Comparison of aerosol type classification during the MAPS-Seoul campaign in South Korea

To monitor the aerosol optical properties during the Megacity Air Pollution Studies-Seoul (MAPS-Seoul) campaign (from May to June 2015) in South Korea, ground-based measurements based on the sun-photometer were conducted at the AERONET-registered sites. Using dataset obtained from five local stations (Anmyon, Gangneung_WNU, Gosan_SNU, Hankuk_UFS, and Yonsei_University), we try to classify the aerosol types based on multiple algorithms and compare results to evaluate the performance of each method. Generally, the classification method utilizes the single scattering albedo (SSA), providing the information of radiative absorptivity. Since the SSA is only available when the air turbidity is high enough, type classification using SSA only reflects the high polluted case . On the other hand, there are some classification methods not using SSA, capable to capture the aerosol type in less polluted conditions. Thus, we need to consider simultaneously different classification features obtained from the inter-comparison of multiple methods for better understanding of regionally dominant aerosol type. Our analysis during the MAPS-Seoul campaign reveals the high radiative absorption at Hankuk_UFS, but high non-absorbing properties at Gosan_SNU. Back-trajectory analyses are also conducted to examine how the pattern of air-mass transport relates to the regional aerosol types. The result indicates the high domestic contribution to the Seoul metropolitan area, but relatively high contribution of Chinese pollutants to the western coast in the Korean peninsula, such as Anmyon and Gosan_SNU. Additional investigation should be more performed to generalize or improve findings in this study.