Estimates of ozone return dates from Chemistry-Climate Model Initiative simulations

International audience We analyse simulations performed for the Chemistry-Climate Model Initiative (CCMI) to estimate the return dates of the stratospheric ozone layer from depletion caused by anthropogenic stratospheric chlorine and bromine. We consider a total of 155 simulations from 20 models, in...

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Published in:Atmospheric Chemistry and Physics
Main Authors: Dhomse, Sandip, Kinnison, Douglas, Chipperfield, Martyn P., Cionni, Irene, Hegglin, Michaela, Abraham, N. Luke, Akiyoshi, Hideharu, Archibald, Alex T., Bednarz, Ewa M., Bekki, Slimane, Braesicke, Peter, Butchart, Neal, Dameris, Martin, Deushi, Makoto, Frith, Stacy, Hardiman, Steven C., Hassler, Birgit, Horowitz, Larry W., Hu, Rong Ming, Jöckel, Patrick, Josse, Béatrice, Kirner, Oliver, Kremser, Stefanie, Langematz, Ulrike, Lewis, Jared, Marchand, Marion, Lin, Meiyun, Mancini, Eva, Marecal, Virginie, Michou, Martine, Morgenstern, Olaf, O'Connor, Fiona M., Oman, Luke, Pitari, Giovanni, Plummer, David A., Pyle, John A., Revell, Laura E., Rozanov, Eugene, Schofield, Robyn, Stenke, Andrea, Stone, Kane, Sudo, Kengo, Tilmes, Simone, Visioni, Daniele, Yamashita, Yousuke, Zeng, Guang
Other Authors: School of Earth and Environment Leeds (SEE), University of Leeds, National Center for Atmospheric Research Boulder (NCAR), Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Department of Meteorology Reading, University of Reading (UOR), Department of Chemistry Cambridge, UK, University of Cambridge UK (CAM), National Centre for Atmospheric Science Leeds (NCAS), Natural Environment Research Council (NERC), National Institute for Environmental Studies (NIES), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut für Meteorologie und Klimaforschung - Atmosphärische Spurengase und Fernerkundung (IMK-ASF), Karlsruher Institut für Technologie (KIT), Met Office Hadley Centre (MOHC), United Kingdom Met Office Exeter, DLR Institut für Physik der Atmosphäre = DLR Institute of Atmospheric Physics (IPA), Deutsches Zentrum für Luft- und Raumfahrt Oberpfaffenhofen-Wessling (DLR), Meteorological Research Institute Tsukuba (MRI), Japan Meteorological Agency (JMA), NASA Goddard Space Flight Center (GSFC), NOAA Geophysical Fluid Dynamics Laboratory (GFDL), National Oceanic and Atmospheric Administration (NOAA), Centre national de recherches météorologiques (CNRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS), Steinbuch Centre for Computing Karlsruhe (SCC), Institut für Meteorologie Berlin, Freie Universität Berlin, Bodeker Scientific, Atmospheric and Oceanic Sciences Program Princeton (AOS Program), National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA)-Princeton University, Department of Physical and Chemical Sciences L'Aquila (DSFC), Università degli Studi dell'Aquila = University of L'Aquila (UNIVAQ), Centre of Excellence CETEMPS, National Institute of Water and Atmospheric Research Lauder (NIWA), Canadian Centre for Climate Modelling and Analysis (CCCma), Environment and Climate Change Canada (ECCC), Centre for Atmospheric Science Cambridge, UK, Institute for Atmospheric and Climate Science Zürich (IAC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC), ARC Centre of Excellence for Climate System Science, University of New South Wales Sydney (UNSW)-Australian Research Council Canberra (ARC), School of Earth Sciences Melbourne, Faculty of Science Melbourne
Format: Article in Journal/Newspaper
Language:English
Published: HAL CCSD 2018
Subjects:
Online Access:https://insu.hal.science/insu-01702481
https://insu.hal.science/insu-01702481/document
https://insu.hal.science/insu-01702481/file/acp-18-8409-2018.pdf
https://doi.org/10.5194/acp-18-8409-2018
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institution Open Polar
collection Institut national des sciences de l'Univers: HAL-INSU
op_collection_id ftinsu
language English
topic [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean
Atmosphere
spellingShingle [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean
Atmosphere
Dhomse, Sandip
Kinnison, Douglas
Chipperfield, Martyn P.
