Variations in Aerosol Microstructure under the Influence of Smokes from Forest Fires according to Inversion of Spectral Extinction Characteristics in the Near-Surface Layer and in Vertical Atmospheric Column

We studied the specific features of aerosol microstructure in the near-surface layer and in the vertical column of the atmosphere after smoke from fires enters the atmosphere. The aerosol microstructure parameters were determined by solving the inverse problem for spectral measurements of the aerosol extinction coefficient by the path method and aerosol optical depth by the sun photometry method in a clean atmosphere and during its pollution by smoke near Tomsk. The geometric cross section, volume concentration, and mean radius of submicron and coarse aerosol particles were calculated. The coarse fraction is typically predominant in the total volume of aerosol under the background conditions. The submicron fraction of aerosol particles becomes dominant after air is polluted by smoke. As a result, the particle radius averaged over the total ensemble decreases in the smoke-polluted atmosphere. Also, the character of regression interrelations between the microstructure parameters of different aerosol fractions and the spectral characteristics of aerosol extinction significantly change after the atmosphere is polluted by smoke.