Estimation of Anthropogenic Volatile Organic Compound Emissions in South Korea Using Formaldehyde Column Densities from Aircraft

Formaldehyde (HCHO) measurements from upcoming environmental geostationary satellites are expected to provide information about volatile organic compounds (VOCs) with finer temporal and spatial resolutions than those of current sun-synchronous satellites. The launch of Korean geostationary environmental satellite (GEMS) will occur in February 2020. Here we explore the application of GEMS observations as constrains for VOC emissions using HCHO column densities from aircraft platforms. The aircraft observations have fine temporal and spatial resolutions, although spatial and temporal coverages are limited. We use HCHO vertical column densities from the Geostationary Trace gas and Aerosol Sensor Optimization (GeoTASO) for KORUS-AQ campaign, which was an air quality field campaign held in South Korea. GeoTASO HCHO vertical columns in the afternoon are lower by -31% than those of ground-based Pandora instruments, but their spatial variability is consistent with that of model simulation and DC-8 aircraft. Total anthropogenic VOC (AVOC) emissions are estimated with HCHO yields and emission fractions for AVOC species as well as GeoTASO HCHO vertical columns over six source regions in South Korea, where there are traffics and industrial complexes including petrochemical plants. Estimated AVOC emissions are 1.2-2.8 times higher than those of the bottom-up inventory in five source regions except for Seoul Metropolitan Area, where AVOC emissions are estimated to be 33% lower than the bottom-up inventory. Also, we find AVOC emission factors for diurnal variations are too high in the model simulation.