Uncertainties in recent tropical stratospheric and tropospheric ozone changes limit the use of observational constraints for assessing future ozone change
Year: 2026
Type: article
Abstract: A variety of chemical and dynamical processes in the troposphere and stratosphere affect tropical total column ozone (TCO), the net effect of which may cause changes in surface UV radiation and impact human and ecosystem health. We use dynamical linear modeling to estimate changes in tropical TCO and partial column ozone (PCO) in the troposphere and three stratospheric layers to assess agreement between satellite composites and chemistry-climate model simulations from two multi-model experiments (CCMI-1 and CCMI-2022). While both model experiments show tropical TCO increases over 2000–2021, multimodel-mean CCMI-2022 changes (+2.5 DU) agree slightly better with observations (+3.3 DU) than CCMI-1 (+1.6 DU). However, this overall agreement obscures multiple systematic differences in PCO changes between the models and observations across atmospheric layers. For example, since 2000 tropical tropospheric PCO increased significantly in CCMI-2022 (+1.5 DU) but not in CCMI-1 (+0.3 DU), largely explaining the difference in TCO changes. Also, despite nearly identical stratospheric PCO changes, CCMI-2022 changes are slightly more negative than CCMI-1 in the lower stratosphere (by ∼ 0.5 DU) and more positive in the middle/upper stratosphere. Crucially, substantial differences exist between observational PCO changes, particularly in the troposphere and middle/upper stratosphere, and these disagreements limit the ability to evaluate CCM fidelity for past changes. While early and late century trends are correlated across models, suggesting a potential emergent constraint on ozone, the spread in observational trends means they are unable to provide guidance on the credibility of model projections for a given emissions scenario.
Authors: Sean M. Davis, William T. Ball, Yue Jia, Gabriel Chiodo, Justin A. Alsing, James Keeble, Hideharu Akiyoshi, Carlo Arosio, Ewa M. Bednarz, Andreas Chrysanthou, Melanie Coldewey-Egbers, Robert Damadeo, Sandip Dhomse, Mohamadou A. Diallo, Simone Dietmuller, Roland Eichinger, Stacey Frith, Birgit Hassler, Michaela I. Hegglin, Daan Hubert, Patrick Jöckel, Béatrice Josse, Natalya Kramarova, Diego Loyola, Eliane Maillard Barras, Marion Marchand, Olaf Morgenstern, David Plummer, Robert W. Portmann, Karen H. Rosenlof, Alexei Rozanov, Viktoria F. Sofieva, Johannes Staehelin, Timofei Sukhodolov, Kleareti Tourpali, Ronald J. Van der A, H. J. Ray Wang, Krzysztof Wargan, Shingo Watanabe, Mark Weber, Jeannette D. Wild, Yousuke Yamashita, Jerry Ziemke
Institutions: NOAA Chemical Sciences Laboratory, Royal Netherlands Meteorological Institute, Delft University of Technology, The University of Texas at Dallas, Consejo Superior de Investigaciones Científicas, Instituto de Geociencias, Stockholm University, Lancaster University, National Institute for Environmental Studies, University of Bremen, Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, University of Leeds, Aristotle University of Thessaloniki, Deutsches Zentrum für Luft- und Raumfahrt e. V. (DLR), Langley Research Center, National Centre for Earth Observation, Forschungszentrum Jülich, Charles University, Goddard Space Flight Center, Adnet Systems (United States), University of Wuppertal, University of Reading, Royal Belgian Institute for Space Aeronomy, Centre National de la Recherche Scientifique, Centre National de Recherches Météorologiques, Météo-France, Université de Toulouse, Federal Office of Meteorology and Climatology MeteoSwiss, Université de Versailles Saint-Quentin-en-Yvelines, Sorbonne Université, Institut Pierre-Simon Laplace, Laboratoire atmosphères, milieux, observations spatiales, Deutscher Wetterdienst, University of Canterbury, National Institute of Water and Atmospheric Research, Environment and Climate Change Canada, Finnish Meteorological Institute, ETH Zurich, Institute for Atmospheric and Climate Science, Physikalisch-Meteorologisches Observatorium Davos, Georgia Institute of Technology, Science Systems and Applications (United States), Japan Agency for Marine-Earth Science and Technology, Tohoku University, Advanced Institute for Marine Ecosystem Change, National Oceanic and Atmospheric Administration, NOAA National Environmental Satellite Data and Information Service, NOAA Center for Satellite Applications and Research, Earth System Science Interdisciplinary Center, University of Maryland, College Park, Morgan State University
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $1,725
Funders: National Aeronautics and Space Administration, European Space Agency, Ministry of Education, Culture, Sports, Science and Technology, Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung, Belgian Federal Science Policy Office, Deutsches Zentrum für Luft- und Raumfahrt, National Oceanic and Atmospheric Administration, European Research Council, Japan Society for the Promotion of Science
Awards: G231529095, A study of the effects of energetic particle precipitation on the terrestrial environment based on models and observations in the northern and southern auroral belts, Assessing global aerosol variations and their impacts on climate change using multi-constituent satellite observations and mulit-model analysis, フンガ・トンガ＝フンガ・ハアパイ海底火山噴火の気候とオゾン層へのインパクト, G7198630863, G7792052577, G7970554450, Clarification of interaction processes between the stratospheric circulation and ozone changes, G8091993380, G9000848644, G9000848823, G9000849214, G9000849391, G9000849466
OpenAlex ID: W7216117063