No robust evidence of future changes in major stratospheric sudden warmings: a multi-model assessment from CCMI

• Published in: Atmospheric Chemistry and Physics
• Main Authors: Ayarzagüena, Blanca, Polvani, Lorenzo, Langematz, Ulrike, Akiyoshi, Hideharu, Bekki, Slimane, Butchart, Neal, Dameris, Martin, Deushi, Makoto, Hardiman, Steven, Jöckel, Patrick, Klekociuk, Andrew, Marchand, Marion, Michou, Martine, Morgenstern, Olaf, O'Connor, Fiona, Oman, Luke, Plummer, David, Revell, Laura, Rozanov, Eugene, Saint-Martin, David, Scinocca, John, Stenke, Andrea, Stone, Kane, Yamashita, Yousuke, Yoshida, Kohei, Zeng, Guang
• Other Authors: Departamento Fisica de la Tierra, Astronomía y Astrofísica Madrid, Universidad Complutense de Madrid = Complutense University of Madrid Madrid (UCM), Instituto de Geociencias Madrid (IGEO), Universidad Complutense de Madrid = Complutense University of Madrid Madrid (UCM)-Consejo Superior de Investigaciones Científicas Madrid (CSIC), Columbia University New York, Freie Universität Berlin, 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), Met Office Hadley Centre for Climate Change (MOHC), United Kingdom Met Office Exeter, DLR Institut für Physik der Atmosphäre (IPA), Deutsches Zentrum für Luft- und Raumfahrt Oberpfaffenhofen-Wessling (DLR), Meteorological Research Institute Tsukuba (MRI), Japan Meteorological Agency (JMA), Australian Antarctic Division (AAD), Australian Government, Department of the Environment and Energy, Antarctic Climate and Ecosystems Cooperative Research Centre (ACE-CRC), 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 Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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 Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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), National Institute of Water and Atmospheric Research Wellington (NIWA), NASA Goddard Space Flight Center (GSFC), Environment and Climate Change Canada, Institute for Atmospheric and Climate Science Zürich (IAC), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology Zürich (ETH Zürich), Bodeker Scientific, Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC), Canadian Centre for Climate Modelling and Analysis (CCCma), School of Earth Sciences Melbourne, Faculty of Science Melbourne, University of Melbourne-University of Melbourne, ARC Centre of Excellence for Climate System Science, University of New South Wales Sydney (UNSW)-Australian Research Council Canberra (ARC), Massachusetts Institute of Technology (MIT), Japan Agency for Marine-Earth Science and Technology (JAMSTEC)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: [PHYS.PHYS.PHYS-AO-PH]Physics [physics]/Physics [physics]/Atmospheric and Oceanic Physics [physics.ao-ph]; Arctic
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-01755048; https://hal-insu.archives-ouvertes.fr/insu-01755048/document; https://hal-insu.archives-ouvertes.fr/insu-01755048/file/acp-18-11277-2018.pdf; https://doi.org/10.5194/acp-18-11277-2018

International audience Major mid-winter stratospheric sudden warmings (SSWs) are the largest instance of wintertime variability in the Arctic stratosphere. Because SSWs are able to cause significant surface weather anomalies on intra-seasonal time scales, several previous studies have focused on their potential future change, as might be induced by anthropogenic forcings. However, a wide range of results have been reported, from a future increase in the frequency of SSWs to an actual decrease. Several factors might explain these contradictory results, notably the use of different metrics for the identification of SSWs, and the impact of large climatological biases in single-model studies. To bring some clarity, we here revisit the question of future SSWs changes, using an identical set of metrics applied consistently across 12 different models participating in the Chemistry Climate Model Initiative. Our analysis reveals that no statistically significant change in the frequency of SSWs will occur over the 21st century, irrespective of the metric used for the identification of the event. Changes in other SSWs characteristics, such as their duration and the tropospheric forcing, are also assessed: again, we find no evidence of future changes over the 21st century.