Articles | Volume 7, issue 3
https://doi.org/10.5194/wcd-7-1797-2026
© Author(s) 2026. 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-7-1797-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
16 Sep 2026
Research article |
| 16 Sep 2026
| 16 Sep 2026
Extratropical teleconnections in a multi-model ensemble nudged towards the observed QBO
Martin B. Andrews
CORRESPONDING AUTHOR
Met Office Hadley Centre (MOHC), Exeter, UK
Neal Butchart
Met Office Hadley Centre (MOHC), Exeter, UK
James A. Anstey
Canadian Centre for Climate Modelling and Analysis, Environment and Climate Change Canada, Victoria, British Columbia, Canada
Ewa Bednarz
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado Boulder, Boulder, CO, USA
NOAA Chemical Sciences Laboratory (CSL), Boulder, CO, USA
Dillon Elsbury
Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado Boulder, Boulder, CO, USA
NOAA Chemical Sciences Laboratory (CSL), Boulder, CO, USA
Jorge L. García-Franco
Lamont Doherty Earth Observatory, Columbia University, Palisades, NY, USA
Escuela Nacional de Ciencias de la Tierra, Universidad Nacional Autónoma de México, Mexico City, Mexico
Vinay Kumar
Radio and Atmospheric Physics Lab, Rajdhani College, University of Delhi, New Delhi, India
Froila M. Palmeiro
CMCC Foundation - Euro-Mediterranean Center on Climate Change, Bologna, Italy
Natasha E. Trencham
Department of Applied Physics and Applied Mathematics, Columbia University, New York, NY, USA
Kohei Yoshida
Meteorological Research Institute, Japan Meteorological Agency, Tsukuba, Japan
Zhaoyang Chai
Earth System Numerical Simulation Science Center, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
Dong-Chan Hong
School of Earth and Environmental Sciences, Seoul National University, Seoul, Republic of Korea
Kai Huang
Department of Atmospheric, Oceanic and Earth Sciences, George Mason University, Fairfax, VA, USA
Aleena M. Jaison
Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, UK
Yoshio Kawatani
Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
Jeff R. Knight
Met Office Hadley Centre (MOHC), Exeter, UK
Pu Lin
Atmospheric and Oceanic Sciences, Princeton University, Princeton, NJ, USA
Geophysical Fluid Dynamics Laboratory (NOAA), Princeton, NJ, USA
François Lott
Laboratoire de Météorologie Dynamique (LMD)/IPSL, Paris, France
Yixiong Lu
Earth System Modeling and Prediction Centre, China Meteorological Administration, Beijing, China
Hiroaki Naoe
Meteorological Research Institute, Japan Meteorological Agency, Tsukuba, Japan
Scott M. Osprey
National Centre for Atmospheric Science, University of Oxford, Oxford, UK
Atmospheric, Oceanic and Planetary Physics, University of Oxford, Oxford, UK
Jadwiga H. Richter
Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO, USA
Federico Serva
Consiglio Nazionale delle Ricerche, Institute of Marine Sciences (CNR-ISMAR), Rome, Italy
Seok-Woo Son
School of Earth and Environmental Sciences, Seoul National University, Seoul, Republic of Korea
Lawrence Livermore National Laboratory, Livermore, CA, USA
Shingo Watanabe
Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan
Advanced Institute for Marine Ecosystem Change (WPI-AIMEC), Tohoku University, Sendai, Japan
Jinbo Xie
Lawrence Livermore National Laboratory, Livermore, CA, USA
High Meadows Environmental Institute (HMEI), Princeton University, Princeton, NJ, USA
Related authors
Reinhard K. H. Schiemann, Grenville Lister, Rosalyn Hatcher, Dan Hodson, Bryan Lawrence, Len Shaffrey, Jeff Cole, Andrea Dittus, Jenny Mecking, Jon Robson, Simon Wilson, Yevgeny Aksenov, Adam T. Blaker, Ben Harvey, Oscar Martínez-Alvarado, Annette Osprey, Stephanie Rynders, Sharar Ahmadi, Jake Aylmer, Laura Baker, David Case, Emanuele Silvio Gentile, Steve George, Kevin Hodges, Eliza Karlowska, Charlotte Lang, Hua Lu, Niamh O'Callaghan, Weronika Osmolska, Scott Osprey, Tony Phillips, David Schröder, Robin Smith, Andrew G. Turner, Steve Woolnough, Martin Andrews, Andrew Coward, Steven Hardiman, James Harle, John W. Rostron, David M. H. Sexton, Bablu Sinha, Jonny Williams, and Chris Wilson
EGUsphere, https://doi.org/10.5194/egusphere-2026-2281, https://doi.org/10.5194/egusphere-2026-2281, 2026
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
Short summary
Short summary
This paper presents a new large ensemble of climate model simulations: The CANARI HadGEM3 Large Ensemble (CANARI LE). The CANARI LE has a comparatively high resolution, provides sub-daily output on atmospheric pressure levels, and boundary conditions for driving regional model simulations. The CANARI LE is thus a community resource that lends itself for the study of physical coupled climate processes, weather systems, and impacts in a changing climate.
Aleena M. Jaison, Lesley J. Gray, Scott M. Osprey, James A. Anstey, Martin B. Andrews, Neal Butchart, Zhaoyang Chai, Dong-Chan Hong, Kai Huang, Yoshio Kawatani, Jeff R. Knight, Pu Lin, Francois Lott, Yixiong Lu, Hiroaki Naoe, Jadwiga H. Richter, Nan Rosenbloom, Federico Serva, Anne K. Smith, Seok-Woo Son, Qi Tang, Shingo Watanabe, Jinbo Xie, and Kohei Yoshida
EGUsphere, https://doi.org/10.5194/egusphere-2026-4135, https://doi.org/10.5194/egusphere-2026-4135, 2026
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
Short summary
Short summary
The tropical upper stratosphere has winds that switch between westerly and easterly every six months known as the semi-annual oscillation (SAO). Climate models commonly show an easterly bias in the SAO. We analysed data from many models to test if correcting the biases in winds lower in the stratosphere could improve SAO. We find correcting the lower-level wind biases reduces the SAO easterly bias, though further improvements, such as better representation of atmospheric waves, are still needed.
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
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.
Hyun-Kyu Lee, James A. Anstey, Hye-Yeong Chun, Shingo Watanabe, Francois Lott, Zhaoyang Chai, Yixiong Lu, Qi Tang, Jinbo Xie, Dong-Chan Hong, Seok-Woo Son, Federico Serva, Pu Lin, Martin B. Andrews, Neal Butchart, Aleena M. Jaison, Jeff R. Knight, Scott Osprey, Hiroaki Naoe, Kohei Yoshida, Yoshio Kawatani, and Jadwiga H. Richter
EGUsphere, https://doi.org/10.5194/egusphere-2026-2856, https://doi.org/10.5194/egusphere-2026-2856, 2026
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Li Xu, Qi Tang, Qing Zhu, William J. Riley, Guido R. van der Werf, Yang Chen, Michael J. Prather, and James T. Randerson
EGUsphere, https://doi.org/10.5194/egusphere-2026-4288, https://doi.org/10.5194/egusphere-2026-4288, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Using the E3SM version 3 model with interactive chemistry, this study shows that wildfires substantially perturb global and regional tropospheric chemistry and modify radiative effects through aerosol and ozone interactions, with particularly strong impacts in tropical fire regions. By connecting wildfire emissions with changes in atmospheric composition, radiation, and climate, this study provides important insights on how the atmosphere responds to changing fire activities.
Daniele Visioni, Alan Robock, Alistair Duffey, Matthew Henry, Haruki Hirasawa, Walker Raymond Lee, Cindy Wang, Kelsey Roberts, Shingo Watanabe, Michelle Simões Reboita, Masahiro Sugiyama, Ben Kravitz, Jim Haywood, Simone Tilmes, Frédéric K. Bonou, Jack Chen, Timofei Sukhodolov, Sandro Vattioni, Andrin Jörimann, Diego Villanueva, Ryan Vella, Paul Farron, Ewa Bednarz, Ulrike Niemeier, Colleen Golja, and Juan A. Añel
Geosci. Model Dev., 19, 8469–8499, https://doi.org/10.5194/gmd-19-8469-2026, https://doi.org/10.5194/gmd-19-8469-2026, 2026
Short summary
Short summary
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.
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
Atmos. Chem. Phys., 26, 12751–12770, https://doi.org/10.5194/acp-26-12751-2026, https://doi.org/10.5194/acp-26-12751-2026, 2026
Short summary
Short summary
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 (Geoengineering Model Intercomparison Project) G6-1.5K-SAI (Stratospheric Aerosol Injection) 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.
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
Geosci. Model Dev., 19, 8053–8079, https://doi.org/10.5194/gmd-19-8053-2026, https://doi.org/10.5194/gmd-19-8053-2026, 2026
Short summary
Short summary
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.
