Articles | Volume 6, issue 4
https://doi.org/10.5194/wcd-6-1045-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/wcd-6-1045-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
06 Oct 2025
Research article |
| 06 Oct 2025
| 06 Oct 2025
QBOi El Niño–Southern Oscillation experiments: overview of the experimental design and ENSO modulation of the QBO
Yoshio Kawatani
CORRESPONDING AUTHOR
Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
Kevin Hamilton
International Pacific Research Center, University of Hawai‘i at Mānoa, Honolulu, HI, USA
Department of Atmospheric Sciences, University of Hawai‘i at Mānoa, Honolulu, HI, USA
Shingo Watanabe
Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Japan
Advanced Institute for Marine Ecosystem Change (WPI-AIMEC), Tohoku University, Sendai, Japan
Masakazu Taguchi
Aichi University of Education, Department of Science Education, Kariya, Japan
Federico Serva
Institute of Marine Sciences, National Research Council (ISMAR-CNR), Rome, Italy
James A. Anstey
Canadian Centre for Climate Modelling and Analysis (CCCma), Victoria, BC, Canada
Jadwiga H. Richter
U.S. National Science Foundation National Center for Atmospheric Research (NSF NCAR), Boulder, CO, USA
Neal Butchart
Met Office Hadley Centre, Exeter, UK
Clara Orbe
NASA Goddard Institute for Space Studies (GISS), New York, USA
Scott M. Osprey
National Centre for Atmospheric Science (NCAS), University of Oxford, Oxford, UK
Hiroaki Naoe
Meteorological Research Institute (MRI), Tsukuba, Japan
Dillon Elsbury
Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USA
NOAA/Chemical Sciences Laboratory, Boulder, CO, USA
Chih-Chieh Chen
U.S. National Science Foundation National Center for Atmospheric Research (NSF NCAR), Boulder, CO, USA
Javier García-Serrano
Group of Meteorology, Universitat de Barcelona, Barcelona, Spain
Barcelona Supercomputing Center (BSC), Barcelona, Spain
Anne Glanville
U.S. National Science Foundation National Center for Atmospheric Research (NSF NCAR), Boulder, CO, USA
Tobias Kerzenmacher
Institute of Meteorology and Climate Research–Atmospheric Trace Gases and Remote Sensing (IMK-ASF), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
François Lott
Laboratoire de Météorologie Dynamique (LMD), Paris, France
Froila M. Palmeiro
Group of Meteorology, Universitat de Barcelona, Barcelona, Spain
CMCC Foundation – Euro-Mediterranean Center on Climate Change, Bologna, Italy
Mijeong Park
U.S. National Science Foundation National Center for Atmospheric Research (NSF NCAR), Boulder, CO, USA
Stefan Versick
Institute of Meteorology and Climate Research–Atmospheric Trace Gases and Remote Sensing (IMK-ASF), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
Kohei Yoshida
Meteorological Research Institute (MRI), Tsukuba, Japan
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EGUsphere, https://doi.org/10.5194/egusphere-2026-2856, https://doi.org/10.5194/egusphere-2026-2856, 2026
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This study investigates the systematic biases in equatorial wave forcing of the quasi-biennial oscillation (QBO) by comparing internally generated and bias-corrected experiments using a multi-model ensemble. Although nudging effectively mitigates QBO biases, systematic biases in wave forcing are not fully resolved. The equatorial wave forcing in the lower stratosphere remains weaker than that in reanalyses, while an eastward wave forcing bias is observed in the mid-to-upper stratosphere.
James A. Anstey, Neal Butchart, Scott Osprey, Yoshio Kawatani, Kevin Hamilton, Jadwiga H. Richter, Tim Stockdale, Martin B. Andrews, Zhaoyang Chai, Paolo Davini, Dong-Chan Hong, Kai Huang, Aleena M. Jaison, Tobias Kerzenmacher, Jeff R. Knight, Pu Lin, Francois Lott, Yixiong Lu, Hiroaki Naoe, Federico Serva, Isla Simpson, Seok-Woo Son, Qi Tang, Shingo Watanabe, Jinbo Xie, and Kohei Yoshida
EGUsphere, https://doi.org/10.5194/egusphere-2026-1165, https://doi.org/10.5194/egusphere-2026-1165, 2026
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Martin B. Andrews, Neal Butchart, James A. Anstey, Ewa Bednarz, Dillon Elsbury, Jorge L. García-Franco, Vinay Kumar, Froila M. Palmeiro, Natasha E. Trencham, Kohei Yoshida, Zhaoyang Chai, Dong-Chan Hong, Kai Huang, Aleena M. Jaison, Yoshio Kawatani, Jeff R. Knight, Pu Lin, François Lott, Yixiong Lu, Hiroaki Naoe, Scott M. Osprey, Jadwiga H. Richter, Federico Serva, Seok-Woo Son, Qi Tang, Shingo Watanabe, and Jinbo Xie
EGUsphere, https://doi.org/10.5194/egusphere-2026-737, https://doi.org/10.5194/egusphere-2026-737, 2026
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The observed winds in the upper atmosphere over the equator have alternating easterly and westerly regions that descend towards the lower atmosphere before dissipating, with a period of approximately 28 months. This is known as the Quasi-Biennial Oscillation (QBO). The QBO is known to influence remote regions of the atmosphere. This paper details the results of multi-model experiments where the QBO is nudged towards the observed QBO allowing the assessment of these remote connections.
Dillon Elsbury, Federico Serva, Julie M. Caron, Seung-Yoon Back, Clara Orbe, Jadwiga H. Richter, James A. Anstey, Neal Butchart, Chih-Chieh Chen, Javier García-Serrano, Anne Glanville, Yoshio Kawatani, Tobias Kerzenmacher, Francois Lott, Hiroaki Naoe, Scott Osprey, Froila M. Palmeiro, Seok-Woo Son, Masakazu Taguchi, Stefan Versick, Shingo Watanabe, and Kohei Yoshida
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Hiroaki Naoe, Jorge L. García-Franco, Chang-Hyun Park, Mario Rodrigo, Froila M. Palmeiro, Federico Serva, Masakazu Taguchi, Kohei Yoshida, James A. Anstey, Javier García-Serrano, Seok-Woo Son, Yoshio Kawatani, Neal Butchart, Kevin Hamilton, Chih-Chieh Chen, Anne Glanville, Tobias Kerzenmacher, François Lott, Clara Orbe, Scott Osprey, Mijeong Park, Jadwiga H. Richter, Stefan Versick, and Shingo Watanabe
Weather Clim. Dynam., 6, 1419–1442, https://doi.org/10.5194/wcd-6-1419-2025, https://doi.org/10.5194/wcd-6-1419-2025, 2025
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Links between the stratospheric Quasi-Biennial Oscillation (QBO) and atmospheric circulations in the tropics, subtropics, and polar regions, as well as their modulation by the El Nino–Southern Oscillation, are examined through model experiments. The QBO–polar vortex connection is reproduced by a multi-model ensemble at about half the observed amplitude. Weak performance of QBO signals in these regions is likely due to unrealistically weak QBO amplitudes in the lower stratosphere.
Masatomo Fujiwara, Patrick Martineau, Jonathon S. Wright, Marta Abalos, Petr Šácha, Yoshio Kawatani, Sean M. Davis, Thomas Birner, and Beatriz M. Monge-Sanz
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Kai Huang, Chang-Hyun Park, Seung-Yoon Back, Jorge L. García-Franco, Hera Kim, Pu Lin, Scott Osprey, Jadwiga Richter, Chih-Chieh Chen, Seok-Woo Son, Shigeo Yoden, Yuna Lim, Neal Butchart, James Anstey, Yoshio Kawatani, Martin B. Andrews, Francois Lott, Yixiong Lu, Zhaoyang Chai, Nan Rosenbloom, Qi Tang, Jinbo Xie, Federico Serva, Dong-Chan Hong, Shingo Watanabe, Aleena M. Jaison, Hiroaki Naoe, and Kohei Yoshida
EGUsphere, https://doi.org/10.5194/egusphere-2026-3744, https://doi.org/10.5194/egusphere-2026-3744, 2026
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
Short summary
Short summary
The tropical atmosphere has large-scale wind and rainfall patterns shaping weather worldwide. Winds high above the tropics are thought to influence a major tropical rainfall system, but climate models fail to reproduce this link. We tested 12 climate models after constraining their high-altitude winds to match observations. Although the winds then matched, the models failed to capture the tropical response, as they did not realistically simulate it. Improving this is key to better prediction.
Chaim I. Garfinkel, David Avisar, Scott M. Osprey, Doug Smith, Jian Rao, and Jonathon S. Wright
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The Quasi-biennial Oscillation (QBO) dominates variability in the tropical stratosphere, & it impacts surface climate in several parts of the world. However, climate models have been shown to systematically under-estimate the influence of the QBO. Here, we re-evaluate this finding using much larger ensemble sizes than have been previously available based on four separate models. We find that the models are comparatively more successful in capturing QBO influences than reported by previous work.
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This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
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This study investigates the systematic biases in equatorial wave forcing of the quasi-biennial oscillation (QBO) by comparing internally generated and bias-corrected experiments using a multi-model ensemble. Although nudging effectively mitigates QBO biases, systematic biases in wave forcing are not fully resolved. The equatorial wave forcing in the lower stratosphere remains weaker than that in reanalyses, while an eastward wave forcing bias is observed in the mid-to-upper stratosphere.
Ilaria Quaglia, Daniele Visioni, Ewa M. Bednarz, Yunqian Zhu, Georgiy Stenchikov, Valentina Aquila, Cheng-Cheng Liu, Graham W. Mann, Yifeng Peng, Takashi Sekiya, Simone Tilmes, Xinyue Wang, Shingo Watanabe, Pengfei Yu, Jun Zhang, Wandi Yu, and Zhihong Zhuo
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On January 15, 2022, the Hunga volcano eruption released unprecedented amounts of water vapor into the atmosphere alongside a modest amount of SO2. In this work we analyse results from multiple Earth system models. The models agree that the eruption led to small negative radiative forcing from sulfate aerosols and that the contribution from water vapor was minimal. Therefore, the Hunga eruption cannot explain the exceptional surface warming observed in 2023.
Walker Raymond Lee, Daniele Visioni, Benjamin Moore Wagman, Christopher Robert Wentland, Ben Kravitz, Shingo Watanabe, Takashi Sekiya, Andy Jones, Jim Haywood, Matthew Henry, and Ewa Monika Bednarz
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Daniele Visioni, Alan Robock, Alistair Duffey, Matthew Henry, Haruki Hirasawa, Walker R. Lee, Cindy Wang, Kelsey Roberts, Shingo Watanabe, Michelle S. Reboita, Masahiro Sugiyama, Ben Kravitz, Jim Haywood, Simone Tilmes, Frederic Bonou, Jack Chen, Timofei Sukodolov, Sandro Vattioni, Andrin Jörimann, Diego Villanueva, Ryan Vella, Paul Farron, Ewa M. Bednarz, Ulrike Niemeier, Colleen Golja, and Juan A. Anel
EGUsphere, https://doi.org/10.5194/egusphere-2026-2417, https://doi.org/10.5194/egusphere-2026-2417, 2026
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
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The Geoengineering Model Intercomparison Project is a coordinated international model intercomparison effort aiming to provide robust experimental protocols for simulations of various Solar Radiation Modification (SRM) methods. In this manuscript, we describe a list of novel experiments decided by the community, to be run by climate models to better understand sources of uncertainty in SRM. We also show and discuss some preliminary results from a few climate models.