Cionni, Irene
Hegglin, Michaela
Abraham, N. Luke
Akiyoshi, Hideharu
Archibald, Alex T.
Bednarz, Ewa M.
Bekki, Slimane
Braesicke, Peter
Butchart, Neal
Dameris, Martin
Deushi, Makoto
Frith, Stacy
Hardiman, Steven C.
Hassler, Birgit
Horowitz, Larry W.
Hu, Rong Ming
Jöckel, Patrick
Josse, Béatrice
Kirner, Oliver
Kremser, Stefanie
Langematz, Ulrike
Lewis, Jared
Marchand, Marion
Lin, Meiyun
Mancini, Eva
Marecal, Virginie
Michou, Martine
Morgenstern, Olaf
O'Connor, Fiona M.
Oman, Luke
Pitari, Giovanni
Plummer, David A.
Pyle, John A.
Revell, Laura E.
Rozanov, Eugene
Schofield, Robyn
Stenke, Andrea
Stone, Kane
Sudo, Kengo
Tilmes, Simone
Visioni, Daniele
Yamashita, Yousuke
Zeng, Guang
Estimates of ozone return dates from Chemistry-Climate Model Initiative simulations
topic_facet [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]
[SDU.OCEAN]Sciences of the Universe [physics]/Ocean
Atmosphere
description International audience We analyse simulations performed for the Chemistry-Climate Model Initiative (CCMI) to estimate the return dates of the stratospheric ozone layer from depletion caused by anthropogenic stratospheric chlorine and bromine. We consider a total of 155 simulations from 20 models, including a range of sensitivity studies which examine the impact of climate change on ozone recovery. For the control simulations (unconstrained by nudging towards analysed meteorology) there is a large spread (±20 DU in the global average) in the predictions of the absolute ozone column. Therefore, the model results need to be adjusted for biases against historical data. Also, the interannual variability in the model results need to be smoothed in order to provide a reasonably narrow estimate of the range of ozone return dates. Consistent with previous studies, but here for a Representative Concentration Pathway (RCP) of 6.0, these new CCMI simulations project that global total column ozone will return to 1980 values in 2047 (with a 1-σ uncertainty of 2042–2052). At Southern Hemisphere mid-latitudes column ozone is projected to return to 1980 values in 2046 (2042–2050), and at Northern Hemisphere mid-latitudes in 2034 (2024–2044). In the polar regions, the return dates are 2062 (2055–2066) in the Antarctic in October and 2035 (2025–2040) in the Arctic in March. The earlier return dates in the NH reflect the larger sensitivity to dynamical changes. Our estimates of return dates are later than those presented in the 2014 Ozone Assessment by approximately 5–15 years, depending on the region. In the tropics only around half the models predict a return to 1980 values, at around 2040, while the other half do not reach this value. All models show a negative trend in tropical total column ozone towards the end of the 21st century. The CCMI models generally agree in their simulation of the time evolution of stratospheric chlorine, which is the main driver of ozone loss and recovery. However, there are a few outliers which ...