Carly KleinStern, Benjamin Clouser, Thaopaul Bui, Jonathan Dean-Day, Adrien Desmoulin, James Franke, Hisashi Nakamura, Rei Ueyama, Shingo Watanabe, and Elisabeth Moyer
EGUsphere, https://doi.org/10.5194/egusphere-2026-4533, https://doi.org/10.5194/egusphere-2026-4533, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Tropical cyclones (TCs) create gravity waves that spread in near-concentric rings above the storm, creating temperature fluctuations that help dry the stratosphere via cirrus formation. Understanding the amplitudes of those waves has been difficult because few direct measurements exist. We show new measurements taken during a high-altitude overflight of TC Hinnamnor in 2022. The large wave observed suggests that TC gravity waves are underestimated in the commonly-used ERA5 reanalysis.
Walker Raymond Lee, Simone Tilmes, and Ewa M. Bednarz
Earth Syst. Dynam., 17, 1117–1134, https://doi.org/10.5194/esd-17-1117-2026, https://doi.org/10.5194/esd-17-1117-2026, 2026
Short summary
Short summary
We present climate model simulation of stratospheric aerosol injection, a proposed method of climate intervention where reflective particles are placed in the stratosphere to cool the planet. We design our simulated interventions to maintain certain surface temperature patterns, and show that the same temperatures can be maintained in different ways because of how the ocean transports heat. This has implications for how climate intervention model experiments are designed in the future.
William J. M. Seviour, Justin Finkel, Philip Rupp, Regan Mudhar, Amy H. Butler, Chaim I. Garfinkel, Peter Hitchcock, Blanca Ayarzagüena, Dong-Chan Hong, Yu-Kyung Hyun, Hera Kim, Eun-Pa Lim, Daniel De Maeseneire, Gabriele Messori, Gerbrand Koren, Michael Sigmond, Isla R. Simpson, and Seok-Woo Son
Weather Clim. Dynam., 7, 1405–1423, https://doi.org/10.5194/wcd-7-1405-2026, https://doi.org/10.5194/wcd-7-1405-2026, 2026
Short summary
Short summary
Variability of the stratospheric polar vortex is thought to play a role in driving weather extremes, but quantifying this role for a given event has proved challenging. Using a new set of perturbed subseasonal forecast experiments from 7 modelling centres, we determine the stratospheric contribution to the risk and severity of three recent extreme weather events. The forecast-based methodology that we develop is applicable to understanding a range of other drivers of weather extremes.
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
Atmos. Chem. Phys., 26, 11355–11370, https://doi.org/10.5194/acp-26-11355-2026, https://doi.org/10.5194/acp-26-11355-2026, 2026
Short summary
Short summary
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 (Southern Hemisphere) 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.
Andrin Jörimann, Timofei Sukhodolov, Simone Tilmes, David Plummer, Shingo Watanabe, Hideharu Akiyoshi, Gabriel Chiodo, Daniele Visioni, Sandro Vattioni, Eugene Rozanov, Ewa Monika Bednarz, Béatrice Josse, Yousuke Yamashita, and Thomas Peter
Atmos. Chem. Phys., 26, 11207–11234, https://doi.org/10.5194/acp-26-11207-2026, https://doi.org/10.5194/acp-26-11207-2026, 2026
Short summary
Short summary
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 changes varies considerably.
Reinhard K. H. Schiemann, Grenville Lister, Rosalyn Hatcher, Dan Hodson, Bryan Lawrence, Len Shaffrey, Jeff Cole, Andrea Dittus, Jenny Mecking, Jon Robson, Simon Wilson, Yevgeny Aksenov, Adam T. Blaker, Ben Harvey, Oscar Martínez-Alvarado, Annette Osprey, Stephanie Rynders, Sharar Ahmadi, Jake Aylmer, Laura Baker, David Case, Emanuele Silvio Gentile, Steve George, Kevin Hodges, Eliza Karlowska, Charlotte Lang, Hua Lu, Niamh O'Callaghan, Weronika Osmolska, Scott Osprey, Tony Phillips, David Schröder, Robin Smith, Andrew G. Turner, Steve Woolnough, Martin Andrews, Andrew Coward, Steven Hardiman, James Harle, John W. Rostron, David M. H. Sexton, Bablu Sinha, Jonny Williams, and Chris Wilson
EGUsphere, https://doi.org/10.5194/egusphere-2026-2281, https://doi.org/10.5194/egusphere-2026-2281, 2026
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
Short summary
Short summary
This paper presents a new large ensemble of climate model simulations: The CANARI HadGEM3 Large Ensemble (CANARI LE). The CANARI LE has a comparatively high resolution, provides sub-daily output on atmospheric pressure levels, and boundary conditions for driving regional model simulations. The CANARI LE is thus a community resource that lends itself for the study of physical coupled climate processes, weather systems, and impacts in a changing climate.
Mengzhe Zheng, Tongwen Wu, Yixiong Lu, Weihua Jie, Yiming Liu, Xiaoge Xin, Jie Zhang, He Zhao, Xindan Zhang, and Jiajie Yang
Geosci. Model Dev., 19, 7279–7301, https://doi.org/10.5194/gmd-19-7279-2026, https://doi.org/10.5194/gmd-19-7279-2026, 2026
Short summary
Short summary
The dynamic evolution and interactions of aerosols are first incorporated into the China Meteorological Administration Climate Prediction System version 4 (CMA-CPSv4). This paper evaluates the prediction system's simulation performance for aerosols. The results show that the CMA-CPSv4 reasonably simulates the spatial distribution of aerosols. The reasonable simulation of aerosols is fundamental for studying the impact of aerosols on climate prediction in our next work.
Raina Roy, Julie M. Arblaster, Matthew C. Wheeler, Eun-Pa Lim, and Jadwiga H. Richter
Weather Clim. Dynam., 7, 1385–1403, https://doi.org/10.5194/wcd-7-1385-2026, https://doi.org/10.5194/wcd-7-1385-2026, 2026
Short summary
Short summary
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.
Colleen Marie Golja, Marianna Linz, Ewa Monika Bednarz, Daniele Visioni, Ben Kravitz, John A. Dykema, Michelle E. Frazer, Anthony C. Jones, Isla R. Simpson, and Shingo Watanabe
EGUsphere, https://doi.org/10.5194/egusphere-2026-4200, https://doi.org/10.5194/egusphere-2026-4200, 2026
Short summary
Short summary
Adding reflective particles to the stratosphere has been proposed to cool the planet, but how the resulting lower-stratospheric heating affects the broader climate remains unclear. This study simulates idealized lower-stratospheric heating across five climate models finding large inter-model differences in the stratospheric and surface response. The results highlight ways in which these differences may be explained by biases in the stratospheric climatological mean state.
Chaim I. Garfinkel, David Avisar, Wenjuan Huo, Ales Kuchar, Shoshiro Minobe, Scott Osprey, Katharina Perny, and Jonathon S. Wright
EGUsphere, https://doi.org/10.5194/egusphere-2026-3738, https://doi.org/10.5194/egusphere-2026-3738, 2026
Short summary
Short summary
Whether tropical volcanic eruptions lead to a circulation response in winter is still unclear. We re-evaluate this effect using large ensembles from eight separate models with only one time-varying external forcing: volcanic aerosols. We find that 75 % of models simulate the previously proposed effect, but that the signal requires at least 30 eruptions before it emerges robustly from the noise. Furthermore, we demonstrate that the El Niño signal differs from natural El Niño events.
Hongbin Chen, Jian Rao, Seok-Woo Son, Bin Guan, and Mengxin Pan
Earth Syst. Sci. Data, 18, 5357–5373, https://doi.org/10.5194/essd-18-5357-2026, https://doi.org/10.5194/essd-18-5357-2026, 2026
Short summary
Short summary
We present a global atmospheric river (AR) database derived from ERA5 reanalysis (1940–2024). By employing a novel multi-method fusion algorithm, this database provides AR identification results at a horizontal resolution of 1° × 1° and a temporal resolution of 6 hours. Characterized by enhanced algorithmic robustness and extensive temporal coverage, it offers a valuable resource for further weather and climate research.
Aleena M. Jaison, Lesley J. Gray, Scott M. Osprey, James A. Anstey, Martin B. Andrews, Neal Butchart, Zhaoyang Chai, Dong-Chan Hong, Kai Huang, Yoshio Kawatani, Jeff R. Knight, Pu Lin, Francois Lott, Yixiong Lu, Hiroaki Naoe, Jadwiga H. Richter, Nan Rosenbloom, Federico Serva, Anne K. Smith, Seok-Woo Son, Qi Tang, Shingo Watanabe, Jinbo Xie, and Kohei Yoshida
EGUsphere, https://doi.org/10.5194/egusphere-2026-4135, https://doi.org/10.5194/egusphere-2026-4135, 2026
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
Short summary
Short summary
The tropical upper stratosphere has winds that switch between westerly and easterly every six months known as the semi-annual oscillation (SAO). Climate models commonly show an easterly bias in the SAO. We analysed data from many models to test if correcting the biases in winds lower in the stratosphere could improve SAO. We find correcting the lower-level wind biases reduces the SAO easterly bias, though further improvements, such as better representation of atmospheric waves, are still needed.
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
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
Weather Clim. Dynam., 7, 1133–1152, https://doi.org/10.5194/wcd-7-1133-2026, https://doi.org/10.5194/wcd-7-1133-2026, 2026
Short summary
Short summary
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.
