Trends in Atmospheric Aerosol Characteristics in Moscow Derived from Multiyear AERONET Measurements

Abstract

We estimated the trends of aerosol optical depth (AOD) in Moscow over 2002–2016 using ground-based AERONET measurements. Negative AOD trends were found. It is shown that AOD trends differ depending on month; the most negative trend is observed in April if neglecting the effect of forest fires. Variations in AOD and atmospheric circulation indices are jointly analyzed. It is shown that Scandinavian index has an additional effect on interannual AOD variations in April. The predominant aerosol type (recorded in more than 60% of observations) for the territory of Moscow is fine-fraction weakly absorbing aerosol. No directional changes in aerosol types have been observed in recent decades.