Characteristics of annual behavior of spectral aerosol optical depth of the atmosphere under conditions of Siberia.
Based on the many-year observations in Tomsk (since 1995 in wavelength range 0.37-4 μm) and other regions of the Asian part of Russia (2003-2008), we determined the specific features in the annual behavior of characteristics of the spectral aerosol optical depth (AOD) of the atmosphere. It is shown that the maxima of AOD are observed in April (0.19 in the region 0.5 μm) and July, local minimum (less than 0.16) in June, and minimum values (0.12) in fall. The seasonal variations of the Angstrom selectivity parameter is characterized by elevated values in the warm period (maximum in July) and low values in winter. We indicated the closeness of the seasonal variations of aerosol turbidity in three Siberian regions and suggested Siberia-mean annual behavior of the AOD characteristics. Average values of the optical and microphysical aerosol characteristics of the atmospheric depth are presented for characteristic periods of intra-annual AOD variations.