author2 School of Earth and Environment Leeds (SEE)
University of Leeds
National Center for Atmospheric Research Boulder (NCAR)
Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA)
Department of Meteorology Reading
University of Reading (UOR)
Department of Chemistry Cambridge, UK
University of Cambridge UK (CAM)
National Centre for Atmospheric Science Leeds (NCAS)
Natural Environment Research Council (NERC)
National Institute for Environmental Studies (NIES)
STRATO - LATMOS
Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS)
Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)
Institut für Meteorologie und Klimaforschung - Atmosphärische Spurengase und Fernerkundung (IMK-ASF)
Karlsruher Institut für Technologie (KIT)
Met Office Hadley Centre (MOHC)
United Kingdom Met Office Exeter
DLR Institut für Physik der Atmosphäre = DLR Institute of Atmospheric Physics (IPA)
Deutsches Zentrum für Luft- und Raumfahrt Oberpfaffenhofen-Wessling (DLR)
Meteorological Research Institute Tsukuba (MRI)
Japan Meteorological Agency (JMA)
NASA Goddard Space Flight Center (GSFC)
NOAA Geophysical Fluid Dynamics Laboratory (GFDL)
National Oceanic and Atmospheric Administration (NOAA)
Centre national de recherches météorologiques (CNRM)
Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP)
Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3)
Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3)
Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS)
Steinbuch Centre for Computing Karlsruhe (SCC)
Institut für Meteorologie Berlin
Freie Universität Berlin
Bodeker Scientific
Atmospheric and Oceanic Sciences Program Princeton (AOS Program)
National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA)-Princeton University
Department of Physical and Chemical Sciences L'Aquila (DSFC)
Università degli Studi dell'Aquila = University of L'Aquila (UNIVAQ)
Centre of Excellence CETEMPS
National Institute of Water and Atmospheric Research Lauder (NIWA)
Canadian Centre for Climate Modelling and Analysis (CCCma)
Environment and Climate Change Canada (ECCC)
Centre for Atmospheric Science Cambridge, UK
Institute for Atmospheric and Climate Science Zürich (IAC)
Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich)
Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC)
ARC Centre of Excellence for Climate System Science
University of New South Wales Sydney (UNSW)-Australian Research Council Canberra (ARC)
School of Earth Sciences Melbourne
Faculty of Science Melbourne
format Article in Journal/Newspaper
author Dhomse, Sandip
Kinnison, Douglas
Chipperfield, Martyn P.
Cionni, Irene
Hegglin, Michaela
Abraham, N. Luke
Akiyoshi, Hideharu
Archibald, Alex T.
Bednarz, Ewa M.
Bekki, Slimane
Braesicke, Peter
Butchart, Neal
Dameris, Martin
Deushi, Makoto
Frith, Stacy
Hardiman, Steven C.
Hassler, Birgit
Horowitz, Larry W.
Hu, Rong Ming
Jöckel, Patrick
Josse, Béatrice
Kirner, Oliver
Kremser, Stefanie
Langematz, Ulrike
Lewis, Jared
Marchand, Marion
Lin, Meiyun
Mancini, Eva
Marecal, Virginie
Michou, Martine
Morgenstern, Olaf
O'Connor, Fiona M.
Oman, Luke
Pitari, Giovanni
Plummer, David A.
Pyle, John A.
Revell, Laura E.
Rozanov, Eugene
Schofield, Robyn
Stenke, Andrea
Stone, Kane
Sudo, Kengo
Tilmes, Simone
Visioni, Daniele
Yamashita, Yousuke
Zeng, Guang
author_facet Dhomse, Sandip
Kinnison, Douglas
Chipperfield, Martyn P.
Cionni, Irene
Hegglin, Michaela
Abraham, N. Luke
Akiyoshi, Hideharu
Archibald, Alex T.
Bednarz, Ewa M.
Bekki, Slimane
Braesicke, Peter
Butchart, Neal
Dameris, Martin
Deushi, Makoto
Frith, Stacy
Hardiman, Steven C.
Hassler, Birgit
Horowitz, Larry W.
Hu, Rong Ming
Jöckel, Patrick
Josse, Béatrice
Kirner, Oliver
Kremser, Stefanie
Langematz, Ulrike
Lewis, Jared
Marchand, Marion
Lin, Meiyun
Mancini, Eva
Marecal, Virginie
Michou, Martine
Morgenstern, Olaf
O'Connor, Fiona M.
Oman, Luke
Pitari, Giovanni
Plummer, David A.
Pyle, John A.
Revell, Laura E.
