Lake Baikal—a unique ecosystem on a global scale—is undoubtedly of great interest for a comprehensive study of its ecosystem. In recent years, one of the most significant sources of atmospheric pollution in the Baikal region was the emission of smoke aerosol and trace gases from forest fires, the number of which is increasing in the region. The transport and accumulation of aerosol and small gas impurities over water area of Lake Baikal is observed every summer due to forest fires occurring in the boreal forests of Siberia. The atmosphere above the lake covers a huge area (31,500 km²) and is still a little-studied object. This article presents the results of experimental studies of ground-level ozone, sulfur dioxide, and nitrogen oxides in the atmosphere over Lake Baikal, carried out on a research vessel during the boreal forest fires in Siberia in the summer of 2019.

Forest ecosystems play an important role in the process of removing trace gases from the atmosphere. The purpose of this work is the experimental study of the flux and rate of the dry deposition of ozone on different types of vegetation in the Baikal region. Based on the eddy covariance method and the flux gradient methods (including the aerodynamic gradient method (AGM), the modified Bowen method (MBR) and modified gradient method (MGM)) and with experimental data, the quantitative estimates of the fluxes and dry deposition velocity of ozone on the underlying surface were obtained for different environments (grasslands, forest). The average values of the dry deposition velocity of ozone (V_d) were equal to 0.37 cm/s at night (0–3 h) and 0.91 cm/s during daytime hours (12–18 h). The ozone flux (F) was 0.24 μg m^–2 s^–1 at night and 0.72 μg m^–2 s^–1 in the afternoon. The quantitative estimates of V_d and F on vegetation and in the forest show a higher absorptive capacity of forests compared to soil vegetation.

Description of gradient measurements of atmospheric trace gases concentrations and dynamic characteristics of atmosphere on the southeastern coast of Lake Baikal is given. The measurements were performed at the Boyarsky stationary site (51.84° N, 106.06° E) using a 30-m meteorological mast. The results of experimental studies of the diurnal dynamics of atmospheric trace gases concentrations, meteorological and turbulent parameters of the atmosphere at different altitudes are described.