Articles | Volume 7, issue 3
https://doi.org/10.5194/wcd-7-1405-2026
© 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-7-1405-2026
© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
17 Aug 2026
Research article | Highlight paper |
| 17 Aug 2026
| 17 Aug 2026
Forecast-based attribution of the role of stratospheric variability in weather extremes
William J. M. Seviour
CORRESPONDING AUTHOR
Department of Mathematics and Statistics, University of Exeter, Exeter, UK
Justin Finkel
Data Science Institute and Department of Geophysical Sciences, University of Chicago, Chicago, IL, USA
Philip Rupp
Meteorological Institute Munich, Ludwig-Maximilians University, Munich, Germany
Regan Mudhar
Department of Mathematics and Statistics, University of Exeter, Exeter, UK
Institute of Earth Surface Dynamics, Université de Lausanne, Lausanne, Switzerland
Amy H. Butler
NOAA Chemical Sciences Laboratory, Boulder, CO, USA
Chaim I. Garfinkel
Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University, Jerusalem, Israel
Peter Hitchcock
Department of Earth and Atmospheric Sciences, Cornell University, Ithaca, NY, USA
Blanca Ayarzagüena
Department of Earth Physics and Astrophysics, Facultad de CC. Físicas, Universidad Complutense Madrid, Madrid, Spain
Dong-Chan Hong
School of Earth and Environmental Sciences, Seoul National University, Seoul, Republic of Korea
Yu-Kyung Hyun
National Institute of Meteorological Sciences, Korea Meteorological Administration, Jeju, Republic of Korea
Department of Atmospheric Sciences, University of Washington, Seattle, WA, USA
Eun-Pa Lim
Bureau of Meteorology, Melbourne, Australia
Daniel De Maeseneire
Department of Earth Physics and Astrophysics, Facultad de CC. Físicas, Universidad Complutense Madrid, Madrid, Spain
Gabriele Messori
Department of Earth Sciences, Uppsala University, Uppsala, Sweden
Swedish Centre for Impacts of Climate Extremes (climes), Uppsala University, Uppsala, Sweden
Department of Meteorology, Stockholm University, Stockholm, Sweden
Gerbrand Koren
Copernicus Institute of Sustainable Development, Utrecht University, Utrecht, the Netherlands
Michael Sigmond
Canadian Centre for Climate Modelling and Analysis, Environment and Climate Change Canada, Victoria, British Columbia, Canada
Isla R. Simpson
NSF National Center for Atmospheric Research, Boulder, CO, USA
Seok-Woo Son
School of Earth and Environmental Sciences, Seoul National University, Seoul, Republic of Korea
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Understanding impacts of climate extremes is very important for society and the economy. We identify three challenges restricting this understanding: limited availability and quality of impact data, difficulties in understanding why given impacts occur and lack of reliable projections of future impacts. We also identify key opportunities, including newly released datasets, recent methodological and technical advances and interdisciplinary collaborations between the social and natural sciences.
Blanca Ayarzagüena, Amy H. Butler, Peter Hitchcock, Chaim I. Garfinkel, Zac D. Lawrence, Wuhan Ning, Philip Rupp, Zheng Wu, Hilla Afargan-Gerstman, Natalia Calvo, Alvaro de la Cámara, Martin Jucker, Gerbrand Koren, Daniel De Maeseneire, Gloria L. Manney, Marisol Osman, Masakazu Taguchi, Cory Barton, Dong-Chan Hong, Yu-Kyung Hyun, Hera Kim, Jeff Knight, Piero Malguzzi, Daniele Mastrangelo, Jiyoung Oh, Inna Polichtchouk, Jadwiga H. Richter, Isla R. Simpson, Seok-Woo Son, Damien Specq, and Tim Stockdale
Weather Clim. Dynam., 7, 411–437, https://doi.org/10.5194/wcd-7-411-2026, https://doi.org/10.5194/wcd-7-411-2026, 2026
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Sudden Stratospheric Warmings (SSWs) are known to follow a sustained wave dissipation in the stratosphere, which depends on both the tropospheric and stratospheric states. However, the relative role of each state is still unclear. Using a new set of subseasonal to seasonal forecasts, we show that the stratospheric state does not drastically affect the precursors of three recent SSWs, but modulates the stratospheric wave activity, with impacts depending on SSW features.
