Abstract <p>The problem of aerosol pollution of the atmosphere and associated climate change has become increasingly relevant. Of particular interest are physicochemical properties and structure of atmospheric aerosols. Being an important component of polluted air, aerosols affect various atmospheric processes, the environment, and human health. Analysis of the morphology and composition of aerosol particles enables us to identify the features of their behavior in the atmosphere and determine their origin. This paper studies the composition and morphology of near-surface atmospheric aerosol particles at a year-round monitoring station (Irkutsk) in different seasons of 2024 using scanning electron microscopy and X-ray spectral analysis. The main types of aerosol particles (soot, fly ash, mineral, and biogenic particles) are identified, and their shapes and sizes are determined. It has been established that mineral and biogenic particles predominate in the composition of near-surface atmospheric aerosol in Irkutsk during the warm season, while fly ash and soot particles predominate during the cold season. Brochosomes (fullerene-like structures of biological carbon-containing particles) were detected for the first time in the surface aerosol at the urban Irkutsk station. The results of this study expand our understanding of the morphological properties and composition of individual particles in surface atmospheric aerosol in the urbanized area of the Southern Baikal region.</p>