The first preliminary SO2 result over East Asia from GEMS

Abstract:

Nitrogen oxides (NO_x) is predominantly emitted from fossil fuel combustion and is an important precursor for tropospheric ozone and fine particulate matter. It is imperative to accurately estimate NO_x emissions to understand and predict ambient air quality and establish pollution control policies. However, current NO_x emission estimates are often quite uncertain and do not reflect the variations of vehicular traffic in daily urban activity. Conventionally, polar-orbiting satellites have provided NO₂ column data once per day. In contrast, GEMS on a geostationary orbit observes the atmospheric trace gas and aerosol concentrations on an hourly basis. In this study, we utilize NO₂ column data from the first GEMS measurements to derive hourly NO_x emissions in Seoul. The newly estimated NO_x emissions will be compared with typical diurnal profiles in the bottom-up emission inventory. Validation strategies regarding the improvement of NO₂ retrieval quality such as air mass factor will also be discussed.