Martin B. Andrews, Neal Butchart, James A. Anstey, Ewa Bednarz, Dillon Elsbury, Jorge L. García-Franco, Vinay Kumar, Froila M. Palmeiro, Natasha E. Trencham, Kohei Yoshida, Zhaoyang Chai, Dong-Chan Hong, Kai Huang, Aleena M. Jaison, Yoshio Kawatani, Jeff R. Knight, Pu Lin, François Lott, Yixiong Lu, Hiroaki Naoe, Scott M. Osprey, Jadwiga H. Richter, Federico Serva, Seok-Woo Son, Qi Tang, Shingo Watanabe, and Jinbo Xie
EGUsphere, https://doi.org/10.5194/egusphere-2026-737, https://doi.org/10.5194/egusphere-2026-737, 2026
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The observed winds in the upper atmosphere over the equator have alternating easterly and westerly regions that descend towards the lower atmosphere before dissipating, with a period of approximately 28 months. This is known as the Quasi-Biennial Oscillation (QBO). The QBO is known to influence remote regions of the atmosphere. This paper details the results of multi-model experiments where the QBO is nudged towards the observed QBO allowing the assessment of these remote connections.
Dillon Elsbury, Federico Serva, Julie M. Caron, Seung-Yoon Back, Clara Orbe, Jadwiga H. Richter, James A. Anstey, Neal Butchart, Chih-Chieh Chen, Javier García-Serrano, Anne Glanville, Yoshio Kawatani, Tobias Kerzenmacher, Francois Lott, Hiroaki Naoe, Scott Osprey, Froila M. Palmeiro, Seok-Woo Son, Masakazu Taguchi, Stefan Versick, Shingo Watanabe, and Kohei Yoshida
Weather Clim. Dynam., 7, 317–339, https://doi.org/10.5194/wcd-7-317-2026, https://doi.org/10.5194/wcd-7-317-2026, 2026
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We used climate models to test how constant El Niño and La Niña ocean conditions shape the Madden-Julian Oscillation during northern winter. El Niño made this weather pattern move faster, while La Niña slowed it down. The Quasi-Biennial Oscillation, a repeating wind pattern high in the atmosphere, had little effect. This shows that long-lasting ocean conditions mainly drive the changes we found.
Ninghui Li, Jonathon S. Wright, Philip Rupp, Alison Ming, Shenglong Zhang, and Jie Gao
EGUsphere, https://doi.org/10.5194/egusphere-2026-558, https://doi.org/10.5194/egusphere-2026-558, 2026
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We study the Asian summer monsoon anticyclone, a high-altitude system critical to Asian summer weather. Global data analysis over two decades reveals three stable centers (instead of a single vortex), wind/water vapor heat drivers, and the process of west/east propagation and dissipation.
Alok Kumar Samantaray and Gabriele Messori
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2025-646, https://doi.org/10.5194/essd-2025-646, 2026
Revised manuscript under review for ESSD
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We present a global dataset that links drought events to human and economic exposure and impacts. Using a two-step approach, we first cluster drought events from precipitation and temperature records to track their severity and extent, and then connect them to population and Gross Domestic Product exposure and to impacts reported in disaster databases. The dataset supports risk planning and mitigation efforts.
Wuhan Ning, Chaim I. Garfinkel, Judah Cohen, Ian P. White, and Jian Rao
Weather Clim. Dynam., 7, 277–295, https://doi.org/10.5194/wcd-7-277-2026, https://doi.org/10.5194/wcd-7-277-2026, 2026
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Whether the zonal structure of a polar vortex matters for surface climate is an open question, with much observational work showing a role but with limited modeling work and demonstration of a causal influence. Here, we isolate this influence using a moist general circulation model. We find that the surface responses differ qualitatively depending on the zonal asymmetries of the shifted polar vortex and concurrently occurring wave reflection events, and provide a mechanistic explanation for why.
