Estimation of Source-Based Aerosol Optical Properties for Polydisperse Aerosols from Receptor Models

Abstract

We estimate source-based aerosol optical properties for polydisperse aerosols based on a source apportionment-based chemical species-resolved mass contribution method. We investigate the sensitivity of aerosol optical properties based on the PM2.5 monitoring results collected at the Korea Institute of Science and Technology, Seoul, Korea, from October 2012 to September 2013. The PM2.5 mass concentration data is composed of ions, metals, elemental carbon, and water-soluble organic carbon, which includes humic-like carbon substances and organic carbon that is water-insoluble. We calculate the aerosol extinction coefficient based on the PM2.5 composition data and the results of a multivariate receptor model (SMP, Solver for Mixture Problem). Using calculated optical properties based on the chemical composition of the resolved mass concentration and nine sources from the SMP receptor model, we estimate size-resolved mass extinction efficiencies for each aerosol source using a multilinear regression model. Consequently, this study quantitatively calculates the size-resolved source of the apportionment-based aerosol optical properties and their respective contributions. The results show that source-resolved mass concentrations and extinction coefficients have varying contributions. This discrepancy between the source-based mass concentration and extinction coefficient is mainly due to differences between each source-based aerosol size distribution and the aerosol optical properties from different sources.