A research product for tropospheric NO2 columns from Geostationary Environment Monitoring Spectrometer based on Peking University OMI NO2 algorithm

• DOI: 10.5194/amt-16-4643-2023
• Publication Date: 2023-10-12T09:56:53Z
• Authors: Yuhang Zhang; Jintai Lin; Jhoon Kim; Hanlim Lee; Junsung Park; Hyunkee Hong; Michel Van Roozen...; Francois Hendrick; Ting Wang; Pucai Wang; Qin He; Kai Qin; Yongjoo Choi; Yugo Kanaya; Jin Xu; Pinhua Xie; Xin Tian; Sanbao Zhang; Shanshan Wang; Siyang Cheng; Xinghong Cheng; Jianzhong Ma; Thomas Wagner; Robert Spurr; Lulu Chen; Hao Kong; Mengyao Liu
• Keywords: Ozone Monitoring Instrument; Tropospheric ozone; Nadir

Abstract. Tropospheric vertical column densities (VCDs) of nitrogen dioxide (NO2) retrieved from sun-synchronous satellite instruments have provided abundant NO2 data for environmental studies, but such are limited by retrieval uncertainties and insufficient temporal sampling (e.g., once a day). The Geostationary Environment Monitoring Spectrometer (GEMS) launched in February 2020 monitors at an unprecedented hourly resolution during the daytime. Here we present research product tropospheric VCDs, referred to as POMINO–GEMS (where POMINO is Peking University OMI algorithm). We develop hybrid method combining GEMS, TROPOMI (TROPOspheric Instrument) GEOS-CF (Global Earth Observing System Composition Forecast) generate slant (SCDs). then derive air mass factors (AMFs) with explicit corrections surface reflectance anisotropy aerosol optical effects through parallelized pixel-by-pixel radiative transfer calculations. Prerequisite cloud parameters O2–O2 algorithm using ancillary consistent those used AMF initial VCDs June–August 2021 exhibits strong hotspot signals over megacities distinctive diurnal variations polluted clean areas. agree POMINO–TROPOMI v1.2.2 (R=0.98; NMB = 4.9 %) East Asia, slight differences associated viewing geometries properties affecting retrieval. also shows good agreement following: OMNO2 (Ozone Instrument (OMI) Standard Product) v4 (R=0.87; −16.8 %); GOME-2 Ozone Experiment-2) GDP (GOME Data Processor) 4.8 (R=0.83; −1.5 products. small biases against ground-based MAX-DOAS (multi-axis differential absorption spectroscopy) VCD nine sites (NMB −11.1 %), modest or high correlation variation six urban suburban (R 0.60 0.96). spatiotemporal correlates well mobile car measurements Three Rivers source region on Tibetan Plateau (R=0.81). Surface concentrations estimated Ministry Ecology China (R=0.78; −26.3 all, urban, rural (R≥0.96). will be made freely available users study variations, sources impacts NO2.