Aerosol Microstructure and Hygroscopic and Absorption Properties in the Atmosphere of Lake Baikal and Its Southern Coastal Territory in Summer 2024

Lake Baikal is a unique natural object. Study of the composition and optical characteristics of aerosols in the atmosphere above it is an urgent problem. This work analyzes the results of studies of the microstructural and physicochemical properties of near-water and near-ground aerosol in the atmosphere of Lake Baikal basin in summer 2024 onboard Research Vessel Akademik V.A. Koptyug and at the Boyarsky research station on the southeastern coast of the lake. The aerosol spatial distribution over the lake water area and the content of black carbon in aerosol particles are shown to be determined by the location of anthropogenic sources in the absence of smoke plumes from wildfires. Hygroscopicity and volatility of atmospheric aerosols, which depend on aerosol particle size, are studied for the first time. The aerosol condensation activity over the coastal zone is found to be stronger than over the lake. The results can be useful for the development of regional models of atmospheric aerosol.