Hyun-Kyu Lee, James A. Anstey, Hye-Yeong Chun, Shingo Watanabe, Francois Lott, Zhaoyang Chai, Yixiong Lu, Qi Tang, Jinbo Xie, Dong-Chan Hong, Seok-Woo Son, Federico Serva, Pu Lin, Martin B. Andrews, Neal Butchart, Aleena M. Jaison, Jeff R. Knight, Scott Osprey, Hiroaki Naoe, Kohei Yoshida, Yoshio Kawatani, and Jadwiga H. Richter
EGUsphere, https://doi.org/10.5194/egusphere-2026-2856, https://doi.org/10.5194/egusphere-2026-2856, 2026
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
Short summary
Short summary
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.
Aleena M. Jaison, Paulo Ceppi, and Sarah Wilson Kemsley
EGUsphere, https://doi.org/10.5194/egusphere-2026-2841, https://doi.org/10.5194/egusphere-2026-2841, 2026
Short summary
Short summary
We investigate how stratospheric winds influence high clouds using satellite observations and climate models. These winds, known as the quasi-biennial oscillation, alter meteorological conditions in the troposphere such as upper-tropospheric temperature, stability, and humidity, and clouds respond to these changes. Reducing model biases requires improving cloud sensitivity to these factors. This framework could also help assess cloud responses to stratospheric cooling driven by climate change.
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
Atmos. Chem. Phys., 26, 7677–7704, https://doi.org/10.5194/acp-26-7677-2026, https://doi.org/10.5194/acp-26-7677-2026, 2026
Short summary
Short summary
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.
Dong-Chan Hong, Seok-Woo Son, Blanca Ayarzagüena, Amy H. Butler, Chaim I. Garfinkel, Peter Hitchcock, Yu-Kyung Hyun, and Jiankai Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2026-2798, https://doi.org/10.5194/egusphere-2026-2798, 2026
Short summary
Short summary
This study investigates how Sudden Stratospheric Warming (SSW) influences surface climate. By comparing multi-model simulations, we isolated and quantified the role of SSWs. Results reveal that poleward mass transport during SSWs induces high pressure over the Arctic, driving changes in extratropical circulations. While SSWs alter the troposphere, chaotic internal weather variability can amplify or suppress their influence, explaining the differing surface impacts following SSWs.
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
Atmos. Chem. Phys., 26, 7463–7483, https://doi.org/10.5194/acp-26-7463-2026, https://doi.org/10.5194/acp-26-7463-2026, 2026
Short summary
Short summary
Stratospheric aerosol injection (SAI) is a proposed method of cooling the planet by introducing reflective particles called aerosols into the middle atmosphere to reflect sunlight back into space. We consider recent simulations of SAI from four different climate models. SAI cools the planet effectively in all four models; we examine the impacts on temperature and precipitation in each model and compare to previous experiments. Our simulations will help inform future research and policy.
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
Short summary
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
Atmos. Chem. Phys., 26, 5249–5291, https://doi.org/10.5194/acp-26-5249-2026, https://doi.org/10.5194/acp-26-5249-2026, 2026
Short summary
Short summary
Accurate representation of stratospheric transport in Chemistry-Climate Models is essential for reliable climate projections. This study evaluates three generations of models using observational data and reanalyses, identifying persistent biases and their potential causes. Some biases persist or even worsen in newer models. These findings highlight key limitations and inform efforts to improve models and advance understanding through process-based studies and enhanced observations.
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
Short summary
Short summary
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.
Vinay Kumar, Shigeo Yoden, Matthew H. Hitchman, Tetsuya Takemi, and Kosuke Ito
Atmos. Chem. Phys., 26, 4547–4569, https://doi.org/10.5194/acp-26-4547-2026, https://doi.org/10.5194/acp-26-4547-2026, 2026
Short summary
Short summary
This study provides an insightful view on possible teleconnections between the stratospheric Quasi-biennial oscillation (QBO) and global monsoon system. It is observed that the QBO has dynamical teleconnections with different regional monsoons where prominent dynamical circulations prevail, and primarily modulates these circulations, thereby influencing the associated precipitation patterns. The findings would enable us to improve long-range forecasting for global monsoon system.
Jared Farley, Douglas G. MacMartin, Daniele Visioni, Ben Kravitz, Ewa M. Bednarz, Alistair Duffey, Matthew Henry, and Ali Akherati
Geosci. Model Dev., 19, 1809–1831, https://doi.org/10.5194/gmd-19-1809-2026, https://doi.org/10.5194/gmd-19-1809-2026, 2026
Short summary
Short summary
As the climate changes, many are studying sunlight reflection as a potential method of cooling. Such climate intervention could be deployed in many possible ways, including in scenarios where not every actor agrees on the strategy of cooling. These scenarios are so diverse that to explore all of them using earth system models proves to be too costly. In this paper, we develop a simplified climate model that allows users to easily explore climate intervention scenarios of their choice.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Wilson Chan, Katie A. Facer-Childs, Maliko Tanguy, Eugene Magee, Burak Bulut, Nicky Stringer, Jeff Knight, and Jamie Hannaford
Hydrol. Earth Syst. Sci., 30, 905–927, https://doi.org/10.5194/hess-30-905-2026, https://doi.org/10.5194/hess-30-905-2026, 2026
Short summary
Short summary
The UK Hydrological Outlook river flow forecasting system recently implemented the Historic Weather Analogues method. The method improves winter river flow forecast skill across the UK, especially in upland, fast-responding catchments with low catchment storage. Forecast skill is highest in winter due to accurate prediction of atmospheric circulation patterns like the North Atlantic Oscillation. The Ensemble Streamflow prediction method remains a robust benchmark, especially for other seasons.
Jie Zhang, Kalli Furtado, Steven T. Turnock, Yixiong Lu, Tongwen Wu, Fang Zhang, Xiaoge Xin, and Yuyun Liu
Atmos. Chem. Phys., 26, 2175–2189, https://doi.org/10.5194/acp-26-2175-2026, https://doi.org/10.5194/acp-26-2175-2026, 2026
Short summary
Short summary
Aerosol cooling has been identified as a key driver of the cold biases in CMIP6 (sixth Coupled Model Inter-comparison Project) models. We demonstrate the critical role of sulfate burden anomaly and the contribution of sulfur removal processes. Faster sulfate deposition directly lowers atmospheric sulfate levels, while enhanced SO₂ deposition reduces the precursor for sulfate formation. The systematically short sulfate lifetime implies that model improvements should focus on SO₂ deposition processes, rather than sulfate deposition.
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
Short summary
Short summary
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.
Cindy Wang, Daniele Visioni, Glen Chua, and Ewa M. Bednarz
Atmos. Chem. Phys., 26, 1339–1357, https://doi.org/10.5194/acp-26-1339-2026, https://doi.org/10.5194/acp-26-1339-2026, 2026
Short summary
Short summary
Stratospheric aerosol injection is a proposed method to slow global warming by adding tiny reflective particles high up in the atmosphere to cool the planet. We study how this proposed method might affect air quality and human health using climate models. We find that the health impacts would likely be small and are mainly driven by changes in climate, not by the particles themselves.
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
Short summary
Short summary
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.
Ewa M. Bednarz, Amy H. Butler, Xinyue Wang, Zhihong Zhuo, Wandi Yu, Georgiy Stenchikov, Matthew Toohey, and Yunqian Zhu
Atmos. Chem. Phys., 26, 197–215, https://doi.org/10.5194/acp-26-197-2026, https://doi.org/10.5194/acp-26-197-2026, 2026
Short summary
Short summary
We investigate whether the 2022 Hunga eruption could affect surface climate via indirect pathways using large ensembles of Earth System Model simulations. These suggest that the eruption could have a non-negligible influence on regional surface climate, and we discuss the mechanisms via which such an influence could occur but also highlight that the forcing is relatively weak compared to natural climate variability which significantly hinders the detection of such impacts in the real world.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Allen Hu, Ziming Ke, Xiaohong Liu, Benjamin Wagman, Hunter Brown, Zheng Lu, Mingxuan Wu, Hailong Wang, Qi Tang, Diana Bull, Kara Peterson, and Shaocheng Xie
Atmos. Chem. Phys., 25, 12137–12157, https://doi.org/10.5194/acp-25-12137-2025, https://doi.org/10.5194/acp-25-12137-2025, 2025
Short summary
Short summary
Volcanic eruptions have major effects on atmospheric temperature and can be studied as a proxy for geo-engineering. The original aerosol module in the Energy Exascale Earth System Model v2 (E3SMv2) has problems simulating volcanic aerosols. We alter the aerosol module to simulate the 1991 Pinatubo eruption and implement a more complex chemistry scheme, producing results that better agree with observations. Process analyses of the volcanic aerosols help explain how they grow in the stratosphere.