James A. Anstey, Neal Butchart, Scott Osprey, Yoshio Kawatani, Kevin Hamilton, Jadwiga H. Richter, Tim Stockdale, Martin B. Andrews, Zhaoyang Chai, Paolo Davini, Dong-Chan Hong, Kai Huang, Aleena M. Jaison, Tobias Kerzenmacher, Jeff R. Knight, Pu Lin, Francois Lott, Yixiong Lu, Hiroaki Naoe, Federico Serva, Isla Simpson, Seok-Woo Son, Qi Tang, Shingo Watanabe, Jinbo Xie, and Kohei Yoshida
EGUsphere, https://doi.org/10.5194/egusphere-2026-1165, https://doi.org/10.5194/egusphere-2026-1165, 2026
Short summary
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We describe experiments where modelled tropical stratosphere winds are adjusted by "nudging" them toward realistic time-evolving eastward and westward Quasi-Biennial Oscillation (QBO) winds. The effects of this bias correction on other atmospheric processes, such as the stratospheric polar vortex or tropical waves that force the QBO, can then be assessed. We describe details of the experiments, the multi-model ensemble that has performed them, and basic validation of the nudging response.
Marta Abalos, Thomas Birner, Andreas Chrysanthou, Sean Davis, Alvaro de la Cámara, Sandip Dhomse, Hella Garny, Michaela I. Hegglin, Daan Hubert, Oksana Ivaniha, James Keeble, Marianna Linz, Daniele Minganti, Jessica Neu, David Plummer, Laura Saunders, Kasturi Shah, Gabriele Stiller, Kleareti Tourpali, Darryn Waugh, Nathan Luke Abraham, Hideharu Akiyoshi, Martyn P. Chipperfield, Patrick Jöckel, Béatrice Josse, Marion Marchand, Patrick Martineau, Olaf Morgenstern, Timofei Sukhodolov, Shingo Watanabe, and Yousuke Yamashita
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Beth Dingley, James A. Anstey, Marta Abalos, Carsten Abraham, Tommi Bergman, Lisa Bock, Sonya Fiddes, Birgit Hassler, Ryan J. Kramer, Fei Luo, Fiona M. O'Connor, Petr Šácha, Isla R. Simpson, Laura J. Wilcox, and Mark D. Zelinka
Geosci. Model Dev., 19, 2945–2984, https://doi.org/10.5194/gmd-19-2945-2026, https://doi.org/10.5194/gmd-19-2945-2026, 2026
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This manuscript defines as a list of variables and scientific opportunities which are requested from the Coupled Model Intercomparison Project Phase 7 (CMIP7) Assessment Fast Track to address open atmospheric science questions. The list reflects the output of a large public community engagement effort, coordinated across autumn 2025 through to summer 2025.
Chloe Mackallah, Martin Juckes, James Anstey, Beth Dingley, Charlotte Pascoe, Gaëlle Rigoudy, Marie-Pierre Moine, Tomas Lovato, Alison Pamment, Martin Schupfner, Michio Kawamiya, Tommi Bergman, Charles Koven, Eleanor O'Rourke, Briony Turner, Daniel Ellis, and Matthew Mizielinski
EGUsphere, https://doi.org/10.5194/egusphere-2026-1641, https://doi.org/10.5194/egusphere-2026-1641, 2026
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This paper describes the creation of a new set of output data requirements for upcoming global climate model experiments performed for CMIP7, an international climate modelling activity. Experts from the community helped to co-create a database that describes which data should be produced, and the scientific justifications behind these choices. It supports growing climate research and policy needs by linking experiments and variables to scientific objectives and real‑world applications.
Meghan Brehon, Susann Tegtmeier, Adam Bourassa, Sean M. Davis, Udo Grabowski, Tobias Kerzenmacher, and Gabriele Stiller
Atmos. Chem. Phys., 26, 3743–3764, https://doi.org/10.5194/acp-26-3743-2026, https://doi.org/10.5194/acp-26-3743-2026, 2026
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Gholam Ali Hoshyaripour, Andreas Baer, Sascha Bierbauer, Julia Bruckert, Dominik Brunner, Jochen Förstner, Arash Hamzehloo, Valentin Hanft, Corina Keller, Martina Klose, Pankaj Kumar, Patrick Ludwig, Enrico Metzner, Lisa Muth, Andreas Pauling, Nikolas Porz, Maryam Ramezani Ziarani, Thomas Reddmann, Luca Reißig, Roland Ruhnke, Khompat Satitkovitchai, Axel Seifert, Miriam Sinnhuber, Michael Steiner, Stefan Versick, Heike Vogel, Michael Weimer, Sven Werchner, and Corinna Hoose
Geosci. Model Dev., 19, 1645–1681, https://doi.org/10.5194/gmd-19-1645-2026, https://doi.org/10.5194/gmd-19-1645-2026, 2026
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This paper presents recent advances in ICON-ART, a modeling system that simulates atmospheric composition – such as gases and particles – and their interactions with weather and climate. By integrating updated chemistry, emissions, and aerosol processes, ICON-ART enables detailed, scale-spanning simulations. It supports both scientific research and operational forecasts, contributing to improved air quality, weather and climate predictions.
Sean Davis, William Ball, Yue Jia, Gabriel Chiodo, Justin Alsing, James Keeble, Hideharu Akiyoshi, Carlo Arosio, Ewa Bednarz, Andreas Chrysanthou, Melanie Coldewey-Egbers, Robert Damadeo, Sandip Dhomse, Mohamadou Diallo, Simone Dietmuller, Roland Eichinger, Stacey Frith, Birgit Hassler, Michaela Hegglin, Daan Hubert, Patrick Jöckel, Béatrice Josse, Natalya Kramarova, Diego Loyola, Eliane Maillard Barras, Marion Marchand, Olaf Morgenstern, David Plummer, Robert Portmann, Karen Rosenlof, Alexei Rozanov, Viktoria Sofieva, Johannes Staehelin, Timofei Sukhodolov, Kleareti Tourpali, Ronald Van der A, H. J. Ray Wang, Krzysztof Wargan, Shingo Watanabe, Mark Weber, Jeannette Wild, Yousuke Yamashita, and Jerry Ziemke
EGUsphere, https://doi.org/10.5194/egusphere-2026-532, https://doi.org/10.5194/egusphere-2026-532, 2026
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This study investigates how tropical ozone levels have changed since 2000 in chemistry climate models and satellite observations to determine how well they agree with one another, and to see if current trends can help predict future levels. At some, satellite records disagree significantly on the magnitude of ozone changes. The study shows a connection between recent ozone trends and future ozone levels, suggesting that satellite measurements could help constrain future ozone changes.
Blanca Ayarzagüena, Amy H. Butler, Peter Hitchcock, Chaim I. Garfinkel, Zac D. Lawrence, Wuhan Ning, Philip Rupp, Zheng Wu, Hilla Afargan-Gerstman, Natalia Calvo, Alvaro de la Cámara, Martin Jucker, Gerbrand Koren, Daniel De Maeseneire, Gloria L. Manney, Marisol Osman, Masakazu Taguchi, Cory Barton, Dong-Chan Hong, Yu-Kyung Hyun, Hera Kim, Jeff Knight, Piero Malguzzi, Daniele Mastrangelo, Jiyoung Oh, Inna Polichtchouk, Jadwiga H. Richter, Isla R. Simpson, Seok-Woo Son, Damien Specq, and Tim Stockdale
Weather Clim. Dynam., 7, 411–437, https://doi.org/10.5194/wcd-7-411-2026, https://doi.org/10.5194/wcd-7-411-2026, 2026
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Sudden Stratospheric Warmings (SSWs) are known to follow a sustained wave dissipation in the stratosphere, which depends on both the tropospheric and stratospheric states. However, the relative role of each state is still unclear. Using a new set of subseasonal to seasonal forecasts, we show that the stratospheric state does not drastically affect the precursors of three recent SSWs, but modulates the stratospheric wave activity, with impacts depending on SSW features.
Martin B. Andrews, Neal Butchart, James A. Anstey, Ewa Bednarz, Dillon Elsbury, Jorge L. García-Franco, Vinay Kumar, Froila M. Palmeiro, Natasha E. Trencham, Kohei Yoshida, Zhaoyang Chai, Dong-Chan Hong, Kai Huang, Aleena M. Jaison, Yoshio Kawatani, Jeff R. Knight, Pu Lin, François Lott, Yixiong Lu, Hiroaki Naoe, Scott M. Osprey, Jadwiga H. Richter, Federico Serva, Seok-Woo Son, Qi Tang, Shingo Watanabe, and Jinbo Xie
EGUsphere, https://doi.org/10.5194/egusphere-2026-737, https://doi.org/10.5194/egusphere-2026-737, 2026
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The observed winds in the upper atmosphere over the equator have alternating easterly and westerly regions that descend towards the lower atmosphere before dissipating, with a period of approximately 28 months. This is known as the Quasi-Biennial Oscillation (QBO). The QBO is known to influence remote regions of the atmosphere. This paper details the results of multi-model experiments where the QBO is nudged towards the observed QBO allowing the assessment of these remote connections.
Dillon Elsbury, Federico Serva, Julie M. Caron, Seung-Yoon Back, Clara Orbe, Jadwiga H. Richter, James A. Anstey, Neal Butchart, Chih-Chieh Chen, Javier García-Serrano, Anne Glanville, Yoshio Kawatani, Tobias Kerzenmacher, Francois Lott, Hiroaki Naoe, Scott Osprey, Froila M. Palmeiro, Seok-Woo Son, Masakazu Taguchi, Stefan Versick, Shingo Watanabe, and Kohei Yoshida
Weather Clim. Dynam., 7, 317–339, https://doi.org/10.5194/wcd-7-317-2026, https://doi.org/10.5194/wcd-7-317-2026, 2026
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We used climate models to test how constant El Niño and La Niña ocean conditions shape the Madden-Julian Oscillation during northern winter. El Niño made this weather pattern move faster, while La Niña slowed it down. The Quasi-Biennial Oscillation, a repeating wind pattern high in the atmosphere, had little effect. This shows that long-lasting ocean conditions mainly drive the changes we found.
Andrin Jörimann, Timofei Sukhodolov, Simone Tilmes, David Plummer, Shingo Watanabe, Hideharu Akiyoshi, Gabriel Chiodo, Daniele Visioni, Sandro Vattioni, Eugene Rozanov, Ewa M. Bednarz, Béatrice Jossé, Yousuke Yamashita, and Thomas Peter
EGUsphere, https://doi.org/10.5194/egusphere-2026-444, https://doi.org/10.5194/egusphere-2026-444, 2026
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We study a future scenario where artificial stratospheric aerosol injections counter medium climate change, to understand possible negative side effects like ozone depletion. The injected aerosol layer is implemented uniformly in five climate models, which eliminates some uncertainty from model-specific aerosol evolution. The models agree well on where and how key thermodynamical (heating, circulation) and chemical processes change, however, the strength of the change varies considerably.
Ewa M. Bednarz, Amy H. Butler, James M. Haywood, Matthew Henry, Andy Jones, Ben Kravitz, Walker R. Lee, Douglas G. MacMartin, Amanda C. Maycock, Takashi Sekiya, Shingo Watanabe, and Daniele Visioni
EGUsphere, https://doi.org/10.5194/egusphere-2026-310, https://doi.org/10.5194/egusphere-2026-310, 2026
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An assessment of the potential impacts of Stratospheric Aerosol Injection, a proposed method to offset global warming, on stratospheric ozone projections over the 21st century using the new multi-model GeoMIP G6-1.5K-SAI experiment. We discuss drivers of the responses, identify areas of model agreement and disagreement and sources of uncertainty. Our results highlight the need to assess any projected SAI impacts in wider strategy and scenario dimension using a multi-model framework.
