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.

The atmosphere over Lake Baikal covers a vast area (31,500 square meters) and has more significant differences in the composition and variability of gaseous and aerosol components in atmospheric air than in coastal continental areas and is still a poorly studied object. In recent years, the anthropogenic impact on the ecosystem of Lake Baikal has been increasing due to the development of industry in the region, the expansion of tourist infrastructure and recreational areas of the coastal zone of the lake. In addition, one of the significant sources of atmospheric pollution in the Baikal region is the emissions of smoke aerosol and trace gases from forest fires, the number of which is increasing in the region. This article presents the results of experimental studies of the dispersed composition of aerosols and gas impurities, such as ozone, sulfur dioxide, and nitrogen oxides during route ship measurements in the water area of Lake Baikal in the summer of 2020.

The results of an experimental study of ultrafine aerosol characteristics in the Baikal region and the Gobi Desert are described. The comparative analysis of the dispersion composition of atmospheric...

The paper analyzes the interannual, seasonal variations of the optical and microphysical characteristics of aerosol in the Baikal region atmosphere according to measurements using the CIMEL sun photometer of the AERONET network at Tory station and according to the data of expedition measurements using the SP-9 sun photometer on the southeastern coast of Lake Baikal from 2010 to 2020. It is shown that in recent years, there has been an increase of the average monthly aerosol optical depth (AOD) values in the summer months, which is consistent with an increase in smoke emission due to annual large-scale wildfires in the boreal forests of Siberia and Yakutia in summer. Aerosol classification was carried out based on filtration and selection of the prevailing types of aerosols by analysis of aerosol optical depth and Angstrom exponent. It was revealed that in summer, the proportion of the smoke component of the aerosol optical depth increases to 30% compared to the spring. In the presence of smoke advection, the close relationship of AOD with the concentrations of the microdispersed aerosol fraction PM₁₀ and PM_2.5 was revealed. The correlation coefficients between the concentration of particulate matter (PM₁₀ and PM_2.5) and AOD were 0.87 and 0.86, respectively.

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.

In recent years, the role of the atmosphere in the formation of the chemical composition of water in Lake Baikal and its tributaries has been increasing. In this regard, the study of equivalent black carbon (eBC) in the air above the lake and its coast has an important practical application. This paper presents the results of the mass concentration of eBC and submicron aerosol in the air above the water area of Lake Baikal, which were obtained during expeditions onboard research vessels in the summer of 2019 and 2023. We analyzed the data from the coastal monitoring station Listvyanka. To measure eBC, an MDA-02 aethalometer was used in the water area of the lake, and a BAC-10 aethalometer at the Listvyanka station. The background level of the eBC concentration in the air at different areas of the lake ranged between 0.15 and 0.3 µg m⁻³. The results of the two expeditions revealed the influence of the coastal settlements and the air mass transport along the valleys of the lake’s large tributaries on the five- to twentyfold growth of the eBC concentration in the near-water atmosphere. In the diurnal dynamics of eBC near settlements, we recorded high values in the evening and at night. In background areas, the diurnal dynamics were poorly manifested. In the summer of 2019, there were smoke plumes in the water area of Lake Baikal from distant wildfires and a local fire site on the east coast of the lake. The eBC concentration increased to 5–6 µg m⁻³, which was 10 to 40 times higher than the background. The long-range transport of plumes from coal-fired thermal power plants in large cities of the region made the major contribution to the eBC concentration at «Listvyanka» in winter, which data on aerosol, gas impurities, and meteorological parameters confirmed.