Distribution of Aerosol Particles in Leningrad Oblast along the Wind Direction from St. Petersburg

The article presents the results of lidar measurements of the distribution of aerosol particles at a distance from St. Petersburg along the path of wind direction in order to assess the transport and dispersion of aerosols formed over St. Petersburg and adjacent regions. The measurements were carried out by the mobile lidar complex of the Observatory of Environmental Safety Resource Center of the Saint Petersburg State University Science Park. The measurements were carried out with wind and aerosol lidar, which made it possible to control both the wind direction and the content of the aerosol component. The measurements were carried out in the summer and autumn seasons in 2024, during the daytime. The maximum content of aerosol particles was observed in the boundary layer of the atmosphere at an altitude of up to 1 km. The maximum amount of aerosol particles in an air column from 350 m to 2 km with an area of 1 cm2 was observed at sites closest to the city, with a total aerosol content of 300 to 400 million particles. As the air mass moves away from the city, the number of particles in the air column decreases. The decrease in aerosol particle concentrations between observation sites is in the range of 0.5–3.3 million particles per kilometer. A decrease in the aerosol content indicates dispersion and precipitation of aerosol particles, as well as the absence of significant additional sources of emission along the path of the air mass.