Assessment of smoke aerosol contribution to atmosphere of the south-eastern coast of Lake Baikal in 2021 ("Boyarsky" station)

Abstract Smoke aerosols emitted by wildfires can ascend into the free troposphere, be transported over long distances, and subsequently descend, thereby affecting local air quality in remote areas. This article presents a study of aerosol pollution in the atmosphere over the southeastern shore of Lake Baikal during the summer of 2021, utilizing an automated system for real-time air quality monitoring. Analysis of mass concentrations of fine particulate matter fractions PM₁₀ and PM2.5, aerosol optical depth (AOD) measurements, aerosol sampling, and backward air mass trajectory analysis using the HYSPLIT model demonstrated that the prolonged atmospheric turbidity over Lake Baikal was caused by the transport of smoke aerosol from large-scale wildfire centers in the Republic of Sakha (Yakutia) and Siberia. Two prolonged smoke aerosol intrusion events, transported from Yakutia between July 26 and 29 and August 7 to 14, 2021, were analyzed. During these periods, smoke aerosols were entrained into the planetary boundary layer and accumulated near the surface due to temperature inversion conditions.