Clara Orbe, Alison Ming, Gabriel Chiodo, Michael Prather, Mohamadou Diallo, Qi Tang, Andreas Chrysanthou, Hiroaki Naoe, Xin Zhou, Irina Thaler, Dillon Elsbury, Ewa Bednarz, Jonathon S. Wright, Aaron Match, Shingo Watanabe, James Anstey, Tobias Kerzenmacher, Stefan Versick, Marion Marchand, Feng Li, and James Keeble
Geosci. Model Dev., 19, 773–794, https://doi.org/10.5194/gmd-19-773-2026, https://doi.org/10.5194/gmd-19-773-2026, 2026
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The quasi-biennial oscillation (QBO) is the main source of wind fluctuations in the tropical stratosphere, which can couple to surface climate. However, models do a poor job of simulating the QBO in the lower stratosphere, for reasons that remain unclear. One possibility is that models do not completely represent how ozone influences the QBO-associated wind variations. Here we propose a multi-model framework for assessing how ozone influences the QBO in recent past and future climates.
Jingyu Wang, Gabriel Chiodo, Blanca Ayarzagüena, William T. Ball, Mohamadou Diallo, Birgit Hassler, James Keeble, Peer Nowack, Clara Orbe, Sandro Vattioni, and Timofei Sukhodolov
Atmos. Chem. Phys., 25, 17819–17844, https://doi.org/10.5194/acp-25-17819-2025, https://doi.org/10.5194/acp-25-17819-2025, 2025
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We analyzed the ozone response under elevated CO2 using the data from CMIP6 DECK experiments. We then examined the relations between ozone response and changes in temperature and circulation to identify the drivers of ozone change. The climate feedback of ozone is investigated through offline calculations and by comparing models with and without interactive chemistry. We find that ozone–climate interactions are important for Earth system models and thus should be considered in future model development.
Hiroaki Naoe, Jorge L. García-Franco, Chang-Hyun Park, Mario Rodrigo, Froila M. Palmeiro, Federico Serva, Masakazu Taguchi, Kohei Yoshida, James A. Anstey, Javier García-Serrano, Seok-Woo Son, Yoshio Kawatani, Neal Butchart, Kevin Hamilton, Chih-Chieh Chen, Anne Glanville, Tobias Kerzenmacher, François Lott, Clara Orbe, Scott Osprey, Mijeong Park, Jadwiga H. Richter, Stefan Versick, and Shingo Watanabe
Weather Clim. Dynam., 6, 1419–1442, https://doi.org/10.5194/wcd-6-1419-2025, https://doi.org/10.5194/wcd-6-1419-2025, 2025
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Links between the stratospheric Quasi-Biennial Oscillation (QBO) and atmospheric circulations in the tropics, subtropics, and polar regions, as well as their modulation by the El Nino–Southern Oscillation, are examined through model experiments. The QBO–polar vortex connection is reproduced by a multi-model ensemble at about half the observed amplitude. Weak performance of QBO signals in these regions is likely due to unrealistically weak QBO amplitudes in the lower stratosphere.
Yasuto Watanabe, Makoto Deushi, and Kohei Yoshida
Clim. Past, 21, 2243–2261, https://doi.org/10.5194/cp-21-2243-2025, https://doi.org/10.5194/cp-21-2243-2025, 2025
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This study uses an Earth System Model, MRI-ESM2.0, to demonstrate that the atmospheric ozone distribution during warm interglacial periods is modified by the changes in the Earth's orbital parameters. We further show that the change in atmospheric ozone works to cool the surface at the high-latitude regions of the northern hemisphere in the past warm interglacial periods (6 and 127 thousand years ago), while its impact is small around Antarctica.
Ewa M. Bednarz, Valentina Aquila, Amy H. Butler, Peter Colarco, Eric Fleming, Freja F. Østerstrøm, David Plummer, Ilaria Quaglia, William Randel, Michelle L. Santee, Takashi Sekiya, Simone Tilmes, Xinyue Wang, Shingo Watanabe, Wandi Yu, Jun Zhang, Yunqian Zhu, and Zhihong Zhuo
EGUsphere, https://doi.org/10.5194/egusphere-2025-4609, https://doi.org/10.5194/egusphere-2025-4609, 2025
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The 2022 Hunga eruption injected unprecedented quantities of water vapor into the stratosphere, alongside modest amounts of aerosol precursors. We assess its impacts on stratospheric ozone layer using a multi-model ensemble of chemistry-climate simulations. The results confirm the eruption's role in modulating SH mid and high latitudes ozone abundances in the short term, and discuss the different chemical and dynamical processes driving those changes as well as the role of natural variability.
Hongyue Wang, Mijeong Park, Mengchu Tao, Cristina Peña-Ortiz, Nuria P. Plaza-Martin, Felix Ploeger, and Paul Konopka
Atmos. Chem. Phys., 25, 14703–14718, https://doi.org/10.5194/acp-25-14703-2025, https://doi.org/10.5194/acp-25-14703-2025, 2025
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We investigate how water vapor in the upper atmosphere gains moisture during the Asian and North American monsoons using a simplified modeling approach. Our results show that the Asian monsoon is mainly controlled by large-scale temperature, whereas the North American monsoon may be more influenced by convective moistening. These differences point to distinct mechanisms shaping moisture transport in the two monsoon systems.
Zhihong Zhuo, Xinyue Wang, Yunqian Zhu, Wandi Yu, Ewa M. Bednarz, Eric Fleming, Peter R. Colarco, Shingo Watanabe, David Plummer, Georgiy Stenchikov, William Randel, Adam Bourassa, Valentina Aquila, Takashi Sekiya, Mark R. Schoeberl, Simone Tilmes, Jun Zhang, Paul J. Kushner, and Francesco S. R. Pausata
Atmos. Chem. Phys., 25, 13161–13176, https://doi.org/10.5194/acp-25-13161-2025, https://doi.org/10.5194/acp-25-13161-2025, 2025
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The 2022 Hunga eruption caused unprecedented stratospheric water injection, triggering unique atmospheric impacts. This study combines observations and model simulations, projecting a stratospheric water vapor anomaly lasting 4–7 years, with significant temperature variations and ozone depletion in the upper atmosphere lasting 7–10 years. These findings offer critical insights into the role of stratospheric water vapor in shaping climate and atmospheric chemistry.
Raina Roy, Julie M. Arblaster, Matthew C. Wheeler, Eun-Pa Lim, and Jadwiga H. Richter
EGUsphere, https://doi.org/10.5194/egusphere-2025-4453, https://doi.org/10.5194/egusphere-2025-4453, 2025
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A key pattern of tropical weather, the Madden-Julian Oscillation, has become significantly harder to predict since the late 1990s. We discovered this by comparing forecasts from major models across two time periods. The decrease in forecast skill is linked to changes in large-scale climate patterns, not just model errors. This means to improve long-range weather forecasts, models must better simulate how these large-scale patterns interact with tropical weather.
Yunqian Zhu, Hideharu Akiyoshi, Valentina Aquila, Elizabeth Asher, Ewa M. Bednarz, Slimane Bekki, Christoph Brühl, Amy H. Butler, Parker Case, Simon Chabrillat, Gabriel Chiodo, Margot Clyne, Peter R. Colarco, Sandip Dhomse, Lola Falletti, Eric Fleming, Ben Johnson, Andrin Jörimann, Mahesh Kovilakam, Gerbrand Koren, Ales Kuchar, Nicolas Lebas, Qing Liang, Cheng-Cheng Liu, Graham Mann, Michael Manyin, Marion Marchand, Olaf Morgenstern, Paul Newman, Luke D. Oman, Freja F. Østerstrøm, Yifeng Peng, David Plummer, Ilaria Quaglia, William Randel, Samuel Rémy, Takashi Sekiya, Stephen Steenrod, Timofei Sukhodolov, Simone Tilmes, Kostas Tsigaridis, Rei Ueyama, Daniele Visioni, Xinyue Wang, Shingo Watanabe, Yousuke Yamashita, Pengfei Yu, Wandi Yu, Jun Zhang, and Zhihong Zhuo
Geosci. Model Dev., 18, 5487–5512, https://doi.org/10.5194/gmd-18-5487-2025, https://doi.org/10.5194/gmd-18-5487-2025, 2025
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To understand the climate impact of the 2022 Hunga volcanic eruption, we developed a climate model–observation comparison project. The paper describes the protocols and models that participate in the experiments. We designed several experiments to achieve our goals of this activity: (1) to evaluate the climate model performance and (2) to understand the Earth system responses to this eruption.
Jinbo Xie, Qi Tang, Michael Prather, Jadwiga Richter, and Shixuan Zhang
Atmos. Chem. Phys., 25, 9315–9333, https://doi.org/10.5194/acp-25-9315-2025, https://doi.org/10.5194/acp-25-9315-2025, 2025
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Analysis of the interaction between the climate and ozone in the stratosphere is complicated by the inability of climate models to simulate the quasi-biennial oscillation (QBO) – an important climate mode in the stratosphere. We use a set of model simulations that realistically simulate QBO and a novel ozone diagnostic tool to separate temperature- and circulation-driven QBO impacts. These are important for diagnosing model–model differences in QBO–ozone responses for climate projections.
Lena Feld, Pablo Schmid, Marios Mermigkas, Dimitrios Balis, Jochen Gross, Darko Dubravica, Carlos Alberti, Benedikt Herkommer, Stefan Versick, Roland Ruhnke, Frank Hase, and Peter Braesicke
EGUsphere, https://doi.org/10.5194/egusphere-2025-639, https://doi.org/10.5194/egusphere-2025-639, 2025
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Our goal is to measure CO2 emissions from cities, to verify and improve our knowledge of reported anthropogenic emissions. We use atmospheric measurements and simulations of CO2 transport to find an independent estimate. This study investigates the CO2 emissions of the city of Thessaloniki, where the reported emissions differ. The data we collected indicates that the emissions are larger than stated by the ODIAC inventory, which we used for our simulations.
Verónica Martínez-Andradas, Alvaro de la Cámara, Pablo Zurita-Gotor, François Lott, and Federico Serva
Weather Clim. Dynam., 6, 329–343, https://doi.org/10.5194/wcd-6-329-2025, https://doi.org/10.5194/wcd-6-329-2025, 2025
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Global circulation model biases are present when simulating sudden stratospheric warmings (SSWs). These are important extreme phenomena that occur in the wintertime stratosphere, driven by the breaking of atmospheric waves. The present work shows that there is a large spread of the wave forcing during the development of SSWs in different models. In the mesosphere, gravity waves are found to force advection of the residual circulation, while planetary waves tend to decelerate the wind.
Mari R. Tye, Ming Ge, Jadwiga H. Richter, Ethan D. Gutmann, Allyson Rugg, Cindy L. Bruyère, Sue Ellen Haupt, Flavio Lehner, Rachel McCrary, Andrew J. Newman, and Andy Wood
Hydrol. Earth Syst. Sci., 29, 1117–1133, https://doi.org/10.5194/hess-29-1117-2025, https://doi.org/10.5194/hess-29-1117-2025, 2025
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There is a perceived mismatch between the spatial scales on which global climate models can produce data and those needed for water management decisions. However, poor communication of specific metrics relevant to local decisions is also a problem. We assessed the credibility of a set of water management decision metrics in the Community Earth System Model v2 (CESM2). CESM2 shows potentially greater use of its output in long-range water management decisions.
