Global Tropospheric Ozone Responses to Reduced NOₓ Emissions Linked to the COVID-19 Worldwide Lockdowns
Abstract
Efforts to stem the transmission of coronavirus disease 2019 (COVID-19) led to rapid, global ancillary reductions in air pollutant emissions. Here, we quantify the impact on tropospheric ozone using a multiconstituent chemical data assimilation system. Anthropogenic NOGlobal Tropospheric Ozone Responses to Reduced Noₓ Emissions Linked to the COVID-19 Worldwide Lockdowns emissions dropped by at least 15% globally and 18 to 25% regionally in April and May 2020, which decreased free tropospheric ozone by up to 5 parts per billion, consistent with independent satellite observations. The global total tropospheric ozone burden declined by 6TgO₃ (∼2%) in May and June 2020, largely due to emission reductions in Asia and the Americas that were amplified by regionally high ozone production efficiencies (up to 4 TgO₃/TgN). Our results show that COVID-19 mitigation left a global atmospheric imprint that altered atmospheric oxidative capacity and climate radiative forcing, providing a test of the efficacy of NOₓ emissions controls for co-benefiting air quality and climate.
Additional Information
© 2021 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution License 4.0 (CC BY). Submitted 17 November 2020. Accepted 21 April 2021. Published 9 June 2021. We acknowledge the use of data products from the National Aeronautics and Space Administration (NASA) Aura and EOS Terra and Aqua satellite missions. We also acknowledge the free use of the tropospheric NO₂ column data from the SCIAMACHY, GOME-2, and OMI sensors from www.qa4ecv.eu and from TROPOMI. The OpenAQ surface ozone data were obtained through EPA and the World Air Quality Index Project. The TROPOMI NO₂ algorithm and data processors have been developed by KNMI under the NSO TROPOMI Science Contract, in cooperation with ESA. Sentinel-5 Precursor is an ESA mission on behalf of the European Commission (EC). The Earth Simulator was used for model simulations with support of the Japan Agency for Marine-Earth Science and Technology. Part of this work was conducted at the Jet Propulsion Laboratory, California Institute of Technology, under contract with the NASA. K.M. and K.B. acknowledge the support of the NASA Atmospheric Composition: Aura Science Team Program (19-AURAST19-0044) and the TROPESS project. Author contributions: K.M., K.B., and J.L.N. designed the research; all the authors performed research and wrote and edited the paper. Competing interests: The authors declare that they have no competing interests. Data and materials availability: All data needed to evaluate the conclusions in the paper are present in the paper and/or the Supplementary Materials. The basic concentration and emission data used in the study can be downloaded freely from https://tes.jpl.nasa.gov/chemical-reanalysis/.Attached Files
Published - sciadv.abf7460.pdf
Supplemental Material - abf7460_data_file_s1.xlsx
Supplemental Material - abf7460_sm.pdf
Supplemental Material - sciadv.abf7460_data_file_s1.zip
Files
Additional details
- Alternative title
- Global Tropospheric Ozone Responses to Reduced NOx Emissions Linked to the COVID-19 Worldwide Lockdowns
- PMCID
- PMC8189586
- Eprint ID
- 111883
- Resolver ID
- CaltechAUTHORS:20211116-003049409
- NASA/JPL/Caltech
- Created
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2021-11-16Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field
- Caltech groups
- Keck Institute for Space Studies, COVID-19