Yoshio Kawatani, Kevin Hamilton, Shingo Watanabe, Masakazu Taguchi, Federico Serva, James A. Anstey, Jadwiga H. Richter, Neal Butchart, Clara Orbe, Scott M. Osprey, Hiroaki Naoe, Dillon Elsbury, Chih-Chieh Chen, Javier García-Serrano, Anne Glanville, Tobias Kerzenmacher, François Lott, Froila M. Palmeiro, Mijeong Park, Stefan Versick, and Kohei Yoshida
Weather Clim. Dynam., 6, 1045–1073, https://doi.org/10.5194/wcd-6-1045-2025, https://doi.org/10.5194/wcd-6-1045-2025, 2025
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Ezra Brody, Yan Zhang, Douglas G. MacMartin, Daniele Visioni, Ben Kravitz, and Ewa M. Bednarz
Earth Syst. Dynam., 16, 1325–1341, https://doi.org/10.5194/esd-16-1325-2025, https://doi.org/10.5194/esd-16-1325-2025, 2025
Short summary
Short summary
Stratospheric aerosol injection (SAI) is being studied as a possible supplement to emission reduction to temporarily mitigate some of the risks associated with climate change. The latitudes at which SAI is done determine the effect on the climate. We try to find if there are combinations of latitudes that do a better job of counteracting climate change than existing strategies. We found that there are, but just how significant these improvements are depends on the amount of cooling.
Mark D. Rhodes-Smith, Victoria A. Bell, Nicky Stringer, Helen Baron, Helen Davies, and Jeff Knight
EGUsphere, https://doi.org/10.5194/egusphere-2025-2506, https://doi.org/10.5194/egusphere-2025-2506, 2025
Short summary
Short summary
River flow forecasts up to three months ahead can allow early preparations for future floods and droughts. We test a new forecasting system using weather forecasts made by selecting historical weather patterns that match current conditions and running them through a simulation of Great Britain's rivers. Our tests show that this system performs particularly well in the winter and spring, in northern Scotland and in southern England. We now use this system to produce forecasts regularly.
Ziming Ke, Qi Tang, Jean-Christophe Golaz, Xiaohong Liu, and Hailong Wang
Geosci. Model Dev., 18, 4137–4153, https://doi.org/10.5194/gmd-18-4137-2025, https://doi.org/10.5194/gmd-18-4137-2025, 2025
Short summary
Short summary
This study assesses volcanic aerosol representation in E3SM (Energy Exascale Earth System Model), showing that an emission-based approach moderately improves temperature variability and cloud responses compared to a prescribed forcing approach, yet significant bias persists.
Simone Tilmes, Ewa M. Bednarz, Andrin Jörimann, Daniele Visioni, Douglas E. Kinnison, Gabriel Chiodo, and David Plummer
Atmos. Chem. Phys., 25, 6001–6023, https://doi.org/10.5194/acp-25-6001-2025, https://doi.org/10.5194/acp-25-6001-2025, 2025
Short summary
Short summary
In this paper, we describe the details of a new multi-model intercomparison experiment to assess the effects of Stratospheric Aerosol Intervention (SAI) on stratospheric chemistry and dynamics and, therefore, ozone. Second, we discuss the advantages and differences of the more constrained experiment compared to fully interactive model experiments. This way, we advance the process-level understanding of the drivers of SAI-induced atmospheric responses.
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
Short summary
Short summary
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.
Katherine M. Smith, Alice M. Barthel, LeAnn M. Conlon, Luke P. Van Roekel, Anthony Bartoletti, Jean-Christophe Golaz, Chengzhu Zhang, Carolyn Branecky Begeman, James J. Benedict, Gautam Bisht, Yan Feng, Walter Hannah, Bryce E. Harrop, Nicole Jeffery, Wuyin Lin, Po-Lun Ma, Mathew E. Maltrud, Mark R. Petersen, Balwinder Singh, Qi Tang, Teklu Tesfa, Jonathan D. Wolfe, Shaocheng Xie, Xue Zheng, Karthik Balaguru, Oluwayemi Garuba, Peter Gleckler, Aixue Hu, Jiwoo Lee, Ben Moore-Maley, and Ana C. Ordoñez
Geosci. Model Dev., 18, 1613–1633, https://doi.org/10.5194/gmd-18-1613-2025, https://doi.org/10.5194/gmd-18-1613-2025, 2025
Short summary
Short summary
Version 2.1 of the U.S. Department of Energy's Energy Exascale Earth System Model (E3SM) adds the Fox-Kemper et al. (2011) mixed-layer eddy parameterization, which restratifies the ocean surface layer through an overturning streamfunction. Results include surface layer bias reduction in temperature, salinity, and sea ice extent in the North Atlantic; a small strengthening of the Atlantic meridional overturning circulation; and improvements to many atmospheric climatological variables.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Matthew Henry, Ewa M. Bednarz, and Jim Haywood
Atmos. Chem. Phys., 24, 13253–13268, https://doi.org/10.5194/acp-24-13253-2024, https://doi.org/10.5194/acp-24-13253-2024, 2024
Short summary
Short summary
Stratospheric aerosol injection (SAI) refers to a climate intervention by which aerosols are intentionally added to the high atmosphere to increase the amount of reflected sunlight and reduce Earth's temperature. The climate outcomes of SAI depend on the latitude of injection. While injecting aerosols at the Equator has undesirable side effects, injecting away from the Equator has different effects on temperature, rainfall, ozone, and atmospheric circulation, which are analysed in this work.
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
Short summary
Short summary
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.
Peter A. Bogenschutz, Jishi Zhang, Qi Tang, and Philip Cameron-Smith
Geosci. Model Dev., 17, 7029–7050, https://doi.org/10.5194/gmd-17-7029-2024, https://doi.org/10.5194/gmd-17-7029-2024, 2024
Short summary
Short summary
Using high-resolution and state-of-the-art modeling techniques we simulate five atmospheric river events for California to test the capability to represent precipitation for these events. We find that our model is able to capture the distribution of precipitation very well but suffers from overestimating the precipitation amounts over high elevation. Increasing the resolution further has no impact on reducing this bias, while increasing the domain size does have modest impacts.
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
Preprint archived
Short summary
Short summary
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
Short summary
Short summary
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.
Jishi Zhang, Peter Bogenschutz, Qi Tang, Philip Cameron-smith, and Chengzhu Zhang
Geosci. Model Dev., 17, 3687–3731, https://doi.org/10.5194/gmd-17-3687-2024, https://doi.org/10.5194/gmd-17-3687-2024, 2024
Short summary
Short summary
We developed a regionally refined climate model that allows resolved convection and performed a 20-year projection to the end of the century. The model has a resolution of 3.25 km in California, which allows us to predict climate with unprecedented accuracy, and a resolution of 100 km for the rest of the globe to achieve efficient, self-consistent simulations. The model produces superior results in reproducing climate patterns over California that typical modern climate models cannot resolve.
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
Short summary
Short summary
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.
Yan Zhang, Douglas G. MacMartin, Daniele Visioni, Ewa M. Bednarz, and Ben Kravitz
Earth Syst. Dynam., 15, 191–213, https://doi.org/10.5194/esd-15-191-2024, https://doi.org/10.5194/esd-15-191-2024, 2024
Short summary
Short summary
Injecting SO2 into the lower stratosphere can temporarily reduce global mean temperature and mitigate some risks associated with climate change, but injecting it at different latitudes and seasons would have different impacts. This study introduces new stratospheric aerosol injection (SAI) strategies and explores the importance of the choice of SAI strategy, demonstrating that it notably affects the distribution of aerosol cloud, injection efficiency, and various surface climate impacts.
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
Short summary
Short summary
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.
Hsiang-He Lee, Qi Tang, and Michael Prather
Geosci. Model Dev. Discuss., https://doi.org/10.5194/gmd-2023-203, https://doi.org/10.5194/gmd-2023-203, 2024
Revised manuscript not accepted
Short summary
Short summary
The E3SM Chemistry diagnostics package (ChemDyg) is a software tool, which is designed for the global climate model (E3SM) chemistry development. ChemDyg generates several diagnostic plots and tables for model-to-model and model-to-observation comparison, including 2-dimentional contour mapping plots, diurnal and annual cycle, time-series plots, and comprehensive processing tables. This paper is to introduce the details of each diagnostics set and its required input data formats in ChemDyg.
Yuying Zhang, Shaocheng Xie, Yi Qin, Wuyin Lin, Jean-Christophe Golaz, Xue Zheng, Po-Lun Ma, Yun Qian, Qi Tang, Christopher R. Terai, and Meng Zhang
Geosci. Model Dev., 17, 169–189, https://doi.org/10.5194/gmd-17-169-2024, https://doi.org/10.5194/gmd-17-169-2024, 2024
Short summary
Short summary
We performed systematic evaluation of clouds simulated in the Energy
Exascale Earth System Model (E3SMv2) to document model performance and understand what updates in E3SMv2 have caused changes in clouds from E3SMv1 to E3SMv2. We find that stratocumulus clouds along the subtropical west coast of continents are dramatically improved, primarily due to the retuning done in CLUBB. This study offers additional insights into clouds simulated in E3SMv2 and will benefit future E3SM developments.
Exascale Earth System Model (E3SMv2) to document model performance and understand what updates in E3SMv2 have caused changes in clouds from E3SMv1 to E3SMv2. We find that stratocumulus clouds along the subtropical west coast of continents are dramatically improved, primarily due to the retuning done in CLUBB. This study offers additional insights into clouds simulated in E3SMv2 and will benefit future E3SM developments.
