Variations of Aerosol Optical Thickness of the Atmosphere in Russia in 1976–2003

I. N. Plakhina, E. L. Makhotkina, and N. V. Pankratova

Space-time variations of aerosol optical thickness of the atmospheric column are analyzed on the basis of observational data of the Russian actinometric network in 1976–2003. From the measured direct solar radiation flux and air humidity for 44 stations in European and Asian Russia, spectral aerosol optical thickness (AOT) of the atmosphere is estimated for a wavelength λ = 0.55 _m. Interannual, seasonal, and space variations of AOT are estimated. Effects of eruptions of the volcanoes El Chichon (April 1982) and Pinatubo (June 1991) are considered. For most stations, a negative tendency is found in the AOT interannual changes, which is more pronounced in spring and summer. It is shown that the period after the Pinatubo eruption is characterized by “purification” of the atmosphere from aerosol.