Ewa M. Bednarz, Amy H. Butler, James M. Haywood, Matthew Henry, Andy Jones, Ben Kravitz, Walker R. Lee, Douglas G. MacMartin, Amanda C. Maycock, Takashi Sekiya, Shingo Watanabe, and Daniele Visioni
EGUsphere, https://doi.org/10.5194/egusphere-2026-310, https://doi.org/10.5194/egusphere-2026-310, 2026
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An assessment of the potential impacts of Stratospheric Aerosol Injection, a proposed method to offset global warming, on stratospheric ozone projections over the 21st century using the new multi-model GeoMIP G6-1.5K-SAI experiment. We discuss drivers of the responses, identify areas of model agreement and disagreement and sources of uncertainty. Our results highlight the need to assess any projected SAI impacts in wider strategy and scenario dimension using a multi-model framework.
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
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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.
Jingyu Wang, Gabriel Chiodo, Blanca Ayarzagüena, William T. Ball, Mohamadou Diallo, Birgit Hassler, James Keeble, Peer Nowack, Clara Orbe, Sandro Vattioni, and Timofei Sukhodolov
Atmos. Chem. Phys., 25, 17819–17844, https://doi.org/10.5194/acp-25-17819-2025, https://doi.org/10.5194/acp-25-17819-2025, 2025
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We analyzed the ozone response under elevated CO2 using the data from CMIP6 DECK experiments. We then examined the relations between ozone response and changes in temperature and circulation to identify the drivers of ozone change. The climate feedback of ozone is investigated through offline calculations and by comparing models with and without interactive chemistry. We find that ozone–climate interactions are important for Earth system models and thus should be considered in future model development.
Alexey Yu. Karpechko, Amy H. Butler, and Frederic Vitart
Weather Clim. Dynam., 6, 1661–1681, https://doi.org/10.5194/wcd-6-1661-2025, https://doi.org/10.5194/wcd-6-1661-2025, 2025
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We study how the knowledge of future tropical and stratospheric conditions could improve forecasts in winter remotely, via teleconnections, 3–6 weeks ahead. We find that the tropics improve forecasts of sea level pressure in subtropics, Europe, and North America. The stratosphere improves forecasts in high latitudes and Europe. Improvements are small for temperature and precipitation. Larger forecast ensembles than usually available for research are needed to predict teleconnection signals.
Sara Lindersson and Gabriele Messori
Earth Syst. Sci. Data, 17, 6379–6403, https://doi.org/10.5194/essd-17-6379-2025, https://doi.org/10.5194/essd-17-6379-2025, 2025
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The study of past temperature-related disasters requires information on socioeconomic impacts, hazard intensity and human exposure. This is often lacking in current disaster databases. Our dataset fills this gap by integrating impact records with information on disaster locations, high-resolution meteorological data, and population estimates. Covering 382 disasters in 71 countries (1979–2018), this dataset enables deeper analyses of heat-related risk and vulnerabilities.
Sebastian H. M. Hickman, Makoto M. Kelp, Paul T. Griffiths, Kelsey Doerksen, Kazuyuki Miyazaki, Elyse A. Pennington, Gerbrand Koren, Fernando Iglesias-Suarez, Martin G. Schultz, Kai-Lan Chang, Owen R. Cooper, Alex Archibald, Roberto Sommariva, David Carlson, Hantao Wang, J. Jason West, and Zhenze Liu
Geosci. Model Dev., 18, 8777–8800, https://doi.org/10.5194/gmd-18-8777-2025, https://doi.org/10.5194/gmd-18-8777-2025, 2025
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Machine learning is being more widely used across environmental and climate science. This work reviews the use of machine learning in tropospheric ozone research, focusing on three main application areas in which significant progress has been made. Common challenges in using machine learning across the three areas are highlighted, and future directions for the field are indicated.
Hiroaki Naoe, Jorge L. García-Franco, Chang-Hyun Park, Mario Rodrigo, Froila M. Palmeiro, Federico Serva, Masakazu Taguchi, Kohei Yoshida, James A. Anstey, Javier García-Serrano, Seok-Woo Son, Yoshio Kawatani, Neal Butchart, Kevin Hamilton, Chih-Chieh Chen, Anne Glanville, Tobias Kerzenmacher, François Lott, Clara Orbe, Scott Osprey, Mijeong Park, Jadwiga H. Richter, Stefan Versick, and Shingo Watanabe
Weather Clim. Dynam., 6, 1419–1442, https://doi.org/10.5194/wcd-6-1419-2025, https://doi.org/10.5194/wcd-6-1419-2025, 2025
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Links between the stratospheric Quasi-Biennial Oscillation (QBO) and atmospheric circulations in the tropics, subtropics, and polar regions, as well as their modulation by the El Nino–Southern Oscillation, are examined through model experiments. The QBO–polar vortex connection is reproduced by a multi-model ensemble at about half the observed amplitude. Weak performance of QBO signals in these regions is likely due to unrealistically weak QBO amplitudes in the lower stratosphere.
