Pre-industrial to end 21st century projections of tropospheric ozone from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP) 1Cooperative Institute for Research in the Environmental Sciences, University of Colorado-Boulder, Boulder, Colorado, USA 2Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado, USA 3Centre for Atmospheric Science, University of Cambridge, UK 4National Centre for Atmospheric Science, University of Cambridge, UK 5NASA Jet Propulsion Laboratory, Pasadena, California, USA 6National Center for Atmospheric Research, Boulder, Colorado, USA 7UCAR/NOAA Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey, USA 8School of GeoSciences, University of Edinburgh, Edinburgh, UK 9Department of Physics, Imperial College, London, UK 10Lancaster Environment Centre, University of Lancaster, Lancaster, UK 11Lawrence Livermore National Laboratory, Livermore, California, USA 12Agenzia nazionale per le nuove tecnologie, l'energia e lo sviluppo economico sostenibile (ENEA), Bologna, Italy 13Met Office Hadley Centre, Exeter, UK 14CICERO, Center for International Climate and Environmental Research-Oslo, Oslo, Norway 15Deutsches Zentrum für Luft- und Raumfahrt (DLR), Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany 16NASA Goddard Institute for Space Studies, and Columbia Earth Institute, Columbia University, New York City, New York, USA 17NOAA Geophysical Fluid Dynamics Laboratory, Princeton, New Jersey, USA 18GAME/CNRM, Météo-France, CNRS – Centre National de Recherches Météorologiques, Toulouse, France 19Frontier Research Center for Global Change, Japan Marine Science and Technology Center, Yokohama, Japan 20Canadian Centre for Climate Modeling and Analysis, Environment Canada, Victoria, British Columbia, Canada 21NASA Goddard Space Flight Center, Greenbelt, Maryland, USA 22Universities Space Research Association, Columbia, Maryland, USA 23Department of Earth and Environmental Science, Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan 24Laboratoire des Sciences du Climat et de l'Environnement, LSCE-CEA-CNRS-UVSQ, Gif-sur-Yvette, France 25National Institute of Water and Atmospheric Research, Lauder, New Zealand Abstract. Present day tropospheric ozone and its changes between 1850 and 2100 are considered, analysing 15 global models that participated in the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP). The multi-model mean compares well against present day observations. The seasonal cycle correlates well, except for some locations in the tropical upper troposphere. Most (75%) of the models are encompassed with a range of global mean tropospheric ozone column estimates from satellite data, although there is a suggestion of a high bias in the Northern Hemisphere and a low bias in the Southern Hemisphere. Compared to the present day multi-model mean tropospheric ozone burden of 337 Tg, the multi-model mean burden for 1850 time slice is ~ 30% lower. Future changes were modelled using emissions and climate projections from four Representative Concentration Pathways (RCPs). Compared to 2000, the relative changes for the tropospheric ozone burden in 2030 (2100) for the different RCPs are: −5% (−22%) for RCP2.6, 3% (−8%) for RCP4.5, 0% (−9%) for RCP6.0, and 5% (15%) for RCP8.5. Model agreement on the magnitude of the change is greatest for larger changes. Reductions in precursor emissions are common across the RCPs and drive ozone decreases in all but RCP8.5, where doubled methane and a larger stratospheric influx increase ozone. Models with high ozone abundances for the present day also have high ozone levels for the other time slices, but there are no models consistently predicting large or small changes. Spatial patterns of ozone changes are well correlated across most models, but are notably different for models without time evolving stratospheric ozone concentrations. A unified approach to ozone budget specifications is recommended to help future studies attribute ozone changes and inter-model differences more clearly. Citation: Young, P. J., Archibald, A. T., Bowman, K. W., Lamarque, J.-F., Naik, V., Stevenson, D. S., Tilmes, S., Voulgarakis, A., Wild, O., Bergmann, D., Cameron-Smith, P., Cionni, I., Collins, W. J., Dalsøren, S. B., Doherty, R. M., Eyring, V., Faluvegi, G., Horowitz, L. W., Josse, B., Lee, Y. H., MacKenzie, I. A., Nagashima, T., Plummer, D. A., Righi, M., Rumbold, S. T., Skeie, R. B., Shindell, D. T., Strode, S. A., Sudo, K., Szopa, S., and Zeng, G.: Pre-industrial to end 21st century projections of tropospheric ozone from the Atmospheric Chemistry and Climate Model Intercomparison Project (ACCMIP), Atmos. Chem. Phys. Discuss., 12, 21615-21677, doi:10.5194/acpd-12-21615-2012, 2012. |
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