Chaim I. Garfinkel, Zachary D. Lawrence, Amy H. Butler, Etienne Dunn-Sigouin, Irene Erner, Alexey Y. Karpechko, Gerbrand Koren, Marta Abalos, Blanca Ayarzagüena, David Barriopedro, Natalia Calvo, Alvaro de la Cámara, Andrew Charlton-Perez, Judah Cohen, Daniela I. V. Domeisen, Javier García-Serrano, Neil P. Hindley, Martin Jucker, Hera Kim, Robert W. Lee, Simon H. Lee, Marisol Osman, Froila M. Palmeiro, Inna Polichtchouk, Jian Rao, Jadwiga H. Richter, Chen Schwartz, Seok-Woo Son, Masakazu Taguchi, Nicholas L. Tyrrell, Corwin J. Wright, and Rachel W.-Y. Wu
Weather Clim. Dynam., 6, 171–195, https://doi.org/10.5194/wcd-6-171-2025, https://doi.org/10.5194/wcd-6-171-2025, 2025
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Variability in the extratropical stratosphere and troposphere is coupled, and because of the longer timescales characteristic of the stratosphere, this allows for a window of opportunity for surface prediction. This paper assesses whether models used for operational prediction capture these coupling processes accurately. We find that most processes are too weak; however downward coupling from the lower stratosphere to the near surface is too strong.
Lauren R. Marshall, Anja Schmidt, Andrew P. Schurer, Nathan Luke Abraham, Lucie J. Lücke, Rob Wilson, Kevin J. Anchukaitis, Gabriele C. Hegerl, Ben Johnson, Bette L. Otto-Bliesner, Esther C. Brady, Myriam Khodri, and Kohei Yoshida
Clim. Past, 21, 161–184, https://doi.org/10.5194/cp-21-161-2025, https://doi.org/10.5194/cp-21-161-2025, 2025
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Large volcanic eruptions have caused temperature deviations over the past 1000 years; however, climate model results and reconstructions of surface cooling using tree rings do not match. We explore this mismatch using the latest models and find a better match to tree-ring reconstructions for some eruptions. Our results show that the way in which eruptions are simulated in models matters for the comparison to tree-rings, particularly regarding the spatial spread of volcanic aerosol.
Weiyu Zhang, Kwinten Van Weverberg, Cyril J. Morcrette, Wuhu Feng, Kalli Furtado, Paul R. Field, Chih-Chieh Chen, Andrew Gettelman, Piers M. Forster, Daniel R. Marsh, and Alexandru Rap
Atmos. Chem. Phys., 25, 473–489, https://doi.org/10.5194/acp-25-473-2025, https://doi.org/10.5194/acp-25-473-2025, 2025
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Contrail cirrus is the largest, but also most uncertain, contribution of aviation to global warming. We evaluate, for the first time, the impact of the host climate model on contrail cirrus properties. Substantial differences exist between contrail cirrus formation, persistence, and radiative effects in the host climate models. Reliable contrail cirrus simulations require advanced representation of cloud optical properties and microphysics, which should be better constrained by observations.
Aleena M. Jaison, Lesley J. Gray, Scott M. Osprey, Jeff R. Knight, and Martin B. Andrews
Weather Clim. Dynam., 5, 1489–1504, https://doi.org/10.5194/wcd-5-1489-2024, https://doi.org/10.5194/wcd-5-1489-2024, 2024
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Models have biases in semi-annual oscillation (SAO) representation, mainly due to insufficient eastward wave forcing. We examined if the bias is from increased wave absorption due to circulation biases in the low–middle stratosphere. Alleviating biases at lower altitudes improves the SAO, but substantial bias remains. Alternative methods like gravity wave parameterization changes should be explored to enhance the modelled SAO, potentially improving sudden stratospheric warming predictability.
Andrew Gettelman, Richard Forbes, Roger Marchand, Chih-Chieh Chen, and Mark Fielding
Geosci. Model Dev., 17, 8069–8092, https://doi.org/10.5194/gmd-17-8069-2024, https://doi.org/10.5194/gmd-17-8069-2024, 2024
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Supercooled liquid clouds (liquid clouds colder than 0°C) are common at higher latitudes (especially over the Southern Ocean) and are critical for constraining climate projections. We compare a single-column version of a weather model to observations with two different cloud schemes and find that both the dynamical environment and atmospheric aerosols are important for reproducing observations.
Sebastian Rhode, Peter Preusse, Jörn Ungermann, Inna Polichtchouk, Kaoru Sato, Shingo Watanabe, Manfred Ern, Karlheinz Nogai, Björn-Martin Sinnhuber, and Martin Riese
Atmos. Meas. Tech., 17, 5785–5819, https://doi.org/10.5194/amt-17-5785-2024, https://doi.org/10.5194/amt-17-5785-2024, 2024
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We investigate the capabilities of a proposed satellite mission, CAIRT, for observing gravity waves throughout the middle atmosphere and present the necessary methodology for in-depth wave analysis. Our findings suggest that such a satellite mission is highly capable of resolving individual wave parameters and could give new insights into the role of gravity waves in general atmospheric circulation and atmospheric processes.
Paula L. M. Gonzalez, Lesley J. Gray, Stergios Misios, Scott Osprey, and Hedi Ma
EGUsphere, https://doi.org/10.5194/egusphere-2024-2487, https://doi.org/10.5194/egusphere-2024-2487, 2024
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This study has examined a set of reanalyses, both modern and 20th Century, to evaluate the robustness of the signatures of the 11-yr solar cycle in the North Atlantic climate. We find a robust response to the 11-yr solar cycle over the North Atlantic sector with a positive SLP anomaly north of the Azores region at lags of +2–3 years following solar maximum. An ocean reanalysis dataset shows that thermal inertia of the ocean could explain the lag in the SC response.
Masatomo Fujiwara, Patrick Martineau, Jonathon S. Wright, Marta Abalos, Petr Šácha, Yoshio Kawatani, Sean M. Davis, Thomas Birner, and Beatriz M. Monge-Sanz
Atmos. Chem. Phys., 24, 7873–7898, https://doi.org/10.5194/acp-24-7873-2024, https://doi.org/10.5194/acp-24-7873-2024, 2024
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A climatology of the major variables and terms of the transformed Eulerian-mean (TEM) momentum and thermodynamic equations from four global atmospheric reanalyses is evaluated. The spread among reanalysis TEM momentum balance terms is around 10 % in Northern Hemisphere winter and up to 50 % in Southern Hemisphere winter. The largest uncertainties in the thermodynamic equation (about 50 %) are in the vertical advection, which does not show a structure consistent with the differences in heating.
Cheng Zheng, Yutian Wu, Mingfang Ting, and Clara Orbe
Atmos. Chem. Phys., 24, 6965–6985, https://doi.org/10.5194/acp-24-6965-2024, https://doi.org/10.5194/acp-24-6965-2024, 2024
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Trace gases and aerosols in the Arctic, which typically originate from midlatitude and tropical emission regions, modulate the Arctic climate via their radiative and chemistry impacts. Thus, long-range transport of these substances is important for understanding the current and the future change of Arctic climate. By employing chemistry–climate models, we explore how year-to-year variations in the atmospheric circulation modulate atmospheric long-range transport into the Arctic.
Daniele Visioni, Alan Robock, Jim Haywood, Matthew Henry, Simone Tilmes, Douglas G. MacMartin, Ben Kravitz, Sarah J. Doherty, John Moore, Chris Lennard, Shingo Watanabe, Helene Muri, Ulrike Niemeier, Olivier Boucher, Abu Syed, Temitope S. Egbebiyi, Roland Séférian, and Ilaria Quaglia
Geosci. Model Dev., 17, 2583–2596, https://doi.org/10.5194/gmd-17-2583-2024, https://doi.org/10.5194/gmd-17-2583-2024, 2024
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This paper describes a new experimental protocol for the Geoengineering Model Intercomparison Project (GeoMIP). In it, we describe the details of a new simulation of sunlight reflection using the stratospheric aerosols that climate models are supposed to run, and we explain the reasons behind each choice we made when defining the protocol.
John T. Fasullo, Jean-Christophe Golaz, Julie M. Caron, Nan Rosenbloom, Gerald A. Meehl, Warren Strand, Sasha Glanville, Samantha Stevenson, Maria Molina, Christine A. Shields, Chengzhu Zhang, James Benedict, Hailong Wang, and Tony Bartoletti
Earth Syst. Dynam., 15, 367–386, https://doi.org/10.5194/esd-15-367-2024, https://doi.org/10.5194/esd-15-367-2024, 2024
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Climate model large ensembles provide a unique and invaluable means for estimating the climate response to external forcing agents and quantify contrasts in model structure. Here, an overview of the Energy Exascale Earth System Model (E3SM) version 2 large ensemble is given along with comparisons to large ensembles from E3SM version 1 and versions 1 and 2 of the Community Earth System Model. The paper provides broad and important context for users of these ensembles.
Timothy P. Banyard, Corwin J. Wright, Scott M. Osprey, Neil P. Hindley, Gemma Halloran, Lawrence Coy, Paul A. Newman, Neal Butchart, Martina Bramberger, and M. Joan Alexander
Atmos. Chem. Phys., 24, 2465–2490, https://doi.org/10.5194/acp-24-2465-2024, https://doi.org/10.5194/acp-24-2465-2024, 2024
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In 2019/2020, the tropical stratospheric wind phenomenon known as the quasi-biennial oscillation (QBO) was disrupted for only the second time in the historical record. This was poorly forecasted, and we want to understand why. We used measurements from the first Doppler wind lidar in space, Aeolus, to observe the disruption in an unprecedented way. Our results reveal important differences between Aeolus and the ERA5 reanalysis that affect the timing of the disruption's onset and its evolution.
Tiehan Zhou, Kevin J. DallaSanta, Clara Orbe, David H. Rind, Jeffrey A. Jonas, Larissa Nazarenko, Gavin A. Schmidt, and Gary Russell
Atmos. Chem. Phys., 24, 509–532, https://doi.org/10.5194/acp-24-509-2024, https://doi.org/10.5194/acp-24-509-2024, 2024
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The El Niño–Southern Oscillation (ENSO) tends to speed up and slow down the phase speed of the Quasi-Biennial Oscillation (QBO) during El Niño and La Niña, respectively. The ENSO modulation of the QBO does not show up in the climate models with parameterized but temporally constant gravity wave sources. We show that the GISS E2.2 models can capture the observed ENSO modulation of the QBO period with a horizontal resolution of 2° by 2.5° and its gravity wave sources parameterized interactively.
Michael Sigmond, James Anstey, Vivek Arora, Ruth Digby, Nathan Gillett, Viatcheslav Kharin, William Merryfield, Catherine Reader, John Scinocca, Neil Swart, John Virgin, Carsten Abraham, Jason Cole, Nicolas Lambert, Woo-Sung Lee, Yongxiao Liang, Elizaveta Malinina, Landon Rieger, Knut von Salzen, Christian Seiler, Clint Seinen, Andrew Shao, Reinel Sospedra-Alfonso, Libo Wang, and Duo Yang
Geosci. Model Dev., 16, 6553–6591, https://doi.org/10.5194/gmd-16-6553-2023, https://doi.org/10.5194/gmd-16-6553-2023, 2023
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We present a new activity which aims to organize the analysis of biases in the Canadian Earth System model (CanESM) in a systematic manner. Results of this “Analysis for Development” (A4D) activity includes a new CanESM version, CanESM5.1, which features substantial improvements regarding the simulation of dust and stratospheric temperatures, a second CanESM5.1 variant with reduced climate sensitivity, and insights into potential avenues to reduce various other model biases.