Marco M. Lehmann, Josie Geris, Ilja van Meerveld, Daniele Penna, Youri Rothfuss, Matteo Verdone, Pertti Ala-Aho, Matyas Arvai, Alise Babre, Philippe Balandier, Fabian Bernhard, Lukrecija Butorac, Simon D. Carrière, Natalie C. Ceperley, Zuosinan Chen, Alicia Correa, Haoyu Diao, David Dubbert, Maren Dubbert, Fabio Ercoli, Marius G. Floriancic, Alligin Ghazoul, Teresa E. Gimeno, Damien Gounelle, Frank Hagedorn, Christophe Hissler, Frédéric Huneau, Alberto Iraheta, Tamara Jakovljević, Nerantzis Kazakis, Zoltan Kern, Laura Kinzinger, Karl Knaebel, Johannes Kobler, Jiri Kocum, Charlotte Koeber, Gerbrand Koren, Angelika Kübert, Dawid Kupka, Samuel Le Gall, Aleksi Lehtonen, Thomas Leydier, Philippe Malagoli, Francesca Sofia Manca di Villahermosa, Chiara Marchina, Núria Martínez-Carreras, Nicolas Martin-StPaul, Hannu Marttila, Aline Meyer Oliveira, Gael Monvoisin, Natalie Orlowski, Kadi Palmik-Das, Aurel Persoiu, Andrei Popa, Egor Prikaziuk, Cécile Quantin, Katja T. Rinne-Garmston, Clara Rohde, Martin Sanda, Matthias Saurer, Daniel Schulz, Michael P. Stockinger, Christine Stumpp, Jean-Stéphane Vénisse, Lukas Vlcek, Stylianos Voudouris, Björn Weeser, Mark E. Wilkinson, Giulia Zuecco, and Katrin Meusburger
Earth Syst. Sci. Data, 17, 6129–6147, https://doi.org/10.5194/essd-17-6129-2025, https://doi.org/10.5194/essd-17-6129-2025, 2025
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This study describes a unique large-scale isotope dataset to study water dynamics in European forests. Researchers collected data from 40 beech and spruce forest sites in spring and summer 2023, using a standardized method to ensure consistency. The results show that water sources for trees change between seasons and vary by tree species. This large dataset offers valuable information for understanding plant water use, improving ecohydrological models, and mapping water cycles across Europe.
Kai Kornuber, Emanuele Bevacqua, Mariana Madruga de Brito, Wiebke S. Jäger, Pauline Rivoire, Cassandra D. W. Rogers, Fabiola Banfi, Fulden Batibeniz, James Carruthers, Carlo de Michele, Silvia de Angeli, Cristina Deidda, Marleen C. de Ruiter, Andreas H. Fink, Henrique M. D. Goulart, Katharina Küpfer, Patrick Ludwig, Douglas Maraun, Gabriele Messori, Shruti Nath, Fiachra O’Loughlin, Joaquim G. Pinto, Benjamin Poschlod, Alexandre M. Ramos, Colin Raymond, Andreia F. S. Ribeiro, Deepti Singh, Laura Suarez Gutierrez, Philip J. Ward, and Christopher J. White
EGUsphere, https://doi.org/10.5194/egusphere-2025-4683, https://doi.org/10.5194/egusphere-2025-4683, 2025
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Impacts from extreme weather events are becoming increasingly severe under global warming, in particular when events occur simultaneously or successively. While these complex event combinations are often difficult to analyse as impact data, early warning schemes or modelling frameworks might not be fit for purpose. In this perspective we reflect on the usability of compound event research to bridge the gap between academic research and real-world applications, by formulating a set of guidelines.
