone up to 120 g/m3, sulfur dioxide (up ^to 30 g/m3) were observed. The concentrations of nitrogen oxid_es (NO, NO2) did not exceed the background values. It is shown that in the water area of the lake the content of nitrogen dioxide is much lower than that of sulfur dioxide. A comparative analysis of the results of measurements of small gas imp_uriti_es SO2, NO2 over the water area of the lake and at the coastal station showed that with long-distance transport of anthropogenic impurities, gaseous nitrogen oxides usually transform into nitrates due to a higher _rate of NO2 oxidati_on than SO2.