Trends in Columnar Aerosol Properties from SKYNET Downwind of Seoul During the Last Decade

A skyradiometer (Prede POM-02) has been operated to investigate aerosol properties at a SKYNET (SKYradiometer NETwork) YGN (Yongin) site for 11 years, starting from April 2007. The site is located at the rooftop of a five-story building on the hill (37.34 °N, 127.27 °E, 167 m above sea level), about 35 km southeast of the center of Seoul, downwind of urban pollution in the prevailing westerlies. POM-02 measures diffuse radiation at 6-min interval. Using skyrad.pack version 5, aerosol optical and microphysical properties at wavelengths of 400, 500, 675, 870 and 1020 nm were retrieved. Temporal variations in columnar properties including aerosol optical depth (AOD), fine mode volume fraction (FMVF), single-scattering albedo (SSA), and absorption Ångström exponent (AAE), and the relationship between them were examined to track the air quality over the Seoul metropolitan area during the last decade. The potential source areas for high aerosol properties were identified using the potential source contribution function (PSCF) analysis.