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
Short summary
Short summary
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.
Ewa M. Bednarz, Amy H. Butler, Daniele Visioni, Yan Zhang, Ben Kravitz, and Douglas G. MacMartin
Atmos. Chem. Phys., 23, 13665–13684, https://doi.org/10.5194/acp-23-13665-2023, https://doi.org/10.5194/acp-23-13665-2023, 2023
Short summary
Short summary
We use a state-of-the-art Earth system model and a set of stratospheric aerosol injection (SAI) strategies to achieve the same level of global mean surface cooling through different combinations of location and/or timing of the injection. We demonstrate that the choice of SAI strategy can lead to contrasting impacts on stratospheric and tropospheric temperatures, circulation, and chemistry (including stratospheric ozone), thereby leading to different impacts on regional surface climate.
Ewa M. Bednarz, Ryan Hossaini, and Martyn P. Chipperfield
Atmos. Chem. Phys., 23, 13701–13711, https://doi.org/10.5194/acp-23-13701-2023, https://doi.org/10.5194/acp-23-13701-2023, 2023
Short summary
Short summary
We quantify, for the first time, the time-varying impact of uncontrolled emissions of chlorinated very short-lived substances (Cl-VSLSs) on stratospheric ozone using a state-of-the-art chemistry-climate model. We demonstrate that Cl-VSLSs already have a non-negligible impact on stratospheric ozone, including a local reduction of up to ~7 DU in Arctic ozone in the cold winter of 2019/20, and any so future growth in emissions will continue to offset some of the benefits of the Montreal Protocol.
Ewa M. Bednarz, Ryan Hossaini, N. Luke Abraham, and Martyn P. Chipperfield
Geosci. Model Dev., 16, 6187–6209, https://doi.org/10.5194/gmd-16-6187-2023, https://doi.org/10.5194/gmd-16-6187-2023, 2023
Short summary
Short summary
Development and performance of the new DEST chemistry scheme of UM–UKCA is described. The scheme extends the standard StratTrop scheme by including important updates to the halogen chemistry, thus allowing process-oriented studies of stratospheric ozone depletion and recovery, including impacts from both controlled long-lived ozone-depleting substances and emerging issues around uncontrolled, very short-lived substances. It will thus aid studies in support of future ozone assessment reports.
Matthew Henry, Jim Haywood, Andy Jones, Mohit Dalvi, Alice Wells, Daniele Visioni, Ewa M. Bednarz, Douglas G. MacMartin, Walker Lee, and Mari R. Tye
Atmos. Chem. Phys., 23, 13369–13385, https://doi.org/10.5194/acp-23-13369-2023, https://doi.org/10.5194/acp-23-13369-2023, 2023
Short summary
Short summary
Solar climate interventions, such as injecting sulfur in the stratosphere, may be used to offset some of the adverse impacts of global warming. We use two independently developed Earth system models to assess the uncertainties around stratospheric sulfur injections. The injection locations and amounts are optimized to maintain the same pattern of surface temperature. While both models show reduced warming, the change in rainfall patterns (even without sulfur injections) is uncertain.
Qi Tang, Jean-Christophe Golaz, Luke P. Van Roekel, Mark A. Taylor, Wuyin Lin, Benjamin R. Hillman, Paul A. Ullrich, Andrew M. Bradley, Oksana Guba, Jonathan D. Wolfe, Tian Zhou, Kai Zhang, Xue Zheng, Yunyan Zhang, Meng Zhang, Mingxuan Wu, Hailong Wang, Cheng Tao, Balwinder Singh, Alan M. Rhoades, Yi Qin, Hong-Yi Li, Yan Feng, Yuying Zhang, Chengzhu Zhang, Charles S. Zender, Shaocheng Xie, Erika L. Roesler, Andrew F. Roberts, Azamat Mametjanov, Mathew E. Maltrud, Noel D. Keen, Robert L. Jacob, Christiane Jablonowski, Owen K. Hughes, Ryan M. Forsyth, Alan V. Di Vittorio, Peter M. Caldwell, Gautam Bisht, Renata B. McCoy, L. Ruby Leung, and David C. Bader
Geosci. Model Dev., 16, 3953–3995, https://doi.org/10.5194/gmd-16-3953-2023, https://doi.org/10.5194/gmd-16-3953-2023, 2023
Short summary
Short summary
High-resolution simulations are superior to low-resolution ones in capturing regional climate changes and climate extremes. However, uniformly reducing the grid size of a global Earth system model is too computationally expensive. We provide an overview of the fully coupled regionally refined model (RRM) of E3SMv2 and document a first-of-its-kind set of climate production simulations using RRM at an economic cost. The key to this success is our innovative hybrid time step method.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Daniele Visioni, Ewa M. Bednarz, Walker R. Lee, Ben Kravitz, Andy Jones, Jim M. Haywood, and Douglas G. MacMartin
Atmos. Chem. Phys., 23, 663–685, https://doi.org/10.5194/acp-23-663-2023, https://doi.org/10.5194/acp-23-663-2023, 2023
Short summary
Short summary
The paper constitutes Part 1 of a study performing a first systematic inter-model comparison of the atmospheric responses to stratospheric sulfate aerosol injections (SAIs) at various latitudes as simulated by three state-of-the-art Earth system models. We identify similarities and differences in the modeled aerosol burden, investigate the differences in the aerosol approaches between the models, and ultimately show the differences produced in surface climate, temperature and precipitation.
Peter A. Bogenschutz, Hsiang-He Lee, Qi Tang, and Takanobu Yamaguchi
Geosci. Model Dev., 16, 335–352, https://doi.org/10.5194/gmd-16-335-2023, https://doi.org/10.5194/gmd-16-335-2023, 2023
Short summary
Short summary
Models that are used to simulate and predict climate often have trouble representing specific cloud types, such as stratocumulus, that are particularly thin in the vertical direction. It has been found that increasing the model resolution can help improve this problem. In this paper, we develop a novel framework that increases the horizontal and vertical resolutions only for areas of the globe that contain stratocumulus, hence reducing the model runtime while providing better results.
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
Short summary
Short summary
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
Short summary
Short summary
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.
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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
Short summary
Short summary
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.
Ewa M. Bednarz, Ryan Hossaini, Martyn P. Chipperfield, N. Luke Abraham, and Peter Braesicke
Atmos. Chem. Phys., 22, 10657–10676, https://doi.org/10.5194/acp-22-10657-2022, https://doi.org/10.5194/acp-22-10657-2022, 2022
Short summary
Short summary
Atmospheric impacts of chlorinated very short-lived substances (Cl-VSLS) over the first two decades of the 21st century are assessed using the UM-UKCA chemistry–climate model. Stratospheric input of Cl from Cl-VSLS is estimated at ~130 ppt in 2019. The use of model set-up with constrained meteorology significantly increases the abundance of Cl-VSLS in the lower stratosphere relative to the free-running set-up. The growth in Cl-VSLS emissions significantly impacted recent HCl and COCl2 trends.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Kai Zhang, Wentao Zhang, Hui Wan, Philip J. Rasch, Steven J. Ghan, Richard C. Easter, Xiangjun Shi, Yong Wang, Hailong Wang, Po-Lun Ma, Shixuan Zhang, Jian Sun, Susannah M. Burrows, Manish Shrivastava, Balwinder Singh, Yun Qian, Xiaohong Liu, Jean-Christophe Golaz, Qi Tang, Xue Zheng, Shaocheng Xie, Wuyin Lin, Yan Feng, Minghuai Wang, Jin-Ho Yoon, and L. Ruby Leung
Atmos. Chem. Phys., 22, 9129–9160, https://doi.org/10.5194/acp-22-9129-2022, https://doi.org/10.5194/acp-22-9129-2022, 2022
Short summary
Short summary
Here we analyze the effective aerosol forcing simulated by E3SM version 1 using both century-long free-running and short nudged simulations. The aerosol forcing in E3SMv1 is relatively large compared to other models, mainly due to the large indirect aerosol effect. Aerosol-induced changes in liquid and ice cloud properties in E3SMv1 have a strong correlation. The aerosol forcing estimates in E3SMv1 are sensitive to the parameterization changes in both liquid and ice cloud processes.
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
Short summary
Short summary
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.
