Variability of the aerosol microstructure under the forest fire smoke effect retrieved from spectral characteristics of light extinction in the near-surface air layer and the atmospheric column
V.V. Veretennikov, S.S. Men'shchikova, V.N. Uzhegov
V.E. Zuev Institute of Atmospheric Optics of Siberian Branch of the Russian Academy of Science, Tomsk, Russia
Keywords: ослабление света, микроструктура аэрозоля, дымы, обратные задачи, регрессия, extinction of light, aerosol microstructure, smoke, inverse problem, regression
Abstract
The features of the aerosol microstructure are investigated in the near-surface layer and vertical column of the atmosphere when smoke enters the atmosphere. The aerosol microstructure parameters were determined by solving the inverse problem for spectral measurements of the aerosol extinction coefficient using the base method, and of the aerosol optical thickness, using the solar photometry method in the clean atmosphere and under conditions of the smoke-polluted atmosphere near Tomsk. The geometric cross section, volume concentration, and mean radius of aerosol particles of submicron and coarse fractions were calculated. For background conditions, the coarse fraction prevails in the total volume of the aerosol. The submicron fraction becomes dominant under the condition of the smoke-polluted atmosphere. As a result, the particle radius averaged over the total ensemble decreases in the smoke-polluted atmosphere. The regression relations between the microstructure parameters of different aerosol fractions and the spectral characteristics of the light extinction significantly change in the smoke-polluted atmosphere.
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