Aerosol light absorption measurement techniques: Analysis and intercomparisons

Abstract

A controlled study was carried out to evaluate three measurement techniques used for the determination of aerosol light absorption coefficients from aerosol samples collected on various filter substrates. These techniques were found to agree within about 10–30% when applied to a range of filter loading obtained for a laboratory generated calibration aerosol. Microphysical properties of the calibration aerosol were used to model its optical effects using Mie theory. The measured and modeled optical properties were found to differ by less than 30%. Qualitative and quantitative agreement of these techniques indicate that they provide a reasonable indirect method for the determination of atmospheric aerosol absorption coefficients and the related concentration of elemental carbon aerosol.