Xue Zheng, Qing Li, Tian Zhou, Qi Tang, Luke P. Van Roekel, Jean-Christophe Golaz, Hailong Wang, and Philip Cameron-Smith
Geosci. Model Dev., 15, 3941–3967, https://doi.org/10.5194/gmd-15-3941-2022, https://doi.org/10.5194/gmd-15-3941-2022, 2022
Short summary
Short summary
We document the model experiments for the future climate projection by E3SMv1.0. At the highest future emission scenario, E3SMv1.0 projects a strong surface warming with rapid changes in the atmosphere, ocean, sea ice, and land runoff. Specifically, we detect a significant polar amplification and accelerated warming linked to the unmasking of the aerosol effects. The impact of greenhouse gas forcing is examined in different climate components.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Simone Tilmes, Daniele Visioni, Andy Jones, James Haywood, Roland Séférian, Pierre Nabat, Olivier Boucher, Ewa Monica Bednarz, and Ulrike Niemeier
Atmos. Chem. Phys., 22, 4557–4579, https://doi.org/10.5194/acp-22-4557-2022, https://doi.org/10.5194/acp-22-4557-2022, 2022
Short summary
Short summary
This study assesses the impacts of climate interventions, using stratospheric sulfate aerosol and solar dimming on stratospheric ozone, based on three Earth system models with interactive stratospheric chemistry. The climate interventions have been applied to a high emission (baseline) scenario in order to reach global surface temperatures of a medium emission scenario. We find significant increases and decreases in total column ozone, depending on regions and seasons.
Po-Lun Ma, Bryce E. Harrop, Vincent E. Larson, Richard B. Neale, Andrew Gettelman, Hugh Morrison, Hailong Wang, Kai Zhang, Stephen A. Klein, Mark D. Zelinka, Yuying Zhang, Yun Qian, Jin-Ho Yoon, Christopher R. Jones, Meng Huang, Sheng-Lun Tai, Balwinder Singh, Peter A. Bogenschutz, Xue Zheng, Wuyin Lin, Johannes Quaas, Hélène Chepfer, Michael A. Brunke, Xubin Zeng, Johannes Mülmenstädt, Samson Hagos, Zhibo Zhang, Hua Song, Xiaohong Liu, Michael S. Pritchard, Hui Wan, Jingyu Wang, Qi Tang, Peter M. Caldwell, Jiwen Fan, Larry K. Berg, Jerome D. Fast, Mark A. Taylor, Jean-Christophe Golaz, Shaocheng Xie, Philip J. Rasch, and L. Ruby Leung
Geosci. Model Dev., 15, 2881–2916, https://doi.org/10.5194/gmd-15-2881-2022, https://doi.org/10.5194/gmd-15-2881-2022, 2022
Short summary
Short summary
An alternative set of parameters for E3SM Atmospheric Model version 1 has been developed based on a tuning strategy that focuses on clouds. When clouds in every regime are improved, other aspects of the model are also improved, even though they are not the direct targets for calibration. The recalibrated model shows a lower sensitivity to anthropogenic aerosols and surface warming, suggesting potential improvements to the simulated climate in the past and future.
Seungmok Paik, Seung-Ki Min, Seok-Woo Son, Soon-Il An, Jong-Seong Kug, and Sang-Wook Yeh
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-187, https://doi.org/10.5194/acp-2022-187, 2022
Revised manuscript not accepted
Short summary
Short summary
This paper investigates Earth’s surface climate response to volcanic eruptions at different latitudes. By analyzing last millennium ensemble simulations of a coupled climate model, we have identified physical processes associated with the diverse impacts of volcanic eruption latitudes, focusing on the tropical ocean surface warming and the stratospheric polar vortex intensification. Our results provide important global implications for atmospheric responses to future volcanic aerosols.
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
Short summary
Short summary
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
Short summary
Short summary
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.
Si Chen, Zhenghui Xie, Jinbo Xie, Bin Liu, Binghao Jia, Peihua Qin, Longhuan Wang, Yan Wang, and Ruichao Li
Earth Syst. Dynam., 13, 341–356, https://doi.org/10.5194/esd-13-341-2022, https://doi.org/10.5194/esd-13-341-2022, 2022
Short summary
Short summary
This study discusses the changes in the summer thermal environment in the Chengdu–Chongqing urban agglomeration due to urban expansion in complex terrain conditions in the recent 40 years, using high-resolution simulations with the WRF model. We quantify the influence of a single urban expansion factor and a single complex terrain factor on the urban thermal environment. Under the joint influence of complex terrain and urban expansion, the heat island effect caused by urbanization was enhanced.
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
Short summary
Short summary
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.
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
Short summary
Short summary
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.
Cited articles
Adler, R. F., Sapiano, M., Huffman, G. J., Wang, J.-J., Gu, G., Bolvin, D., Chiu, L., Schneider, U., Becker, A., Nelkin, E., Xie, P., Ferraro, R., and Shin, D.-B.: The Global Precipitation Climatology Project (GPCP) Monthly Analysis (Version 2.3) and a Review of 2017 Global Precipitation, Atmosphere, 9, 138, https://doi.org/10.3390/atmos9040138, 2018.
Andrews, D. G., Holton, J. R., and Leovy, C. B.: Middle Atmosphere Dynamics, Academic Press, San Diego, CA, 489 pp., ISBN: 978-0-12-058575-5, 1987.
Andrews, M. B., Knight, J. R., Scaife, A. A., and Wicker, W.: Influence of the Quasi-Biennial Oscillation on tropical convection and its teleconnection to the midlatitudes in boreal winter, Q. J. Roy. Meteor. Soc., 150, 2510–2521, https://doi.org/10.1002/qj.4721, 2024.
Anstey, J. A., Butchart, N., Hamilton, K., and Osprey, S. 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., 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., Yoshida, K., and Yukimoto, S.: Teleconnections of the Quasi-Biennial Oscillation in a multi-model ensemble of QBO-resolving models, Q. J. Roy. Meteor. Soc., 148, 1568–1592, https://doi.org/10.1002/qj.4048, 2022b.
Anstey, J., Butchart, N., and Osprey, S.: QBOi Phase-2 Nudging Experiments, Zenodo [data set], https://doi.org/10.5281/zenodo.19059511, 2026a.
Anstey, J. A., Butchart, N., Osprey, S., Kawatani, Y., Hamilton, K., Richter, J. H., Stockdale, T., Andrews, M. B., Chai, Z., Davini, P., Hong, D.-C., Huang, K., Jaison, A. M., Kerzenmacher, T., Knight, J. R., Lin, P., Lott, F., Lu, Y., Naoe, H., Serva, F., Simpson, I., Son, S.-W., Tang, Q., Watanabe, S., Xie, J., and Yoshida, K.: Experiment design, nudging protocol, and models participating in Phase 2 of the APARC Quasi-Biennial Oscillation initiative (QBOi), EGUsphere [preprint], https://doi.org/10.5194/egusphere-2026-1165, 2026b.
Baldwin, M. P. and Dunkerton, T. J.: Stratospheric Harbingers of Anomalous Weather Regimes, Science, 294, 581–584, https://doi.org/10.1126/science.1063315, 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, https://doi.org/10.1029/1999RG000073, 2001.
Baldwin, M. P., Ayarzagüena, B., Birner, T., Butchart, N., Butler, A. H., Charlton-Perez, A. J., Domeisen, D. I. V., Garfinkel, C. I., Garny, H., Gerber, E. P., Hegglin, M. I., Langematz, U., and Pedatella, N. M.: Sudden stratospheric warmings, Rev. Geophys., 59, e2020RG000708, https://doi.org/10.1029/2020RG000708, 2021.
Bjerknes, J.: Atmospheric teleconnections from the equatorial Pacific, Mon. Weather Rev., 97, 163–172, https://doi.org/10.1175/1520-0493(1969)097<0163:ATFTEP>2.3.CO;2, 1969.
Boer, G. J. and Hamilton, K.: QBO influence on extratropical predictive skill, Clim. Dynam., 31, 987–1000, https://doi.org/10.1007/s00382-008-0379-5, 2008.
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., Smith, A. K., Stockdale, T. N., Versick, S., 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., 148, 1459–1489, https://doi.org/10.1002/qj.3765, 2022.
Butchart, N. and Anstey, J. A.: Quasi-Biennial Oscillation, in: Encyclopedia of Atmospheric Sciences, Vol. 4, edited by: Robinson, W. A., Elsevier Academic Press, 536–545, https://doi.org/10.1016/B978-0-323-96026-7.00083-7, 2026.
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., Andrews, M. B., and Jones, C. D.: QBO phase synchronization in CMIP6 historical simulations attributed to ozone forcing, Geophys. Res. Lett., 50, e2023GL104401, https://doi.org/10.1029/2023GL104401, 2023.
Butler, A. H., Charlton-Perez, A., Domeisen, D. I. V., Simpson, I. R., and Sjoberg, J.: Predictability of Northern Hemisphere final stratospheric warmings and their surface impacts, Geophys. Res. Lett., 46, 10578–10588, https://doi.org/10.1029/2019GL083346, 2019.
Butler, A. H. and Gerber, E. P.: Optimizing the definition of a sudden stratospheric warming, J. Climate, 31, 2337–2349, https://doi.org/10.1175/JCLI-D-17-0648.1, 2018.
Cassou, C.: Intraseasonal interaction between the Madden-Julian Oscillation and the North Atlantic Oscillation, Nature, 455, 523–527, https://doi.org/10.1038/nature07286, 2008.
Charlton, A. J. and Polvani, L. M.: A New Look at Stratospheric Sudden Warmings. Part I: Climatology and Modeling Benchmarks, J. Climate, 20, 449–469, https://doi.org/10.1175/JCLI3996.1, 2007.
