Interannual and Seasonal Variations in the Atmospheric Aerosol Optical Depth in the Region of Tomsk (1995–2018)

Abstract

Seasonal and interannual variations in the atmospheric aerosol optical depth (AOD) are analyzed using multiyear (1995–2018) CE-318 (AERONET) and SP (Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences) sun photometer observations in the region of Tomsk. The annual behavior of AOD is characterized by a minimum in November and maxima in early May and in July. In the period 2009–2018, the annual behavior has been transformed so that the July maximum starts to dominate. In the interannual variations, we noted a significant negative trend of the coarse component of the total AOD. The annual average AOD (0.5 μm) is 0.155 (0.126 without accounting for smoke) and the Ångström exponent is 1.32 in the period of 2002–2018.