Absorption Coefficient of the Vienna Aerosols: Comparison of Two Methods

Abstract

The absorption coefficient of the atmospheric aerosol over Vienna has been determined by two independent methods: the integrating plate method and by subtracting the light scattering coefficient obtained with an integrating nephelometer from the light extinction coefficient obtained by telephotometer. The raw data are highly correlated and, both for the summer aerosol with an average 20% light absorption and for the winter aerosol with an average of 40% light absorption, they agree almost perfectly. When considering small corrections owing to truncation in the nephelometer, the light absorption measured by the integrating plate is consistently too high by 30%–40%. This is in agreement with previously published results for other locations.