Philip Rupp, Liliana Vázquez Fernández, William J. M. Seviour, and Thomas Birner
EGUsphere, https://doi.org/10.5194/egusphere-2025-4587, https://doi.org/10.5194/egusphere-2025-4587, 2025
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This study examines mortality impacts of sudden stratospheric warming events (SSWs). SSWs persistently increase the chance for cold spells in Northern Europe, but their direct socio-economic effects remain poorly quantified. Using ensemble simulations of the 2018 SSW and mortality records, we attribute ca. 750 deaths in the UK and 250 in the Nordics to this event. The strongest impacts emerge from the combination of post-SSW cold anomalies and heightened mortality sensitivity to these anomalies.
Cristiana Stan, Saisri Kollapaneni, Andrea M. Jenney, Jiabao Wang, Zheng Wu, Cheng Zheng, Hyemi Kim, Chaim I. Garfinkel, and Ayush Singh
Geosci. Model Dev., 18, 7969–7985, https://doi.org/10.5194/gmd-18-7969-2025, https://doi.org/10.5194/gmd-18-7969-2025, 2025
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The diagnostics package is an open-source Python software package used for evaluating the Madden–Julian Oscillation teleconnections to the extratropics, as predicted by subseasonal-to-seasonal (S2S) forecast systems.
Sina Loriani, Yevgeny Aksenov, David I. Armstrong McKay, Govindasamy Bala, Andreas Born, Cristiano Mazur Chiessi, Henk A. Dijkstra, Jonathan F. Donges, Sybren Drijfhout, Matthew H. England, Alexey V. Fedorov, Laura C. Jackson, Kai Kornhuber, Gabriele Messori, Francesco S. R. Pausata, Stefanie Rynders, Jean-Baptiste Sallée, Bablu Sinha, Steven C. Sherwood, Didier Swingedouw, and Thejna Tharammal
Earth Syst. Dynam., 16, 1611–1653, https://doi.org/10.5194/esd-16-1611-2025, https://doi.org/10.5194/esd-16-1611-2025, 2025
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In this work, we draw on palaeo-records, observations, and modelling studies to review tipping points in the ocean overturning circulations, monsoon systems, and global atmospheric circulations. We find indications for tipping in the ocean overturning circulations and the West African monsoon, with potentially severe impacts on the Earth system and humans. Tipping in the other considered systems is regarded as conceivable but is currently not sufficiently supported by evidence.
John P. Dunne, Helene T. Hewitt, Julie M. Arblaster, Frédéric Bonou, Olivier Boucher, Tereza Cavazos, Beth Dingley, Paul J. Durack, Birgit Hassler, Martin Juckes, Tomoki Miyakawa, Matt Mizielinski, Vaishali Naik, Zebedee Nicholls, Eleanor O'Rourke, Robert Pincus, Benjamin M. Sanderson, Isla R. Simpson, and Karl E. Taylor
Geosci. Model Dev., 18, 6671–6700, https://doi.org/10.5194/gmd-18-6671-2025, https://doi.org/10.5194/gmd-18-6671-2025, 2025
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The seventh phase of the Coupled Model Intercomparison Project (CMIP7) coordinates efforts to answer key and timely climate science questions and facilitate delivery of relevant multi-model simulations for prediction and projection; characterization, attribution, and process understanding; and vulnerability, impact, and adaptation analysis. Key to the CMIP7 design are the mandatory Diagnostic, Evaluation and Characterization of Klima and optional Assessment Fast Track experiments.
Tamara Emmerichs, Abdulla Al Mamun, Lisa Emberson, Huiting Mao, Leiming Zhang, Limei Ran, Clara Betancourt, Anthony Wong, Gerbrand Koren, Giacomo Gerosa, Min Huang, and Pierluigi Guaita
Biogeosciences, 22, 4823–4849, https://doi.org/10.5194/bg-22-4823-2025, https://doi.org/10.5194/bg-22-4823-2025, 2025
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The risk of ozone pollution to plants is estimated based on the flux through the plant pores which still has uncertainties. In this study, we estimate this quantity with nine models at different land types worldwide, driven by measurement data. The models mostly estimated reasonable summertime ozone flux to plants. The model results varied by land cover, mainly related to the a lack of moisture in the soil. This work is an important step for assessing the ozone impact on vegetation.
