Evaluating stratospheric ozone and water vapour changes in CMIP6 models from 1850 to 2100

Atmospheric Chemistry and Physics Discussions

article

Keeble, James¹  Nowack, Peer³  Zeng, Guang⁵  Zhang, Jiankai⁶  Bodeker, Greg⁷  Burrows, Susannah⁹  Cameron-Smith, Philip^1,10  Cugnet, David^1,11  Danek, Christopher^1,12  Deushi, Makoto^1,13  Horowitz, Larry W.^1,14  Hassler, Birgit^1,15  Kubin, Anne^1,16  Li, Lijuan^1,17  Lohmann, Gerrit^1,12  Michou, Martine^1,18  Mills, Michael J.^1,19  Nabat, Pierre^1,18  Olivié, Dirk^2,20  Park, Sungsu^2,21  Seland, Øyvind^2,20  Stoll, Jens^1,16  Banerjee, Antara^2,22  Wieners, Karl-Hermann^2,24  Wu, Tongwen^2,25  Checa-Garcia, Ramiro^2,26  Chiodo, Gabriel^2,27  Davis, Sean^2,22  Eyring, Veronika^1,15  Griffiths, Paul T.¹  Morgenstern, Olaf⁵ 

[1] Department of Chemistry, University of Cambridge;National Centre for Atmospheric Science (NCAS), University of Cambridge;Grantham Institute, Department of Physics and the Data Science Institute, Imperial College London;Climatic Research Unit, School of Environmental Sciences, University of East Anglia;National Institute of Water and Atmospheric Research (NIWA);Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University;Bodeker Scientific;School of Geography, Environment and Earth Sciences, Victoria University of Wellington;Atmospheric Sciences & Global Change Division, Pacific Northwest National Laboratory;Earth and Energy Division, Lawrence Livermore National Laboratory;Laboratoire de Météorologie Dynamique, Institut Pierre-Simon Laplace, Sorbonne Université/CNRS / École Normale Supérieure – PSL Research University/École Polytechnique – IPP;Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Sciences;Meteorological Research Institute (MRI);GFDL/NOAA;Institut für Physik der Atmosphäre;Leibniz Institute for Tropospheric Research;State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences;Université de Toulouse;Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research;Norwegian Meteorological Institute;Seoul National University;NOAA Earth System Research Laboratory Chemical Sciences Division;Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado Boulder;Max Planck Institute for Meteorology;Beijing Climate Center, China Meteorological Administration;Laboratoire des sciences du climat et de l'environnement;Department of Environmental Systems Science, Swiss Federal Institute of Technology;Department of Applied Physics and Applied Math, Columbia University;University of Bremen, Institute of Environmental Physics (IUP)

DOI  :  10.5194/acp-21-5015-2021

学科分类：大气科学

来源: Copernicus Publications

【 摘 要 】

Stratospheric ozone and water vapour are key components of the Earth system, and past and future changes to both have important impacts on global and regional climate. Here, we evaluate long-term changes in these species from the pre-industrial period (1850) to the end of the 21st century in Coupled Model Intercomparison Project phase 6 (CMIP6) models under a range of future emissions scenarios. There is good agreement between the CMIP multi-model mean and observations for total column ozone (TCO), although there is substantial variation between the individual CMIP6 models. For the CMIP6 multi-model mean, global mean TCO has increased from ∼  300  DU in 1850 to ∼  305  DU in 1960, before rapidly declining in the 1970s and 1980s following the use and emission of halogenated ozone-depleting substances (ODSs). TCO is projected to return to 1960s values by the middle of the 21st century under the SSP2-4.5, SSP3-7.0, SSP4-3.4, SSP4-6.0, and SSP5-8.5 scenarios, and under the SSP3-7.0 and SSP5-8.5 scenarios TCO values are projected to be ∼  10  DU higher than the 1960s values by 2100. However, under the SSP1-1.9 and SSP1-1.6 scenarios, TCO is not projected to return to the 1960s values despite reductions in halogenated ODSs due to decreases in tropospheric ozone mixing ratios. This global pattern is similar to regional patterns, except in the tropics where TCO under most scenarios is not projected to return to 1960s values, either through reductions in tropospheric ozone under SSP1-1.9 and SSP1-2.6, or through reductions in lower stratospheric ozone resulting from an acceleration of the Brewer–Dobson circulation under other Shared Socioeconomic Pathways (SSPs). In contrast to TCO, there is poorer agreement between the CMIP6 multi-model mean and observed lower stratospheric water vapour mixing ratios, with the CMIP6 multi-model mean underestimating observed water vapour mixing ratios by ∼  0.5  ppmv at 70  hPa . CMIP6 multi-model mean stratospheric water vapour mixing ratios in the tropical lower stratosphere have increased by ∼  0.5  ppmv from the pre-industrial to the present-day period and are projected to increase further by the end of the 21st century. The largest increases ( ∼  2  ppmv ) are simulated under the future scenarios with the highest assumed forcing pathway (e.g. SSP5-8.5). Tropical lower stratospheric water vapour, and to a lesser extent TCO, shows large variations following explosive volcanic eruptions.

【 授权许可】

CC BY