Daniele Visioni, Ben Kravitz, Alan Robock, Simone Tilmes, Jim Haywood, Olivier Boucher, Mark Lawrence, Peter Irvine, Ulrike Niemeier, Lili Xia, Gabriel Chiodo, Chris Lennard, Shingo Watanabe, John C. Moore, and Helene Muri
Atmos. Chem. Phys., 23, 5149–5176, https://doi.org/10.5194/acp-23-5149-2023, https://doi.org/10.5194/acp-23-5149-2023, 2023
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Geoengineering indicates methods aiming to reduce the temperature of the planet by means of reflecting back a part of the incoming radiation before it reaches the surface or allowing more of the planetary radiation to escape into space. It aims to produce modelling experiments that are easy to reproduce and compare with different climate models, in order to understand the potential impacts of these techniques. Here we assess its past successes and failures and talk about its future.
Dillon Elsbury, Amy H. Butler, John R. Albers, Melissa L. Breeden, and Andrew O'Neil Langford
Atmos. Chem. Phys., 23, 5101–5117, https://doi.org/10.5194/acp-23-5101-2023, https://doi.org/10.5194/acp-23-5101-2023, 2023
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One of the global hotspots where stratosphere-to-troposphere transport (STT) of ozone takes place is over Pacific North America (PNA). However, we do not know how or if STT over PNA will change in response to climate change. Using climate model experiments forced with
worst-casescenario Representative Concentration Pathway 8.5 climate change, we find that changes in net chemical production and transport of ozone in the lower stratosphere increase STT of ozone over PNA in the future.
Khalil Karami, Rolando Garcia, Christoph Jacobi, Jadwiga H. Richter, and Simone Tilmes
Atmos. Chem. Phys., 23, 3799–3818, https://doi.org/10.5194/acp-23-3799-2023, https://doi.org/10.5194/acp-23-3799-2023, 2023
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Alongside mitigation and adaptation efforts, stratospheric aerosol intervention (SAI) is increasingly considered a third pillar to combat dangerous climate change. We investigate the teleconnection between the quasi-biennial oscillation in the equatorial stratosphere and the Arctic stratospheric polar vortex under a warmer climate and an SAI scenario. We show that the Holton–Tan relationship weakens under both scenarios and discuss the physical mechanisms responsible for such changes.
Ewa M. Bednarz, Daniele Visioni, Ben Kravitz, Andy Jones, James M. Haywood, Jadwiga Richter, Douglas G. MacMartin, and Peter Braesicke
Atmos. Chem. Phys., 23, 687–709, https://doi.org/10.5194/acp-23-687-2023, https://doi.org/10.5194/acp-23-687-2023, 2023
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Building on Part 1 of this two-part study, we demonstrate the role of biases in climatological circulation and specific aspects of model microphysics in driving the differences in simulated sulfate distributions amongst three Earth system models. We then characterize the simulated changes in stratospheric and free-tropospheric temperatures, ozone, water vapor, and large-scale circulation, elucidating the role of the above aspects in the surface responses discussed in Part 1.
John T. Fasullo and Jadwiga H. Richter
Atmos. Chem. Phys., 23, 163–182, https://doi.org/10.5194/acp-23-163-2023, https://doi.org/10.5194/acp-23-163-2023, 2023
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The continued high levels of anthropogenic greenhouse gas emissions increase the likelihood that key climate warming thresholds will be exceeded in the coming decades. Here we examine a recently proposed geoengineering approach using two recently produced climate model experiments. We find the associated latitudinal distribution of aerosol mass to exhibit substantial uncertainty, suggesting the need for significant flexibility in the location and amount of aerosol delivery, if implemented.
Chengzhu Zhang, Jean-Christophe Golaz, Ryan Forsyth, Tom Vo, Shaocheng Xie, Zeshawn Shaheen, Gerald L. Potter, Xylar S. Asay-Davis, Charles S. Zender, Wuyin Lin, Chih-Chieh Chen, Chris R. Terai, Salil Mahajan, Tian Zhou, Karthik Balaguru, Qi Tang, Cheng Tao, Yuying Zhang, Todd Emmenegger, Susannah Burrows, and Paul A. Ullrich
Geosci. Model Dev., 15, 9031–9056, https://doi.org/10.5194/gmd-15-9031-2022, https://doi.org/10.5194/gmd-15-9031-2022, 2022
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Earth system model (ESM) developers run automated analysis tools on data from candidate models to inform model development. This paper introduces a new Python package, E3SM Diags, that has been developed to support ESM development and use routinely in the development of DOE's Energy Exascale Earth System Model. This tool covers a set of essential diagnostics to evaluate the mean physical climate from simulations, as well as several process-oriented and phenomenon-based evaluation diagnostics.
Matthias Nützel, Sabine Brinkop, Martin Dameris, Hella Garny, Patrick Jöckel, Laura L. Pan, and Mijeong Park
Atmos. Chem. Phys., 22, 15659–15683, https://doi.org/10.5194/acp-22-15659-2022, https://doi.org/10.5194/acp-22-15659-2022, 2022
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During the Asian summer monsoon season, a large high-pressure system is present at levels close to the tropopause above Asia. We analyse how air masses are transported from surface levels to this high-pressure system, which shows distinct features from the surrounding air masses. To this end, we employ multiannual data from two complementary models that allow us to analyse the climatology as well as the interannual and intraseasonal variability of these transport pathways.
Jadwiga H. Richter, Daniele Visioni, Douglas G. MacMartin, David A. Bailey, Nan Rosenbloom, Brian Dobbins, Walker R. Lee, Mari Tye, and Jean-Francois Lamarque
Geosci. Model Dev., 15, 8221–8243, https://doi.org/10.5194/gmd-15-8221-2022, https://doi.org/10.5194/gmd-15-8221-2022, 2022
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Solar climate intervention using stratospheric aerosol injection is a proposed method of reducing global mean temperatures to reduce the worst consequences of climate change. We present a new modeling protocol aimed at simulating a plausible deployment of stratospheric aerosol injection and reproducibility of simulations using other Earth system models: Assessing Responses and Impacts of Solar climate intervention on the Earth system with stratospheric aerosol injection (ARISE-SAI).
Neal Butchart
Weather Clim. Dynam., 3, 1237–1272, https://doi.org/10.5194/wcd-3-1237-2022, https://doi.org/10.5194/wcd-3-1237-2022, 2022
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In recent years, it has emerged that there is an affinity between stratospheric variability and surface events. Waves from the troposphere interacting with the mean flow drive much of the variability in the polar vortex, sudden stratospheric warmings and tropical quasi-biennial oscillation. Here we review the historical evolution of established knowledge of the stratosphere's global structure and dynamical variability, along with recent advances and theories, and identify outstanding challenges.
John R. Albers, Amy H. Butler, Andrew O. Langford, Dillon Elsbury, and Melissa L. Breeden
Atmos. Chem. Phys., 22, 13035–13048, https://doi.org/10.5194/acp-22-13035-2022, https://doi.org/10.5194/acp-22-13035-2022, 2022
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Ozone transported from the stratosphere contributes to background ozone concentrations in the free troposphere and to surface ozone exceedance events that affect human health. The physical processes whereby the El Niño–Southern Oscillation (ENSO) modulates North American stratosphere-to-troposphere ozone transport during spring are documented, and the usefulness of ENSO for predicting ozone events that may cause exceedances in surface air quality standards are assessed.
Stephen G. Yeager, Nan Rosenbloom, Anne A. Glanville, Xian Wu, Isla Simpson, Hui Li, Maria J. Molina, Kristen Krumhardt, Samuel Mogen, Keith Lindsay, Danica Lombardozzi, Will Wieder, Who M. Kim, Jadwiga H. Richter, Matthew Long, Gokhan Danabasoglu, David Bailey, Marika Holland, Nicole Lovenduski, Warren G. Strand, and Teagan King
Geosci. Model Dev., 15, 6451–6493, https://doi.org/10.5194/gmd-15-6451-2022, https://doi.org/10.5194/gmd-15-6451-2022, 2022
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The Earth system changes over a range of time and space scales, and some of these changes are predictable in advance. Short-term weather forecasts are most familiar, but recent work has shown that it is possible to generate useful predictions several seasons or even a decade in advance. This study focuses on predictions over intermediate timescales (up to 24 months in advance) and shows that there is promising potential to forecast a variety of changes in the natural environment.
Mari R. Tye, Katherine Dagon, Maria J. Molina, Jadwiga H. Richter, Daniele Visioni, Ben Kravitz, and Simone Tilmes
Earth Syst. Dynam., 13, 1233–1257, https://doi.org/10.5194/esd-13-1233-2022, https://doi.org/10.5194/esd-13-1233-2022, 2022
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We examined the potential effect of stratospheric aerosol injection (SAI) on extreme temperature and precipitation. SAI may cause daytime temperatures to cool but nighttime to warm. Daytime cooling may occur in all seasons across the globe, with the largest decreases in summer. In contrast, nighttime warming may be greatest at high latitudes in winter. SAI may reduce the frequency and intensity of extreme rainfall. The combined changes may exacerbate drying over parts of the global south.
Zachary D. Lawrence, Marta Abalos, Blanca Ayarzagüena, David Barriopedro, Amy H. Butler, Natalia Calvo, Alvaro de la Cámara, Andrew Charlton-Perez, Daniela I. V. Domeisen, Etienne Dunn-Sigouin, Javier García-Serrano, Chaim I. Garfinkel, Neil P. Hindley, Liwei Jia, Martin Jucker, Alexey Y. Karpechko, Hera Kim, Andrea L. Lang, Simon H. Lee, Pu Lin, Marisol Osman, Froila M. Palmeiro, Judith Perlwitz, Inna Polichtchouk, Jadwiga H. Richter, Chen Schwartz, Seok-Woo Son, Irene Erner, Masakazu Taguchi, Nicholas L. Tyrrell, Corwin J. Wright, and Rachel W.-Y. Wu
Weather Clim. Dynam., 3, 977–1001, https://doi.org/10.5194/wcd-3-977-2022, https://doi.org/10.5194/wcd-3-977-2022, 2022
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Forecast models that are used to predict weather often struggle to represent the Earth’s stratosphere. This may impact their ability to predict surface weather weeks in advance, on subseasonal-to-seasonal (S2S) timescales. We use data from many S2S forecast systems to characterize and compare the stratospheric biases present in such forecast models. These models have many similar stratospheric biases, but they tend to be worse in systems with low model tops located within the stratosphere.
Jorge L. García-Franco, Lesley J. Gray, Scott Osprey, Robin Chadwick, and Zane Martin
Weather Clim. Dynam., 3, 825–844, https://doi.org/10.5194/wcd-3-825-2022, https://doi.org/10.5194/wcd-3-825-2022, 2022
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This paper establishes robust links between the stratospheric quasi-biennial oscillation (QBO) and several features of tropical climate. Robust precipitation responses, as well as changes to the Walker circulation, were found to be robustly linked to the variability in the lower stratosphere associated with the QBO using a 500-year simulation of a state-of-the-art climate model.