Choi, W. and Kim, K. Y.: Summertime variability of the western North Pacific subtropical high and its synoptic influences on the East Asian weather, Sci. Rep., 9, 7865, https://doi.org/10.1038/s41598-019-44414-w, 2019.
Domeisen, D. I. V., Garfinkel, C. I., and Butler, A. H.: The teleconnection of El Niño Southern Oscillation to the stratosphere, Rev. Geophys., 57, 5–47, https://doi.org/10.1029/2018RG000596, 2019.
Dunkerton, T. J.: The role of gravity waves in the quasi-biennial oscillation, J. Geophys. Res., 102, 26053–26076, https://doi.org/10.1029/96JD02999, 1997.
Eade, R., Smith, D., Scaife, A., Wallace, E., Dunstone, N., Hermanson, L., and Robinson, N.: Do seasonal-to-decadal climate predictions underestimate the predictability of the real world?, Geophys. Res. Lett., 41, 5620–5628, https://doi.org/10.1002/2014GL061146, 2014.
Ebdon, R. A.: The Quasi-Biennial Oscillation and its association with tropospheric circulation patterns, Meteorol. Mag., 104, 282–297, 1975.
Elsbury, D., Butler, A., Peings, Y., and Magnusdottir, G.: Sensitivity of Easterly QBO's Boreal Winter Teleconnections and Surface Impacts to SSWs, J. Climate, 37, 3675–3688, https://doi.org/10.1175/JCLI-D-23-0395.1, 2024.
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, Weather Clim. Dynam., 7, 317–339, https://doi.org/10.5194/wcd-7-317-2026, 2026.
García-Franco, J. L., Gray, L. J., Osprey, S., Jaison, A. M., Chadwick, R., and Lin, J.: Understanding the mechanisms for tropical surface impacts of the quasi-biennial oscillation (QBO), J. Geophys. Res.-Atmos., 128, e2023JD038474, https://doi.org/10.1029/2023JD038474, 2023.
García-Franco, J. L., Gray, L. J., Osprey, S., Chadwick, R., and Martin, Z.: The tropical route of quasi-biennial oscillation (QBO) teleconnections in a climate model, Weather Clim. Dynam., 3, 825–844, https://doi.org/10.5194/wcd-3-825-2022, 2022.
Garfinkel, C. I. and Hartmann, D. L.: The Influence of the Quasi-Biennial Oscillation on the Troposphere in Winter in a Hierarchy of Models. Part I: Simplified Dry GCMs, J. Atmos. Sci., 68, 1273–1289, https://doi.org/10.1175/2011JAS3665.1, 2011a.
Garfinkel, C. I. and Hartmann, D. L.: The Influence of the Quasi-Biennial Oscillation on the Troposphere in Winter in a Hierarchy of Models, Part II: Perpetual Winter WACCM Runs, J. Atmos. Sci., 68, 2026–2041, https://doi.org/10.1175/2011JAS3702.1, 2011b.
Garfinkel, C. I., Shaw, T. A., Hartmann, D. L., and Waugh, D. W.: Does the Holton–Tan Mechanism Explain How the Quasi-Biennial Oscillation Modulates the Arctic Polar Vortex?, J. Atmos. Sci., 69, 1713–1733, https://doi.org/10.1175/JAS-D-11-0209.1, 2012.
Garfinkel, C. I., Knight, J., Taguchi, M., Schwartz, C., Cohen, J., Chen, W., Butler, A. H., and Domeisen, D. I. V.: Development of the signal-to-noise paradox in subseasonal forecasting models: When? Where? Why?, Q. J. Roy. Meteor. Soc., 150, 4417–4436, https://doi.org/10.1002/qj.4822, 2024.
Garfinkel, C. I., Avisar, D., Osprey, S., and Smith, D.: The response of the QBO to external forcings: Implications for disruption events, J. Geophys. Res.-Atmos., 130, e2025JD044438, https://doi.org/10.1029/2025JD044438, 2025.
Gray, L. J., Crooks, S., Pascoe, C., Sparrow, S., and Palmer, M.: Solar and QBO influences on the timing of stratospheric sudden warmings, J. Atmos. Sci., 61, 2777–2796, https://doi.org/10.1175/JAS-3297.1, 2004.
Gray, L. J., Anstey, J. A., Kawatani, Y., Lu, H., Osprey, S., and Schenzinger, V.: Surface impacts of the Quasi Biennial Oscillation, Atmos. Chem. Phys., 18, 8227–8247, https://doi.org/10.5194/acp-18-8227-2018, 2018.
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., de Rosnay, P., 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.
Hitchcock, P., Butler, A., Charlton-Perez, A., Garfinkel, C. I., Stockdale, T., Anstey, J., Mitchell, D., Domeisen, D. I. V., Wu, T., Lu, Y., Mastrangelo, D., Malguzzi, P., Lin, H., Muncaster, R., Merryfield, B., Sigmond, M., Xiang, B., Jia, L., Hyun, Y.-K., Oh, J., Specq, D., Simpson, I. R., Richter, J. H., Barton, C., Knight, J., Lim, E.-P., and Hendon, H.: Stratospheric Nudging And Predictable Surface Impacts (SNAPSI): a protocol for investigating the role of stratospheric polar vortex disturbances in subseasonal to seasonal forecasts, Geosci. Model Dev., 15, 5073–5092, https://doi.org/10.5194/gmd-15-5073-2022, 2022.
Hitchman, M. H., Yoden, S., Haynes, P. H., Kumar, V., and Tegtmeier, S.: An observational history of the direct influence of the stratospheric quasi-biennial oscillation on the tropical and subtropical upper troposphere and lower stratosphere, J. Meteorol. Soc. Jpn., 99, 239–267, https://doi.org/10.2151/jmsj.2021-012, 2021.
Holt, L. A., Lott, F., Garcia, R. R., Kiladis, G. N., Cheng, Y.-M., 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., Yoshida, K., and Yukimoto, S.: An evaluation of tropical waves and wave forcing of the QBO in the QBOi models, Q. J. Roy. Meteor. Soc., 148, 1541–1567, https://doi.org/10.1002/qj.3827, 2022.
Holton, J. R. and Lindzen, R. S.: An Updated Theory for the Quasi-Biennial Cycle of the Tropical Stratosphere, J. Atmos. Sci., 29, 1076–1080, https://doi.org/10.1175/1520-0469(1972)029<1076:AUTFTQ>2.0.CO;2, 1972.
Holton, J. and Tan, H.: The Influence of the Equatorial Quasi-Biennial Oscillation on the Global Circulation at 50 mb, J. Atmos. Sci., 37, 2200–2208, https://doi.org/10.1175/1520-0469(1980)037<2200:TIOTEQ>2.0.CO;2, 1980.
Holton, J. and Tan, H.: The Quasi-Biennial Oscillation in the Northern Hemisphere Lower Stratosphere, J. Meteorol. Soc. Jpn., 60, 140–148, https://doi.org/10.2151/jmsj1965.60.1_140, 1982.
Hu, J., Ren, R., and Xu, H.: Occurrence of winter stratospheric sudden warming events and the seasonal timing of spring stratospheric final warming, J. Atmos. Sci., 71, 2319–2334, https://doi.org/10.1175/JAS-D-13-0349.1, 2014.
Hunt, K. M. R. and Zaz, S. N.: Linking the North Atlantic Oscillation to winter precipitation over the Western Himalaya through disturbances of the subtropical jet, Clim. Dyn., 60, 2389–2403, https://doi.org/10.1007/s00382-022-06450-7, 2023.
Hurrell, J. W., Kushnir, Y., Ottersen, G., and Visbeck, M.: The North Atlantic Oscillation: Climate significance and environmental impact, Geoph. Monog. Series, 134, 1–36, https://doi.org/10.1029/134GM01, 2003.
Karami, K., Garcia, R., Jacobi, C., Richter, J. H., and Tilmes, S.: The Holton–Tan mechanism under stratospheric aerosol intervention, Atmos. Chem. Phys., 23, 3799–3818, https://doi.org/10.5194/acp-23-3799-2023, 2023.
Kawatani, Y., Watanabe, S., Sato, K., Dunkerton, T. J., 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, 2010.
Kawatani, Y., Hamilton, K., Watanabe, S., Taguchi, M., Serva, F., Anstey, J. A., Richter, J. H., Butchart, N., Orbe, C., Osprey, S. M., Naoe, H., Elsbury, D., Chen, C.-C., García-Serrano, J., Glanville, A., Kerzenmacher, T., Lott, F., Palmeiro, F. M., Park, M., Versick, S., and Yoshida, K.: QBOi El Niño–Southern Oscillation experiments: overview of the experimental design and ENSO modulation of the QBO, Weather Clim. Dynam., 6, 1045–1073, https://doi.org/10.5194/wcd-6-1045-2025, 2025.
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.
Kumar, V., Yoden, S., and Hitchman, M. H.: QBO and ENSO effects on the mean meridional circulation, polar vortex, subtropical westerly jets, and wave patterns during boreal winter, J. Geophys. Res.-Atmos., 127, e2022JD036691, https://doi.org/10.1029/2022JD036691, 2022.
