A005-0005
Global Changes in Formaldehyde (HCHO) Columns Observed from Space during the Early Stage of the COVID-19 Pandemic

Monday, 7 December 2020
Poster
Wenfu Sun1, Lei Zhu1, Dongchuan Pu1, Yuyang Chen1, Tzung-May Fu1, Xiaofei Wang2, Xin Yang1 and Isabelle De Smedt3, (1)Southern University of Science and Technology, School of Environmental Science and Engineering, Shenzhen, China, (2)Fudan University, Department of Environmental Science and Engineering, Shanghai, China, (3)Royal Belgian Institute for Space Aeronomy, Brussels, Belgium
Abstract:
Satellite HCHO data are widely used as a reliable proxy of volatile organic compounds (VOCs) to constrain underlying emissions and chemistry. Here we examine global changes in HCHO columns during the early stage of the COVID-19 pandemic with observations from the Tropospheric Monitoring Instrument (TROPOMI). After correcting for the impact of temperature variations on HCHO, we find significant HCHO declines over the Northern China Plain (-11.0%), driven by a sudden reduction in both anthropogenic nitrogen oxides (NOx; -36.0%) and non-methane VOC (MNVOC; -10.0% to -15.0%) emissions during the massive lockdown in China from January to April 2020. Meanwhile, HCHO columns change significantly over the Southeastern Asia (-11.2% to +15.1%), Central Africa (-8.2% to +7.6%), Central America (-10% to +18.6%), and Australia (-8.9% to +17.8%), consistent with fire activities. Our work also points to changes related to other meteorological factors over India, South Africa, and South America, as well as the likely retrieval interference from dust over the middle latitudes.
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