Clare M. Flynn, Julia Moemken, Joaquim G. Pinto, Michael K. Schutte, and Gabriele Messori
Earth Syst. Sci. Data, 17, 4431–4453, https://doi.org/10.5194/essd-17-4431-2025, https://doi.org/10.5194/essd-17-4431-2025, 2025
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We created a new, publicly available, database of the top 50 most extreme European winter windstorms from each of four different meteorological input data sets covering the years 1995–2015. We found variability in all aspects of our database, from which storms were included in the top 50 storms for each input to the storms' spatial variability. We urge users of our database to consider the storms as identified from two or more input sources within our database where possible.
Benjamin M. Sanderson, Victor Brovkin, Rosie A. Fisher, David Hohn, Tatiana Ilyina, Chris D. Jones, Torben Koenigk, Charles Koven, Hongmei Li, David M. Lawrence, Peter Lawrence, Spencer Liddicoat, Andrew H. MacDougall, Nadine Mengis, Zebedee Nicholls, Eleanor O'Rourke, Anastasia Romanou, Marit Sandstad, Jörg Schwinger, Roland Séférian, Lori T. Sentman, Isla R. Simpson, Chris Smith, Norman J. Steinert, Abigail L. S. Swann, Jerry Tjiputra, and Tilo Ziehn
Geosci. Model Dev., 18, 5699–5724, https://doi.org/10.5194/gmd-18-5699-2025, https://doi.org/10.5194/gmd-18-5699-2025, 2025
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This study investigates how climate models warm in response to simplified carbon emissions trajectories, refining the understanding of climate reversibility and commitment. Metrics are defined for warming response to cumulative emissions and for the cessation of emissions or ramp-down to net-zero and net-negative levels. Results indicate that previous concentration-driven experiments may have overstated the Zero Emissions Commitment due to emissions rates exceeding historical levels.
Yunqian Zhu, Hideharu Akiyoshi, Valentina Aquila, Elizabeth Asher, Ewa M. Bednarz, Slimane Bekki, Christoph Brühl, Amy H. Butler, Parker Case, Simon Chabrillat, Gabriel Chiodo, Margot Clyne, Peter R. Colarco, Sandip Dhomse, Lola Falletti, Eric Fleming, Ben Johnson, Andrin Jörimann, Mahesh Kovilakam, Gerbrand Koren, Ales Kuchar, Nicolas Lebas, Qing Liang, Cheng-Cheng Liu, Graham Mann, Michael Manyin, Marion Marchand, Olaf Morgenstern, Paul Newman, Luke D. Oman, Freja F. Østerstrøm, Yifeng Peng, David Plummer, Ilaria Quaglia, William Randel, Samuel Rémy, Takashi Sekiya, Stephen Steenrod, Timofei Sukhodolov, Simone Tilmes, Kostas Tsigaridis, Rei Ueyama, Daniele Visioni, Xinyue Wang, Shingo Watanabe, Yousuke Yamashita, Pengfei Yu, Wandi Yu, Jun Zhang, and Zhihong Zhuo
Geosci. Model Dev., 18, 5487–5512, https://doi.org/10.5194/gmd-18-5487-2025, https://doi.org/10.5194/gmd-18-5487-2025, 2025
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To understand the climate impact of the 2022 Hunga volcanic eruption, we developed a climate model–observation comparison project. The paper describes the protocols and models that participate in the experiments. We designed several experiments to achieve our goals of this activity: (1) to evaluate the climate model performance and (2) to understand the Earth system responses to this eruption.
Ying Dai, Peter Hitchcock, Amy H. Butler, Chaim I. Garfinkel, and William J. M. Seviour
Weather Clim. Dynam., 6, 841–862, https://doi.org/10.5194/wcd-6-841-2025, https://doi.org/10.5194/wcd-6-841-2025, 2025
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Using a new database of subseasonal to seasonal (S2S) forecasts, we find that with a successful forecast of the sudden stratospheric warming (SSW), S2S models can capture the European precipitation signals after the 2018 SSW several weeks in advance. The findings indicate that the stratosphere represents an important source of S2S predictability for precipitation over Europe and call for consideration of stratospheric variability in hydrological prediction at S2S timescales.
