Did the COVID-19 Crisis Reduce Free Tropospheric Ozone across the Northern Hemisphere?

• Main Authors: Steinbrecht, Wolfgang, Kubistin, Dagmar, Plass-Dülmer, Christian, Davies, Jonathan, Tarasick, David W., Gathen, Peter von der, Deckelmann, Holger, Jepsen, Nis, Kivi, Rigel, Lyall, Norrie, Palm, Mathias, Notholt, Justus, Kois, Bogumil, Oelsner, Peter, Allaart, Marc, Piters, Ankie, Gill, Michael, Malderen, Roeland Van, Delcloo, Andy, Sussmann, Ralf, Mahieu, Emmanuel, Servais, christian, Romanens, Gonzague, Stübi, René, Ancellet, Gérard, Godin-Beekmann, Sophie, Yamanouchi, Shoma, Strong, Kimberly, Johnson, Bryan J. J., Cullis, Patrick, Petropavlovskikh, Irina, Hannigan, James W., Hernandez, Jose-Luis, Rodriguez, Ana Diaz, Nakano, Tatsumi, Chouza, Fernando, Leblanc, Thierry, Torres, Carlos, Garcìa, Omaira, Röhling, Amelie, Schneider, Matthias, Blumenstock, Thomas, Tully, Matt, Paton-Walsh, Clare, Jones, Nicholas Brian, Querel, Richard, Strahan, Susan E., Stauffer, Ryan Michael, Thompson, Anne M., Inness, Antje
• Other Authors: Deutscher Wetterdienst Offenbach (DWD), Environment and Climate Change Canada, Alfred Wegener Institute for Polar and Marine Research (AWI), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Danish Meteorological Institute (DMI), Finnish Meteorological Institute (FMI), Met Office Lerwick, University of Bremen, Institute of Meteorology and Water Management - National Research Institute (IMGW - PIB), Royal Netherlands Meteorological Institute (KNMI), Irish Meteorological Service (MET ÉIREANN), Institut Royal Météorologique de Belgique Bruxelles (IRM), Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU), Karlsruher Institut für Technologie (KIT), Institut d'Astrophysique et de Géophysique Liège, Université de Liège, Federal Office of Meteorology and Climatology MeteoSwiss, TROPO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), STRATO - LATMOS, Department of Physics Toronto, University of Toronto, NOAA Earth System Research Laboratory (ESRL), National Oceanic and Atmospheric Administration (NOAA), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado Boulder -National Oceanic and Atmospheric Administration (NOAA), National Center for Atmospheric Research Boulder (NCAR), Agencia Estatal de Meteorología (AEMet), Meteorological Research Institute Tsukuba (MRI), Japan Meteorological Agency (JMA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Izaña Atmospheric Research Center (IARC), Institut für Meteorologie und Klimaforschung - Atmosphärische Spurengase und Fernerkundung (IMK-ASF), Australian Bureau of Meteorology Melbourne (BoM), Australian Government, School of Chemistry Wollongong, University of Wollongong, National Institute of Water and Atmospheric Research Lauder (NIWA), NASA Goddard Space Flight Center (GSFC), Universities Space Research Association (USRA), European Centre for Medium-Range Weather Forecasts (ECMWF), NOAA Chemical Sciences Laboratory (CSL)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2021
• Subjects: Ozone; Troposphere; Emissions; COVID-19; [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; [SDV]Life Sciences [q-bio]; Arctic
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03130203; https://hal-insu.archives-ouvertes.fr/insu-03130203v3/document; https://hal-insu.archives-ouvertes.fr/insu-03130203v3/file/895994_2_merged_1611841504.pdf

International audience Throughout spring and summer 2020, ozone stations in the northern extratropics recorded unusually low ozone in the free troposphere. From April to August, and from 1 to 8 kilometers altitude, ozone was on average 7% (≈4 nmol/mol) below the 2000 to 2020 climatological mean. Such low ozone, over several months, and at so many stations, has not been observed in any previous year since at least 2000. Atmospheric composition analyses from the Copernicus Atmosphere Monitoring Service and simulations from the NASA GMI model indicate that the large 2020 springtime ozone depletion in the Arctic stratosphere contributed less than one quarter of the observed tropospheric anomaly. The observed anomaly is consistent with recent chemistry-climate model simulations, which assume emissions reductions similar to those caused by the COVID-19 crisis. COVID-19 related emissions reductions appear to be the major cause for the observed reduced free tropospheric ozone in 2020.