Peter Hitchcock, Amy Butler, Andrew Charlton-Perez, Chaim I. Garfinkel, Tim Stockdale, James Anstey, Dann Mitchell, Daniela I. V. Domeisen, Tongwen Wu, Yixiong Lu, Daniele Mastrangelo, Piero Malguzzi, Hai Lin, Ryan Muncaster, Bill Merryfield, Michael Sigmond, Baoqiang Xiang, Liwei Jia, Yu-Kyung Hyun, Jiyoung Oh, Damien Specq, Isla R. Simpson, Jadwiga H. Richter, Cory Barton, Jeff Knight, Eun-Pa Lim, and Harry Hendon
Geosci. Model Dev., 15, 5073–5092, https://doi.org/10.5194/gmd-15-5073-2022, https://doi.org/10.5194/gmd-15-5073-2022, 2022
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This paper describes an experimental protocol focused on sudden stratospheric warmings to be carried out by subseasonal forecast modeling centers. These will allow for inter-model comparisons of these major disruptions to the stratospheric polar vortex and their impacts on the near-surface flow. The protocol will lead to new insights into the contribution of the stratosphere to subseasonal forecast skill and new approaches to the dynamical attribution of extreme events.
Oscar Dimdore-Miles, Lesley Gray, Scott Osprey, Jon Robson, Rowan Sutton, and Bablu Sinha
Atmos. Chem. Phys., 22, 4867–4893, https://doi.org/10.5194/acp-22-4867-2022, https://doi.org/10.5194/acp-22-4867-2022, 2022
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This study examines interactions between variations in the strength of polar stratospheric winds and circulation in the North Atlantic in a climate model simulation. It finds that the Atlantic Meridional Overturning Circulation (AMOC) responds with oscillations to sets of consecutive Northern Hemisphere winters, which show all strong or all weak polar vortex conditions. The study also shows that a set of strong vortex winters in the 1990s contributed to the recent slowdown in the observed AMOC.
Jacopo Riboldi, Efi Rousi, Fabio D'Andrea, Gwendal Rivière, and François Lott
Weather Clim. Dynam., 3, 449–469, https://doi.org/10.5194/wcd-3-449-2022, https://doi.org/10.5194/wcd-3-449-2022, 2022
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A revisited space and time spectral decomposition allows us to determine which harmonics dominate the upper-tropospheric flow evolution over a given time period as well as their propagation. This approach is used to identify Rossby wave patterns with a circumglobal extent, affecting weather evolution over different Northern Hemisphere regions. The results cast light on the processes originating and supporting these wave patterns, advocating at the same time for the usefulness of the technique.
Ralf Döscher, Mario Acosta, Andrea Alessandri, Peter Anthoni, Thomas Arsouze, Tommi Bergman, Raffaele Bernardello, Souhail Boussetta, Louis-Philippe Caron, Glenn Carver, Miguel Castrillo, Franco Catalano, Ivana Cvijanovic, Paolo Davini, Evelien Dekker, Francisco J. Doblas-Reyes, David Docquier, Pablo Echevarria, Uwe Fladrich, Ramon Fuentes-Franco, Matthias Gröger, Jost v. Hardenberg, Jenny Hieronymus, M. Pasha Karami, Jukka-Pekka Keskinen, Torben Koenigk, Risto Makkonen, François Massonnet, Martin Ménégoz, Paul A. Miller, Eduardo Moreno-Chamarro, Lars Nieradzik, Twan van Noije, Paul Nolan, Declan O'Donnell, Pirkka Ollinaho, Gijs van den Oord, Pablo Ortega, Oriol Tintó Prims, Arthur Ramos, Thomas Reerink, Clement Rousset, Yohan Ruprich-Robert, Philippe Le Sager, Torben Schmith, Roland Schrödner, Federico Serva, Valentina Sicardi, Marianne Sloth Madsen, Benjamin Smith, Tian Tian, Etienne Tourigny, Petteri Uotila, Martin Vancoppenolle, Shiyu Wang, David Wårlind, Ulrika Willén, Klaus Wyser, Shuting Yang, Xavier Yepes-Arbós, and Qiong Zhang
Geosci. Model Dev., 15, 2973–3020, https://doi.org/10.5194/gmd-15-2973-2022, https://doi.org/10.5194/gmd-15-2973-2022, 2022
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The Earth system model EC-Earth3 is documented here. Key performance metrics show physical behavior and biases well within the frame known from recent models. With improved physical and dynamic features, new ESM components, community tools, and largely improved physical performance compared to the CMIP5 version, EC-Earth3 represents a clear step forward for the only European community ESM. We demonstrate here that EC-Earth3 is suited for a range of tasks in CMIP6 and beyond.
Dai Koshin, Kaoru Sato, Masashi Kohma, and Shingo Watanabe
Geosci. Model Dev., 15, 2293–2307, https://doi.org/10.5194/gmd-15-2293-2022, https://doi.org/10.5194/gmd-15-2293-2022, 2022
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The 4D ensemble Kalman filter data assimilation system for the whole neutral atmosphere has been updated. The update includes the introduction of a filter to reduce the generation of spurious waves, change in the order of horizontal diffusion of the forecast model to reproduce more realistic tidal amplitudes, and use of additional satellite observations. As a result, the analysis performance has been greatly improved, even for disturbances with periods of less than 1 d.
Adam A. Scaife, Mark P. Baldwin, Amy H. Butler, Andrew J. Charlton-Perez, Daniela I. V. Domeisen, Chaim I. Garfinkel, Steven C. Hardiman, Peter Haynes, Alexey Yu Karpechko, Eun-Pa Lim, Shunsuke Noguchi, Judith Perlwitz, Lorenzo Polvani, Jadwiga H. Richter, John Scinocca, Michael Sigmond, Theodore G. Shepherd, Seok-Woo Son, and David W. J. Thompson
Atmos. Chem. Phys., 22, 2601–2623, https://doi.org/10.5194/acp-22-2601-2022, https://doi.org/10.5194/acp-22-2601-2022, 2022
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Great progress has been made in computer modelling and simulation of the whole climate system, including the stratosphere. Since the late 20th century we also gained a much clearer understanding of how the stratosphere interacts with the lower atmosphere. The latest generation of numerical prediction systems now explicitly represents the stratosphere and its interaction with surface climate, and here we review its role in long-range predictions and projections from weeks to decades ahead.
Daniele Visioni, Simone Tilmes, Charles Bardeen, Michael Mills, Douglas G. MacMartin, Ben Kravitz, and Jadwiga H. Richter
Atmos. Chem. Phys., 22, 1739–1756, https://doi.org/10.5194/acp-22-1739-2022, https://doi.org/10.5194/acp-22-1739-2022, 2022
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Aerosols are simulated in a simplified way in climate models: in the model analyzed here, they are represented in every grid as described by three simple logarithmic distributions, mixing all different species together. The size can evolve when new particles are formed, particles merge together to create a larger one or particles are deposited to the surface. This approximation normally works fairly well. Here we show however that when large amounts of sulfate are simulated, there are problems.
Sheena Loeffel, Roland Eichinger, Hella Garny, Thomas Reddmann, Frauke Fritsch, Stefan Versick, Gabriele Stiller, and Florian Haenel
Atmos. Chem. Phys., 22, 1175–1193, https://doi.org/10.5194/acp-22-1175-2022, https://doi.org/10.5194/acp-22-1175-2022, 2022
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SF6-derived trends of stratospheric AoA from observations and model simulations disagree in sign. SF6 experiences chemical degradation, which we explicitly integrate in a global climate model. In our simulations, the AoA trend changes sign when SF6 sinks are considered; thus, the process has the potential to reconcile simulated with observed AoA trends. We show that the positive AoA trend is due to the SF6 sinks themselves and provide a first approach for a correction to account for SF6 loss.
John P. McCormack, V. Lynn Harvey, Cora E. Randall, Nicholas Pedatella, Dai Koshin, Kaoru Sato, Lawrence Coy, Shingo Watanabe, Fabrizio Sassi, and Laura A. Holt
Atmos. Chem. Phys., 21, 17577–17605, https://doi.org/10.5194/acp-21-17577-2021, https://doi.org/10.5194/acp-21-17577-2021, 2021
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In order to have confidence in atmospheric predictions, it is important to know how well different numerical model simulations of the Earth’s atmosphere agree with one another. This work compares four different data assimilation models that extend to or beyond the mesosphere. Results shown here demonstrate that while the models are in close agreement below ~50 km, large differences arise at higher altitudes in the mesosphere and lower thermosphere that will need to be reconciled in the future.
Lee T. Murray, Eric M. Leibensperger, Clara Orbe, Loretta J. Mickley, and Melissa Sulprizio
Geosci. Model Dev., 14, 5789–5823, https://doi.org/10.5194/gmd-14-5789-2021, https://doi.org/10.5194/gmd-14-5789-2021, 2021
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Chemical-transport models are tools used to study air pollution and inform public policy. However, they are limited by the availability of archived meteorology. Here, we describe how the GEOS-Chem chemical-transport model may now be driven by meteorology archived from a state-of-the-art general circulation model for past and future climates, allowing it to be used to explore the impact of climate change on air pollution and atmospheric composition.
Marta Abalos, Natalia Calvo, Samuel Benito-Barca, Hella Garny, Steven C. Hardiman, Pu Lin, Martin B. Andrews, Neal Butchart, Rolando Garcia, Clara Orbe, David Saint-Martin, Shingo Watanabe, and Kohei Yoshida
Atmos. Chem. Phys., 21, 13571–13591, https://doi.org/10.5194/acp-21-13571-2021, https://doi.org/10.5194/acp-21-13571-2021, 2021
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The stratospheric Brewer–Dobson circulation (BDC), responsible for transporting mass, tracers and heat globally in the stratosphere, is evaluated in a set of state-of-the-art climate models. The acceleration of the BDC in response to increasing greenhouse gases is most robust in the lower stratosphere. At higher levels, the well-known inconsistency between model and observational BDC trends can be partly reconciled by accounting for limited sampling and large uncertainties in the observations.
Cited articles
Alexander, M. J., Geller, M., McLandress, C., Polavarapu, S., Preusse, P., Sassi, F., Sato, K., Eckermann, S. D., Ern, M., Hertzog, A., Kawatani, Y., Pulido, M., Semeniuk, K., Shapiro, I., Shephard, G. G., Shiotani, M., Sofieva, V. F., and Wang, L.: Recent developments in gravity-wave effects in climate models and the global distribution of gravity-wave momentum flux from observations and models, Q. J. Roy. Meteor. Soc., 136, 1103–1124, https://doi.org/10.1002/qj.637, 2010.
Andrews, D. G., Holton, J. R., and Leovy, C. B.: Middle Atmosphere Dynamics, Academic Press, 489 pp., ISBN 978-0120585762, 1987.
Anstey, J. A. and Shepherd, T.: High-latitude influence of the quasi-biennial oscillation, Q. J. Roy. Meteor. Soc., 140, 1–21, https://doi.org/10.1002/qj.2132, 2014.
Anstey, J. A., Simpson, I. R., Richter, J. H., Naoe, H., Taguchi, M., Serva, F., Gray, L. J., Butchart, N., Hamilton, K., Osprey, S., Bellprat, O., Braesicke, P., Bushell, A. C., Cagnazzo, C., Chen, C.-C., Chun, H.-Y., Garcia, R. R., Holt, L., Kawatani, Y., Kerzenmacher, T., Kim, Y.-H., Lott, F., McLandress, C., Scinocca, J., Stockdale, T. N., Versick, S., Watanabe, S., and Yoshida, K.: Teleconnections of the quasi-biennial oscillation in a multi-model ensemble of QBO-resolving models, Q. J. Roy. Meteor. Soc., https://doi.org/10.1002/qj.4048, 2021.
Anstey, J. A., Butchart, N., Hamilton, K., and Osprey, M.: The SPARC Quasi-Biennial Oscillation initiative, Q. J. Roy. Meteor. Soc., 148, 1455–1458, https://doi.org/10.1002/qj.3820, 2022a.