Kumar, V., Hitchman, M. H., Du, W., Dhaka, S. K., and Yoden, S.: Teleconnection of the Quasi-Biennial Oscillation with boreal winter surface climate in Eurasia and North America, Communications Earth & Environment, 5, 251, https://doi.org/10.1038/s43247-024-01422-7, 2024.
Labitzke, K.: On the interannual variability of the middle stratosphere during the northern winters, J. Meteorol. Soc. Jpn., 60, 124–139, https://doi.org/10.2151/jmsj1965.60.1_124, 1982.
Lee, R. W., Woolnough, S. J., Charlton-Perez, A. J., and Vitart, F.: ENSO modulation of MJO teleconnections to the North Atlantic and Europe, Geophys. Res. Lett., 46, 13535–13545, https://doi.org/10.1029/2019GL084683, 2019.
Lee, S. S., Seo, Y. W., Ha, K. J., and Jhun, J. G.: Impact of the western North Pacific subtropical high on the East Asian monsoon precipitation and the Indian Ocean precipitation in the boreal summertime, Asia-Pac. J. Atmos. Sci., 49, 171–182, https://doi.org/10.1007/s13143-013-0018-x, 2013.
Lindzen, R. S. and Holton, J. R.: A Theory of the Quasi-Biennial Oscillation, J. Atmos. Sci., 25, 1095–1107, https://doi.org/10.1175/1520-0469(1968)025<1095:ATOTQB>2.0.CO;2, 1968.
Lu, H., Bracegirdle, T. J., Phillips, T., Bushell, A., and Gray, L. J.: Mechanisms for the Holton–Tan relationship and its decadal variation, J. Geophys. Res.-Atmos., 119, 2811–2830, https://doi.org/10.1002/2013JD021352, 2014.
Lu, H., Hitchman, M. H., Gray, L. J., Anstey, J. A., and Osprey, S. M.: On the role of Rossby wave breaking in the quasi-biennial modulation of the stratospheric polar vortex during boreal winter, Q. J. Roy. Meteor. Soc., 146, 1939–1959, https://doi.org/10.1002/qj.3775, 2020.
Madden, R. A. and Julian, P. R.: Observations of the 40–50-Day Tropical Oscillation: A Review, Mon. Weather Rev., 122, 814–837, https://doi.org/10.1175/1520-0493(1994)122<0814:OOTDTO>2.0.CO;2, 1994.
Naoe, H., García-Franco, J. L., Park, C.-H., Rodrigo, M., Palmeiro, F. M., Serva, F., Taguchi, M., Yoshida, K., Anstey, J. A., García-Serrano, J., Son, S.-W., Kawatani, Y., Butchart, N., Hamilton, K., Chen, C.-C., Glanville, A., Kerzenmacher, T., Lott, F., Orbe, C., Osprey, S., Park, M., Richter, J. H., Versick, S., and Watanabe, S.: QBOi El Niño–Southern Oscillation experiments: teleconnections of the QBO, Weather Clim. Dynam., 6, 1419–1442, https://doi.org/10.5194/wcd-6-1419-2025, 2025.
O'Reilly, C. H., Weisheimer, A., Woollings, T., Gray, L. J., and MacLeod, D.: The importance of stratospheric initial conditions for winter North Atlantic Oscillation predictability and implications for the signal-to-noise paradox, Q. J. Roy. Meteor. Soc., 145, 131–146, https://doi.org/10.1002/qj.3413, 2019.
Palmeiro, F. M., Barriopedro, D., García-Herrera, R., and Calvo, N.: Comparing Sudden Stratospheric Warming Definitions in Reanalysis Data, J. Climate, 28, 6823–6840, https://doi.org/10.1175/JCLI-D-15-0004.1, 2015.
Palmeiro, F. M., Iza, M., Barriopedro, D., Calvo, N., and García-Herrera, R.: The complex behavior of El Niño winter 2015–2016, Geophys. Res. Lett., 44, 2902–2910, https://doi.org/10.1002/2017GL072920, 2017.
Park, C.-H., Son, S.-W., Lim, Y., and Choi, J.: Quasi-biennial oscillation-related surface air temperature change over the western North Pacific in late winter, Int. J. Climatol., 42, 4351–4359, https://doi.org/10.1002/joc.7470, 2022.
Plumb, R. A. and Bell, R. C.: A model of the quasi-biennial oscillation on an equatorial beta-plane, Q. J. Roy. Meteor. Soc., 108, 335–352, https://doi.org/10.1002/qj.49710845604, 1982.
Rao, J., Garfinkel, C. I., and White, I. P.: Impact of the Quasi-Biennial Oscillation on the Northern Winter Stratospheric Polar Vortex in CMIP5/6 Models, J. Climate, 33, 4787–4813, https://doi.org/10.1175/JCLI-D-19-0663.1, 2020.
Rao, J., Garfinkel, C. I., and White, I. P.: Development of the Extratropical Response to the Stratospheric Quasi-Biennial Oscillation, J. Climate, 34, 7239–7255, https://doi.org/10.1175/JCLI-D-20-0960.1, 2021.
Reed, R. J., Campbell, W. J., Rasmussen, L. A., and Rogers, D. G.: Evidence of a downward-propagating annual wind reversal in the equatorial stratosphere, J. Geophys. Res., 66, 813–818, https://doi.org/10.1029/JZ066i003p00813, 1961.
Richter, J. H., Butchart, N., Kawatani, Y., Bushell, A. C., Holt, L., Serva, F., Anstey, J. A., Simpson, I. R., Osprey, S., 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., 148, 1490–1518, https://doi.org/10.1002/qj.3749, 2022.
Scaife, A. A., Athanassiadou, M., Andrews, M., Arribas, A., Baldwin, M., Dunstone, N., Knight, J., MacLachlan, C., Manzini, E., Müller, W. A., Pohlmann, H., Smith, D., Stockdale, T., and Williams, A.: Predictability of the quasi-biennial oscillation and its northern winter teleconnection on seasonal to decadal timescales, Geophys. Res. Lett., 41, 1752–1758, https://doi.org/10.1002/2013GL059160, 2014.
Scherhag, R.: Die explosionsartige Stratosphärenerwärmung des Spätwinters 1951/52, Ber. Dtsch. Wetterd., 38, 51–63, 1952.
Seo, J., Choi, W., Youn, D., Park, D.-S. R. and Kim, J. Y.: Relationship between the Stratospheric Quasi-Biennial Oscillation and the Spring Rainfall in the Western North Pacific, Geophys. Res. Lett., 40, 5949–5953, https://doi.org/10.1002/2013GL058266, 2013.
Serva, F., Anstey, J. A., Bushell, A. C., Butchart, N., Cagnazzo, C., Gray, L. J., Kawatani, Y., Osprey, S. M., Richter, J. H., and Simpson, I. R.: The impact of the QBO on the region of the tropical tropopause in QBOi models: Present-day simulations, Q. J. Roy. Meteor. Soc., 148, 1945–1964, https://doi.org/10.1002/qj.4287, 2022.
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., 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., 148, 1519–1540, https://doi.org/10.1002/qj.3919, 2022.
Taylor, K. E., Stouffer, R. J., and Meehl, G. A.: An Overview of CMIP5 and the Experiment Design, B. Am. Meteorol. Soc., 93, 485–498, https://doi.org/10.1175/BAMS-D-11-00094.1, 2012.
Thiéblemont, R., Ayarzagüena, B., Matthes, K., Bekki, S., Abalichin, J., and Langematz, U.: Drivers and surface signal of interannual variability of boreal stratospheric final warmings, J. Geophys. Res.-Atmos., 124, 5400–5417, https://doi.org/10.1029/2018JD029852, 2019.
Thompson, D. W. J. and Wallace, J. M.: Regional climate impacts of the Northern Hemisphere annular mode, Science, 293, 85–89, https://doi.org/10.1126/science.1058958, 2001.
Trenberth, K. E.: The definition of El Niño, B. Am. Meteorol. Soc., 78, 2771–2777, https://doi.org/10.1175/1520-0477(1997)078<2771:TDOENO>2.0.CO;2, 1997.
Veryard, R. G. and Ebdon, R. A.: Fluctuations in Tropical Stratospheric Winds, Meteorol. Mag., 90, 125–143, 1961.
Wan, T., Wang, L., Son, S.-W., Lu, Y., Shen, X., and Park, C.-H.: The Arctic Oscillation response to the QBO in an EOF-based QBO phase space, J. Meteorol. Res., 39, 933–944, https://doi.org/10.1007/s13351-025-5026-0, 2025.
Yamazaki, K., Nakamura, T., Ukita, J., and Hoshi, K.: A tropospheric pathway of the stratospheric quasi-biennial oscillation (QBO) impact on the boreal winter polar vortex, Atmos. Chem. Phys., 20, 5111–5127, https://doi.org/10.5194/acp-20-5111-2020, 2020.
Yoden, S., Kumar, V., Dhaka, S. K., and Hitchman, M. H.: Global monsoon systems and their modulation by the equatorial Quasi-Biennial Oscillation, Mausam, 74, 239–252, https://doi.org/10.54302/mausam.v74i2.5948, 2023.
Short summary
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.
The observed winds in the upper atmosphere over the equator have alternating easterly and...
