The results of the analysis of variations of aerosol optical thickness of atmosphere in Ulan-Ude during four year (2006-2009) observations by means of sun photometer SP-7 are presented. Seasonal features of spectral dependences of aerosol optical thickness and the total humidity of atmosphere are discussed. The high aerosol turbidity of atmosphere for Ulan-Ude in winter in distinction from most stations of Siberia is observed. Comparisons of average spectral dependences of aerosol optical thickness and the total humidity of atmosphere in Ulan-Ude with measurements on Lake Baikal coast (station Boyarsk) and other stations of the Asian part of Russia are made.
aerosol optical thickness, columnar water vapor, seasonal features