Estimate of the Urban Effect on Aerosol Turbidity of the Atmosphere according to Data of Two-Point 'Background-Industrial City' Measurements

摘要

We analyze the coupled measurements of the aerosol optical depth(AOD) and moisture content of the atmosphere in the Middle Urals, performed during the summer-fall period in urban(Yekaterinburg) and background(~65 km away) observation sites. In addition to AOD, we also considered the following char- acteristics of the atmospheric aerosol: the Angstrom parameters α and β, and the fine and coarse mode of AOD. It is found that the AOD value is almost unaffected by a coarse fraction of urban aerosol. A statistically significant difference is found in AOD values at all wavelengths in the range from 0.34 to 1.02 μm, in the Ang- strom selectivity exponent, and in the fine mode of aerosol optical depth, between the two sites. This indicates that there is an additional contribution of near-ground urban aerosol to the aerosol optical depth.