Anstey, J. A., Osprey, S. M., Alexander, J., Baldwin, M. P., Butchart, N., Gray, L., Kawatani, Y., Newman, P. A., and Richter, J. H.: The Quasi-Biennial Oscillation: Impacts, processes, and projections, Nat. Rev. Earth Environ., https://doi.org/10.1038/s43017-022-00323-7, 2022b.
Baldwin, M. P. and Dunkerton, T. J.: Stratospheric harbingers of anomalous weather regimes, Science, 294, 581–584, 2001.
Baldwin, M. P., Gray, L. J., Dunkerton, T. J., Hamilton, K., Haynes, P. H., Randel, W. J., Holton, J. R., Alexander, M. J., Hirota, I., Horinouchi, T., Jones, D. B. A., Kinnersley, J. S., Marquardt, C., Sato, K., and Takahashi, M.: The Quasi-Biennial Oscillation, Rev. Geophys., 39, 179–229, 2001.
Bushell, A. C., Anstey, J. A., Butchart, N., Kawatani, Y., Osprey, S. M., Richter, J. H., Serva, F., Braesicke, P., Cagnazzo, C., Chen, C.-C., Chun, H.-Y., Garcia, R. R., Gray, L. J., Hamilton, K., Kerzenmacher, T., Kim, Y.-H., Lott, F., McLandress, C., Naoe, H., Scinocca, J., Stockdale, T. N., Watanabe, S., Yoshida, K., and Yukimoto, S.: Evaluation of the Quasi-Biennial Oscillation in global climate models for the SPARC QBO-initiative, Q. J. Roy. Meteor. Soc., https://doi.org/10.1002/qj.3765, 2020.
Butchart, N., Anstey, J. A., Hamilton, K., Osprey, S., McLandress, C., Bushell, A. C., Kawatani, Y., Kim, Y.-H., Lott, F., Scinocca, J., Stockdale, T. N., Andrews, M., Bellprat, O., Braesicke, P., Cagnazzo, C., Chen, C.-C., Chun, H.-Y., Dobrynin, M., Garcia, R. R., Garcia-Serrano, J., Gray, L. J., Holt, L., Kerzenmacher, T., Naoe, H., Pohlmann, H., Richter, J. H., Scaife, A. A., Schenzinger, V., Serva, F., Versick, S., Watanabe, S., Yoshida, K., and Yukimoto, S.: Overview of experiment design and comparison of models participating in phase 1 of the SPARC Quasi-Biennial Oscillation initiative (QBOi), Geosci. Model Dev., 11, 1009–1032, https://doi.org/10.5194/gmd-11-1009-2018, 2018.
Butchart, N., Anstey, J. A., Kawatani, Y., Osprey, S. M., Richter, J. H., and Wu, T.: QBO changes in CMIP6 climate projections, Geophys. Res. Lett., https://doi.org/10.1029/2019GL086903, 2020.
Calvo, N., Garcia, R. R., Randel, W. J., and Marsh, D. R.: Dynamical mechanism for the increase in tropical upwelling in the lowermost tropical stratosphere during warm ENSO events, J. Atmos. Sci., 67, 2331–2340, https://doi.org/10.1175/2010JAS3433.1, 2010.
Coy, L., Newman, P. A., Strahan, S., and Pawson, S.: Seasonal variation of the Quasi-Biennial Oscillation descent, J. Geophys. Res.-Atmos., 125, e2020JD033077, https://doi.org/10.1029/2020JD033077, 2020.
DallaSanta, K., Orbe, C., Rind, D., Nazarenko, L., and Jonas, J.: Dynamical and trace gas responses of the quasi-biennial oscillation to increased CO2, J. Geophys. Res.-Atmos. 126, e2020JD034151, https://doi.org/10.1029/2020JD034151, 2021., 2021.
Doty, B. E. and Kinter, III, J. L.: Geophysical Data Analysis and Visualization Using the Grid Analysis and Display System, National Aeronautics and Space Administration, Washington, DC (United States), https://ntrs.nasa.gov/citations/19960022591 (last access: 1 March 2024) [code], 1995.
Dunkerton, T. J.: Modification of stratospheric circulation by trace constituent changes?, J. Geophys. Res., 88, 10831–10836, 1983.
Dunkerton, T. J.: The role of gravity waves in the quasi-biennial oscillation, J. Geophys. Res.-Atmos., 102, 26053–26076, 1997.
Dunkerton, T. J. and Delisi, D. P.: Climatology of the equatorial lower stratosphere, J. Atmos. Sci., 42, 376–396, https://doi.org/10.1175/1520-0469(1985)042<0376:COTELS>2.0.CO;2, 1985.
Elsbury, D., Serva, F., Caron, J. M., Back, S.-Y., Orbe, C., Richter, J. H., Anstey, J. A., Butchart, N., Chen, C.-C., García-Serrano, J., Glanville, A., Kawatani, Y., Kerzenmacher, T., Lott, F., Naoe, H., Osprey, S., Palmeiro, F. M., Son, S.-W., Taguchi, M., Versick, S., Watanabe, S., and Yoshida, K.: QBOi El Niño Southern Oscillation experiments: Assessing relationships between ENSO, MJO, and QBO, EGUsphere [preprint], https://doi.org/10.5194/egusphere-2024-3950, 2025.
Evan, S., Alexander, M. J., and Duhia, J.: Model study of intermediate-scale tropical inertia-gravity waves and comparison to TWP-ICE campaign observations, J. Atmos. Sci., 69, 591–610, https://doi.org/10.1175/JAS-D-11-051.1, 2012.
Geller, M. A., Shen, W., Zhang, M., and Tan, W.-W.: Calculations of the stratospheric quasi-biennial oscillation for time-varying wave forcing, J. Atmos. Sci., 54, 883–894, https://doi.org/10.1175/1520-0469(1997)054<0883:COTSQB>2.0.CO;2, 1997.
Geller, M. A., Zhou, T., and Yuan, W.: The QBO, gravity waves forced by tropical convection, and ENSO, J. Geophys. Res.-Atmos., 121, 8886–8895, https://doi.org/10.1002/2015JD024125, 2016.
GFD Dennou Club: GFD Dennou Club codes, https://dennou-h.gfd-dennou.org/index.html.en (last access: 1 March 2024) [code], 2024
Giorgetta, M. A., Manzini, E., Roeckner, E., Esch, M., and Bengtsson, L.: Climatology and forcing of the quasi-biennial oscillation in the MAECHAM5 model. J. Climate, 19, 2882–3901, https://doi.org/10.1175/JCLI3830.1, 2002.
Hamilton, K.: On the quasi-decadal modulation of the stratospheric QBO period, J. Climate, 15, 2562–2565, https://doi.org/10.1175/1520-0442(2002)015<2562:OTQDMO>2.0.CO;2, 2002.
Hamilton, K., Wilson, R. J., and Hemler, R.: Middle atmosphere simulated with high vertical and horizontal resolution versions of a GCM: Improvement in the cold pole bias and generation of a QBO-like oscillation in the tropics, J. Atmos. Sci., 56, 3829–3846, 1999.
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz-Sabater, J., Nicolas, J., Peubey, C., Radu, R., Schepers, D., Simmons, A., Soci, C., Abdalla, S., Abellan, X., Balsamo, G., Bechtold, P., Biavati, G., Bidlot, J., Bonavita, M., De Chiara, G., Dahlgren, P., Dee, D., Diamantakis, M., Dragani, R., Flemming, J., Forbes, R., Fuentes, M., Geer, A., Haimberger, L., Healy, S., Hogan, R. J., Hólm, E., Janisková, M., Keeley, S., Laloyaux, P., Lopez, P., Lupu, C., Radnoti, G., Rosnay, P. de, Rozum, I., Vamborg, F., Villaume, S., and Thépaut, J.-N.: The ERA5 global reanalysis, Q. J. Roy. Meteor. Soc., 146, 1999–2049, https://doi.org/10.1002/qj.3803, 2020.
Hines, C. O.: Doppler-spread parameterization of gravity-wave momentum deposition in the middle atmosphere. part 2: Broad and quasi monochromatic spectra, and implementation, J. Atmos. Sol.-Terr. Phy., 59, 387–400, 1997.
Holt, L., Lott, F., Garcia, R., Kiladis, G. N., Anstey, J. A., Braesicke, P., Bushell, A. C., Butchart, N., Cagnazzo, C., Chen, C.-C., Chun, H.-Y., Kawatani, Y., Kerzenmacher, T., Kim, Y.-H., McLandress, C., Naoe, H., Osprey, S., Richter, J. H., Scaife, A. A., Scinocca, J., Serva, F., Versick, S., Watanabe, S., and Yukimoto, S.: An evaluation of tropical waves and wave forcing of the QBO in the QBOi models, Q. J. Roy. Meteor. Soc., https://doi.org/10.1002/qj.3827, 2020.
Japan Meteorological Agency: El Niño monitoring and outlook (including monitoring indices), http://ds.data.jma.go.jp/tcc/tcc/products/elnino/index.html (last access: 1 March 2024) [data set], 2024.
Kane, R. P.: Comparison of stratospheric zonal winds and El Niño–Southern Oscillation in recent decades, Int. J. Climatol., 24, 525–532, 2004.
Karlsruhe Institute of Technology (KIT): QBO Data Series at ATMO Hub [data set], https://www.atmohub.kit.edu/english/807.php (last access: 1 March 2024), 2025.
Kawatani, Y. and Hamilton, K.: Weakened stratospheric Quasi-biennial Oscillation driven by increased tropical mean upwelling, Nature, 497, 478–481, https://doi.org/10.1038/nature12140, 2013.
Kawatani, Y., Tsuji, K., and Takahashi, M.: Zonally non-uniform distribution of equatorial gravity waves in an atmospheric General Circulation Model, Geophys. Res. Lett., 32, L23815, https://doi.org/10.1029/2005GL024068, 2005.
Kawatani, Y., Takahashi, M., Sato, K., Alexander, S. P., and Tsuda, T.: Global distribution of atmospheric waves in the equatorial upper troposphere and lower stratosphere: AGCM simulation of sources and propagation, J. Geophys. Res., 114, D01102, https://doi.org/10.1029/2008JD010374, 2009.
Kawatani, Y., Sato, K., Dunkerton, T. J., Watanabe, S., Miyahara, S., and Takahashi, M.: The roles of equatorial trapped waves and internal inertia-gravity waves in driving the Quasi-biennial Oscillation. Part I: Zonal mean wave forcing, J. Atmos. Sci., 67, 963–980, https://doi.org/10.1175/2009JAS3222.1, 2010a.
Kawatani, Y., Sato, K., Dunkerton, T. J., Watanabe, S., Miyahara, S., and Takahashi, M.: The roles of equatorial trapped waves and internal inertia-gravity waves in driving the Quasi-biennial Oscillation. Part II: Three-dimensional distribution of wave forcing, J. Atmos. Sci., 67, 981–997, https://doi.org/10.1175/2009JAS3223.1, 2010b.
Kawatani, Y., Hamilton, K., and Watanabe, S.: The Quasi-Biennial Oscillation in a doubled CO2 climate, J. Atmos. Sci., 68, 265–283, https://doi.org/10.1175/2010JAS3623.1, 2011.
Kawatani, Y., Hamilton, K., and Noda, A.: The effects of changes in sea surface temperature and CO2 concentration on the quasi-biennial oscillation, J. Atmos. Sci., 69, 1734–1749, https://doi.org/10.1175/JAS-D-11-0265.1, 2012.
Kawatani, Y., Hamilton, K., Sato, K., Dunkerton, T. J., Watanabe, S., and Kikuchi, K.: ENSO modulation of the QBO: Results from MIROC models with and without non-orographic gravity wave parameterization, J. Atmos. Sci., 76, 3893–3917, https://doi.org/10.1175/JAS-D-19-0163.1, 2019.
