Changes in SO2 Pollution Related to the Outbreak of the COVID-19 Pandemic Observed by Aura/OMI, SNPP/OMPS, and S5P/TROPOMI

Abstract:

The ongoing pandemic of coronavirus disease 2019 (COVID-19) has prompted sharp declines in gross domestic product (GDP) and industrial production worldwide, leading to significant reductions in the emissions of air pollutants. A number of recent studies have documented lower levels of nitrogen dioxide (NO₂), carbon monoxide, and aerosols observed in the first few months of 2020 that are atrritubed to government efforts to curb the spread of COVID-19. In this presentation, we will show that sulfur dioxide (SO₂) pollution has also experienced large changes in early 2020, using global observations from a trio of satellite sensors: Aura/Ozone Monitoring Instrument (OMI), Suomi NPP/Ozone Mapping and Profiler Suite (OMPS), and Sentinel-5P/TROPOspheric Monitoring Instrument (TROPOMI). With OMI and OMPS, we will focus on regions having relatively large SO₂ sources such as eastern China, India, the Middle East, and South Africa. To account for seasonal changes in SO₂, we will use long-term data records from these two sensors to establish a baseline time series of SO₂ levels for each region and compare it with the time series for 2020. We will also take advantage of the enhanced sensitivity to SO₂ afforded by high-resolution measurements from TROPOMI, to investigate changes over areas with relatively small SO₂ emissions such as the U.S. and Europe. In addition, the satellite observed changes in SO₂ will be compared with those in NO₂ to shed some light on the responses of different sectors (e.g., industry vs. transportation) to the pandemic. Finally, we will also discuss the top-down estimates of SO₂ emissions derived from satellite data for 2020 and for the previous years, to provide a quantitative assessment of the impacts of COVID-19 on SO₂ pollution.