Rozanov, Eugene
Schofield, Robyn
Stenke, Andrea
Stone, Kane
Sudo, Kengo
Tilmes, Simone
Visioni, Daniele
Yamashita, Yousuke
Zeng, Guang
author_sort Dhomse, Sandip
title Estimates of ozone return dates from Chemistry-Climate Model Initiative simulations
title_short Estimates of ozone return dates from Chemistry-Climate Model Initiative simulations
title_full Estimates of ozone return dates from Chemistry-Climate Model Initiative simulations
title_fullStr Estimates of ozone return dates from Chemistry-Climate Model Initiative simulations
title_full_unstemmed Estimates of ozone return dates from Chemistry-Climate Model Initiative simulations
title_sort estimates of ozone return dates from chemistry-climate model initiative simulations
publisher HAL CCSD
publishDate 2018
url https://insu.hal.science/insu-01702481
https://insu.hal.science/insu-01702481/document
https://insu.hal.science/insu-01702481/file/acp-18-8409-2018.pdf
https://doi.org/10.5194/acp-18-8409-2018
genre Antarc*
Antarctic
Arctic
Climate change
genre_facet Antarc*
Antarctic
Arctic
Climate change
op_source ISSN: 1680-7316
EISSN: 1680-7324
Atmospheric Chemistry and Physics
https://insu.hal.science/insu-01702481
Atmospheric Chemistry and Physics, 2018, 18 (11), pp.8409-8438. ⟨10.5194/acp-18-8409-2018⟩
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spelling ftinsu:oai:HAL:insu-01702481v1 2024-04-28T08:03:06+00:00 Estimates of ozone return dates from Chemistry-Climate Model Initiative simulations Dhomse, Sandip Kinnison, Douglas Chipperfield, Martyn P. Cionni, Irene Hegglin, Michaela Abraham, N. Luke Akiyoshi, Hideharu Archibald, Alex T. Bednarz, Ewa M. Bekki, Slimane Braesicke, Peter Butchart, Neal Dameris, Martin Deushi, Makoto Frith, Stacy Hardiman, Steven C. Hassler, Birgit Horowitz, Larry W. Hu, Rong Ming Jöckel, Patrick Josse, Béatrice Kirner, Oliver Kremser, Stefanie Langematz, Ulrike Lewis, Jared Marchand, Marion Lin, Meiyun Mancini, Eva Marecal, Virginie Michou, Martine Morgenstern, Olaf O'Connor, Fiona M. Oman, Luke Pitari, Giovanni Plummer, David A. Pyle, John A. Revell, Laura E. Rozanov, Eugene Schofield, Robyn Stenke, Andrea Stone, Kane Sudo, Kengo Tilmes, Simone Visioni, Daniele Yamashita, Yousuke Zeng, Guang School of Earth and Environment Leeds (SEE) University of Leeds National Center for Atmospheric Research Boulder (NCAR) Agenzia Nazionale per le nuove Tecnologie, l’energia e lo sviluppo economico sostenibile = Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA) Department of Meteorology Reading University of Reading (UOR) Department of Chemistry Cambridge, UK University of Cambridge UK (CAM) National Centre for Atmospheric Science Leeds (NCAS) Natural Environment Research Council (NERC) National Institute for Environmental Studies (NIES) STRATO - LATMOS Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS) Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS) Institut für Meteorologie und Klimaforschung - Atmosphärische Spurengase und Fernerkundung (IMK-ASF) Karlsruher Institut für Technologie (KIT) Met Office Hadley Centre (MOHC) United Kingdom Met Office Exeter DLR Institut für Physik der Atmosphäre = DLR Institute of Atmospheric Physics (IPA) Deutsches Zentrum für Luft- und Raumfahrt Oberpfaffenhofen-Wessling (DLR) Meteorological Research Institute Tsukuba (MRI) Japan Meteorological Agency (JMA) NASA Goddard Space Flight Center (GSFC) NOAA Geophysical Fluid Dynamics Laboratory (GFDL) National Oceanic and Atmospheric Administration (NOAA) Centre national de recherches météorologiques (CNRM) Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP) Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3) Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales Toulouse (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France-Centre National de la Recherche Scientifique (CNRS) Steinbuch Centre for Computing Karlsruhe (SCC) Institut für Meteorologie Berlin Freie Universität Berlin Bodeker Scientific Atmospheric and Oceanic Sciences Program Princeton (AOS Program) National Oceanic and Atmospheric Administration (NOAA)-National Oceanic and Atmospheric Administration (NOAA)-Princeton University Department of Physical and Chemical Sciences L'Aquila (DSFC) Università degli Studi dell'Aquila = University of L'Aquila (UNIVAQ) Centre of Excellence CETEMPS National Institute of Water and Atmospheric Research Lauder (NIWA) Canadian Centre for Climate Modelling and Analysis (CCCma) Environment and Climate Change Canada (ECCC) Centre for Atmospheric Science Cambridge, UK Institute for Atmospheric and Climate Science Zürich (IAC) Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich) Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC) ARC Centre of Excellence for Climate System Science University of New South Wales Sydney (UNSW)-Australian Research Council Canberra (ARC) School of Earth Sciences Melbourne Faculty of Science Melbourne 2018 https://insu.hal.science/insu-01702481 https://insu.hal.science/insu-01702481/document https://insu.hal.science/insu-01702481/file/acp-18-8409-2018.pdf https://doi.org/10.5194/acp-18-8409-2018 en eng HAL CCSD European Geosciences Union info:eu-repo/semantics/altIdentifier/doi/10.5194/acp-18-8409-2018 insu-01702481 https://insu.hal.science/insu-01702481 https://insu.hal.science/insu-01702481/document https://insu.hal.science/insu-01702481/file/acp-18-8409-2018.pdf doi:10.5194/acp-18-8409-2018 http://creativecommons.org/licenses/by/ info:eu-repo/semantics/OpenAccess ISSN: 1680-7316 EISSN: 1680-7324 Atmospheric Chemistry and Physics https://insu.hal.science/insu-01702481 Atmospheric Chemistry and Physics, 2018, 18 (11), pp.8409-8438. ⟨10.5194/acp-18-8409-2018⟩ [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph] [SDU.OCEAN]Sciences of the Universe [physics]/Ocean Atmosphere info:eu-repo/semantics/article Journal articles 2018 ftinsu https://doi.org/10.5194/acp-18-8409-2018 2024-04-05T00:40:08Z International audience We analyse simulations performed for the Chemistry-Climate Model Initiative (CCMI) to estimate the return dates of the stratospheric ozone layer from depletion caused by anthropogenic stratospheric chlorine and bromine. We consider a total of 155 simulations from 20 models, including a range of sensitivity studies which examine the impact of climate change on ozone recovery. For the control simulations (unconstrained by nudging towards analysed meteorology) there is a large spread (±20 DU in the global average) in the predictions of the absolute ozone column. Therefore, the model results need to be adjusted for biases against historical data. Also, the interannual variability in the model results need to be smoothed in order to provide a reasonably narrow estimate of the range of ozone return dates. Consistent with previous studies, but here for a Representative Concentration Pathway (RCP) of 6.0, these new CCMI simulations project that global total column ozone will return to 1980 values in 2047 (with a 1-σ uncertainty of 2042–2052). At Southern Hemisphere mid-latitudes column ozone is projected to return to 1980 values in 2046 (2042–2050), and at Northern Hemisphere mid-latitudes in 2034 (2024–2044). In the polar regions, the return dates are 2062 (2055–2066) in the Antarctic in October and 2035 (2025–2040) in the Arctic in March. The earlier return dates in the NH reflect the larger sensitivity to dynamical changes. Our estimates of return dates are later than those presented in the 2014 Ozone Assessment by approximately 5–15 years, depending on the region. In the tropics only around half the models predict a return to 1980 values, at around 2040, while the other half do not reach this value. All models show a negative trend in tropical total column ozone towards the end of the 21st century. The CCMI models generally agree in their simulation of the time evolution of stratospheric chlorine, which is the main driver of ozone loss and recovery. However, there are a few outliers which ... Article in Journal/Newspaper Antarc* Antarctic Arctic Climate change Institut national des sciences de l'Univers: HAL-INSU Atmospheric Chemistry and Physics 18 11 8409 8438