Kidston, J., Scaife, A. A., Hardiman, S. C., Mitchell, D. M., Butchart, N., Baldwin, M. P., and Gray, L. J.: Stratospheric influence on tropospheric jet streams, storm tracks and surface weather, Nat. Geosci., 8, 433–440, https://doi.org/10.1038/ngeo2424, 2015.
Lee, H.-K., Chun, H.-Y., Richter, J. H., Simpson, I. R., and Garcia, R. R.: Contributions of parameterized gravity waves and resolved equatorial waves to the QBO period in a future climate of CESM2, J. Geophys. Res.-Atmos., 129, e2024JD040744, https://doi.org/10.1029/2024JD040744, 2024.
Lindzen, R. S. and Holton, J. R.: A theory of the Quasibiennial Oscillation, J. Atmos. Sci., 25, 1095–1107, 1968.
Lott, F., Guez, L., and Maury, P.: A stochastic parameterization of non-orographic gravity waves: Formalism and impact on the equatorial stratosphere, Geophys. Res. Lett., 39, L06807, https://doi.org/10.1029/2012GL051001, 2012.
Lott, F., Rani, R., McLandress, C., Podglajen, A., Bushesll, A., Bramberger, M., Lee, H.-K., Alexander, J., Anstey, J., Chun, H.-Y., Herzog, A., Butchart, N., Kim, Y.-H., Kawatani, Y., Legras, B., Manzini, E., Naoe, H., Osprey, S., Plougonven, R., Pohlmann, H., Richter, J. H., Scinocca, J., Garcia-Serrano, J., Serva, F., Stockdale, F., Versick, S., Watanabe, S., and Yoshida, K.: Comparison between non orographic gravity wave parameterizations used in QBOi models and Strateole 2 constant level balloons, Q. J. Roy. Meteor. Soc., 150, 3721–3736, https://doi.org/10.1002/qj.4793, 2024.
Lu, J., Chen, G., and Frierson, D. M. W.: Response of the zonal mean atmospheric circulation to El Niño versus global warming, J. Climate, 21, 5835–5851, https://doi.org/10.1175/2008JCLI2200.1, 2008.
Naoe, H. and Yoshida, K.: Influence of quasi-biennial oscillation on the boreal winter extratropical stratosphere in QBOi experiments, Q. J. Roy. Meteor. Soc., 145, 2755–2771, https://doi.org/10.1002/qj.3591, 2019.
Naujokat, B.: An update of the observed Quasibiennial Oscillation of the stratospheric zonal winds over the tropics, J. Atmos. Sci., 43, 1873–1877, https://doi.org/10.1175/1520-0469(1986)043<1873:AUOTOQ>2.0.CO;2, 1986.
OpenAI: ChatGPT, https://chat.openai.com/, last access: 9 July 2025.
Pahlavan, H. A., Wallace, J. M., Fu, Q., and Kiladis, G. N.: Revisiting the Quasi-Biennial Oscillation as seen in ERA5. Part II: Evaluation of waves and wave forcing, J. Atmos. Sci., 78, 693–707, https://doi.org/10.1175/JAS-D-20-0249.1, 2021.
Palmeiro, F. M., García-Serrano, J., Fuentes-Franco, R., Davini, P., Acosta, M., and Doblas-Reyes, F. J.: Boreal winter stratospheric climatology in EC-EARTH: CMIP6 version, Clim. Dynam., 59, 1321–1344, https://doi.org/10.1007/s00382-022-06368-0, 2022.
Quiroz, R. S.: Period modulation of the stratospheric Quasibiennial Oscillation, Mon. Weather Rev., 109, 665–674, https://doi.org/10.1175/1520-0493(1981)109<0665:PMOTSQ>2.0.CO;2, 1981.
Randel, W. J., Garcia, R. R., Calvo, N., and Marsh, D.: ENSO influence on zonal mean temperature and ozone in the tropical lower stratosphere, Geophys. Res. Lett., 36, L15822, https://doi.org/10.1029/2009GL039343, 2009.
Richter, J. H., Butchart, N., Kawatani, Y., Bushell, A. C., Holt, L., Serva, F., Anstey, J. A., Simpson, I. R., Osprey, S. M., Hamilton, K., Braesicke, P., Cagnazzo, C., Chen, C.-C., Garcia, R. R., Gray, L. J., Kerzenmacher, T., Lott, F., McLandress, C., Naoe, H., Scinocca, J., Stockdale, T. N., Versick, S., Watanabe, S., Yoshida, K., and Yukimoto, S.: Response of the Quasi-Biennial Oscillation to a warming climate in global climate models, Q. J. Roy. Meteor. Soc., https://doi.org/10.1002/qj.3749, 2020.
Richter J. H., Sassi, F., and Garcia, R. R.: Toward a Physically Based Gravity Wave Source Parameterization in a General Circulation Model, J. Atmos. Sci., 67, 136–156, https://doi.org/10.1175/2009JAS3112.1, 2010.
Rind, D., Lerner, J., Jonas, J., and McLinden, C.: The effects of resolution and model physics on tracer transports in the NASA Goddard Institute for Space Studies general circulation models, J. Geophys. Res., 112, D09315, https://doi.org/10.1029/2006JD007476, 2007.
Rind, D., Jonas, J., Kelley, M., Lacis, A., Russell, G., Schmidt, G. A., and Ruedy, R.: GISS Model E2.2: A climate model optimized for the middle atmosphere – model structure, climatology, variability, and climate sensitivity, J. Geophys. Res.-Atmos., 125, e2019JD032204, https://doi.org/10.1029/2019JD032204, 2020.
Salby, M. and Callaghan, P.: Connection between the solar cycle and the QBO: The missing link, J. Climate, 13, 2652–2662, https://doi.org/10.1175/1520-0442(1999)012<2652:CBTSCA>2.0.CO;2, 2000.
Schirber, S.: Influence of ENSO on the QBO: Results from an ensemble of idealized simulations, J. Geophys. Res., 120, 1109–1122, https://doi.org/10.1002/2014JD022460, 2015.
Scinocca, J. F.: An accurate spectral nonorographic gravity wave drag parameterization for general circulation models, J. Atmos. Sci., 60, 667–682., 2003.
Serva, F.: Transformed Eulerian mean data from the ERA5 reanalysis (daily means) (0.1.1), Zenodo [data set], https://doi.org/10.5281/zenodo.7081436, 2022.
Serva, F., Cagnazzo, C., Christiansen, B., and Yang, S.: The influence of ENSO events on the stratospheric QBO in a multi-model ensemble, Clim. Dynam., 54, 2561–2575, https://doi.org/10.1007/s00382-020-05131-7, 2020.
Serva, F., Christiansen, B., Davini, P., von Hardenberg, J., van den Oord, G., Reerink, T. J., Wyser, K., and Yang, S.: Changes in stratospheric dynamics simulated by the EC-Earth model from CMIP5 to CMIP6, J. Adv. Model. Earth Syst., https://doi.org/10.1029/2023MS003756, 2024.
Simpson, I. R., Sigmond, M., and Shepherd, T. G.: Dynamics of the lower stratospheric circulation response to ENSO, J. Atmos. Sci., 68, 2537–2556, https://doi.org/10.1175/JAS-D-11-05.1, 2011.
Stockdale, T. N., Kim, Y.-H., Anstey, J. A., Palmeiro, F. M., Butchart, N., Scaife, A. A., Andrews, M., Bushell, A. C., Dobrynin, M., Garcia-Serrano, J., Hamilton, K., Kawatani, Y., Lott, F., McLandress, C., Naoe, H., Osprey, S. M., Pohlmann, H., Scinocca, J., Watanabe, S., Yoshida, K., and Yukimoto, S : Prediction of the quasi-biennial oscillation with a multi-model ensemble of QBO-resolving models, Q. J. Roy. Meteor. Soc., https://doi.org/10.1002/qj.3919, 2020.
Taguchi, M.: Observed connection of the stratospheric quasi-biennial oscillation with El Niño–Southern Oscillation in radiosonde data, J. Geophys. Res., 115, D18120, https://doi.org/10.1029/2010JD014325, 2010.
Trenberth, K. E., Branstator, G. W., Karoly, D., Kumar, A., Lau N.-C., and Ropelewski, C.: Progress during TOGA in understanding and modeling global teleconnections associated with tropical sea surface temperatures, J. Geophys. Res.-Atmos., 103, 14167–14510, https://doi.org/10.1029/97JC01444, 1998.
Vecchi, G. A. and Soden, B. J.: Global warming and the weakening of the tropical circulation, J. Climate, 20, 4316–4340, https://doi.org/10.1175/JCLI4258.1, 2007.
Watanabe, S. and Kawatani, Y.: Sensitivity of the QBO to mean tropical upwelling under a changing climate simulated by an Earth system model, J. Meteorol. Soc. Jpn., 90A, 351–360, https://doi.org/10.2151/jmsj.2012-A20, 2012.
Watanabe, S., Kawatani, Y., Tomikawa, Y., Miyazaki, K., Takahashi, M., and Sato, K.: General aspects of a T213L256 middle atmosphere general circulation model, J. Geophys. Res., 113, D12110, https://doi.org/10.1029/2008JD010026, 2008.
Xie, P. and Arkin, P. A.: Global Precipitation: A 17-year monthly analysis based on gauge observations, satellite estimates, and numerical model outputs, B. Am. Meteorol. Soc., 78, 2539–2558, https://doi.org/10.1175/1520-0477(1997)078<2539:GPAYMA>2.0.CO;2, 1997.
Yoo, C. and Son, S.-W.: Modulation of the boreal wintertime Madden-Julian oscillation by the stratospheric quasi-biennial oscillation, Geophys. Res. Lett., 43, 1392–1398, https://doi.org/10.1002/2016GL067762, 2016.
Yukimoto, S., Kawai, H., Koshiro, T., Oshima, N., Yoshida, K., Urakawa, S., Tsujino, H., Deushi, M., Tanaka, T., Hosaka, M., Yabu, S., Yoshimura, H., Shindo, E., Mizuta, R., Obata, A., Adachi, Y., and Ishii, M.: The Meteorological Research Institute Earth System Model Version 2.0, MRI-ESM2.0: Description and basic evaluation of the physical component. J. Meteorol. Soc. Jpn., 97, 931–965, https://doi.org/10.2151/jmsj.2019-051, 2019.
Yuan, W., Geller, M. A., and Love, P. T.: ENSO influence on QBO modulations of the tropical tropopause, Q. J. Roy. Meteor. Soc., 140, 1670–1676, https://doi.org/10.1002/qj.2247, 2014.
Zhou, T., DallaSanta, K. J., Orbe, C., Rind, D. H., Jonas, J. A., Nazarenko, L., Schmidt, G. A., and Russell, G.: Exploring the ENSO modulation of the QBO periods with GISS E2.2 models, Atmos. Chem. Phys., 24, 509–532, https://doi.org/10.5194/acp-24-509-2024, 2024.
Short summary
The Quasi-Biennial Oscillation (QBO) of the tropical stratospheric mean winds has been relatively steady over the 7 decades it has been observed, but there are always cycle-to-cycle variations. This study used several global atmospheric models to investigate systematic modulation of the QBO by the El Niño/La Niña cycle. All models simulated shorter periods during El Niño, in agreement with observations. By contrast, the models disagreed even on the sign of the El Niño effect on QBO amplitude.
The Quasi-Biennial Oscillation (QBO) of the tropical stratospheric mean winds has been...