Nathan P. Gillett, Isla R. Simpson, Gabi Hegerl, Reto Knutti, Dann Mitchell, Aurélien Ribes, Hideo Shiogama, Dáithí Stone, Claudia Tebaldi, Piotr Wolski, Wenxia Zhang, and Vivek K. Arora
Geosci. Model Dev., 18, 4399–4416, https://doi.org/10.5194/gmd-18-4399-2025, https://doi.org/10.5194/gmd-18-4399-2025, 2025
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Climate model simulations of the response to human and natural influences together, natural climate influences alone and greenhouse gases alone are key to quantifying human influence on the climate. The last set of such coordinated simulations underpinned key findings in the last Intergovernmental Panel on Climate Change (IPCC) report. Here we propose a new set of such simulations to be used in the next generation of attribution studies and to underpin the next IPCC report.
Getachew Agmuas Adnew, Gerbrand Koren, Neha Mehendale, Sergey Gromov, Maarten Krol, and Thomas Röckmann
Atmos. Meas. Tech., 18, 2701–2719, https://doi.org/10.5194/amt-18-2701-2025, https://doi.org/10.5194/amt-18-2701-2025, 2025
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This study presents high-precision measurements of ∆′17O(CO2). Key findings include the extension of the N2O–∆′17O correlation to the upper troposphere and the identification of significant differences in the N2O–∆′17O slope in StratoClim samples. Additionally, the ∆′17O measurements are used to estimate global stratospheric production and surface removal of ∆′17O, providing an independent estimate of global vegetation CO2 exchange.
Santiago Botía, Saqr Munassar, Thomas Koch, Danilo Custodio, Luana S. Basso, Shujiro Komiya, Jost V. Lavric, David Walter, Manuel Gloor, Giordane Martins, Stijn Naus, Gerbrand Koren, Ingrid T. Luijkx, Stijn Hantson, John B. Miller, Wouter Peters, Christian Rödenbeck, and Christoph Gerbig
Atmos. Chem. Phys., 25, 6219–6255, https://doi.org/10.5194/acp-25-6219-2025, https://doi.org/10.5194/acp-25-6219-2025, 2025
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This study uses dry CO2 mole fractions from the Amazon Tall Tower Observatory together with airborne profiles to estimate net carbon exchange in tropical South America. We found that the biogeographic Amazon is a net carbon sink, while the Cerrado and Caatinga biomes are net carbon sources, resulting in an overall neutral balance. Finally, to further reduce the uncertainty in our estimates we call for an expansion of the monitoring capacity, especially in the Amazon–Andes foothills.
Cynthia H. Whaley, Tim Butler, Jose A. Adame, Rupal Ambulkar, Steve R. Arnold, Rebecca R. Buchholz, Benjamin Gaubert, Douglas S. Hamilton, Min Huang, Hayley Hung, Johannes W. Kaiser, Jacek W. Kaminski, Christoph Knote, Gerbrand Koren, Jean-Luc Kouassi, Meiyun Lin, Tianjia Liu, Jianmin Ma, Kasemsan Manomaiphiboon, Elisa Bergas Masso, Jessica L. McCarty, Mariano Mertens, Mark Parrington, Helene Peiro, Pallavi Saxena, Saurabh Sonwani, Vanisa Surapipith, Damaris Y. T. Tan, Wenfu Tang, Veerachai Tanpipat, Kostas Tsigaridis, Christine Wiedinmyer, Oliver Wild, Yuanyu Xie, and Paquita Zuidema
Geosci. Model Dev., 18, 3265–3309, https://doi.org/10.5194/gmd-18-3265-2025, https://doi.org/10.5194/gmd-18-3265-2025, 2025
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The multi-model experiment design of the HTAP3 Fires project takes a multi-pollutant approach to improving our understanding of transboundary transport of wildland fire and agricultural burning emissions and their impacts. The experiments are designed with the goal of answering science policy questions related to fires. The options for the multi-model approach, including inputs, outputs, and model setup, are discussed, and the official recommendations for the project are presented.
Michael K. Schutte, Alice Portal, Simon H. Lee, and Gabriele Messori
Weather Clim. Dynam., 6, 521–548, https://doi.org/10.5194/wcd-6-521-2025, https://doi.org/10.5194/wcd-6-521-2025, 2025
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Large-scale motions in the atmosphere, namely atmospheric waves, greatly impact the weather that we experience at the Earth's surface. Here we investigate how waves in the troposphere (the lower 10 km of the atmosphere) and the stratosphere (above the troposphere) interact to affect surface weather. We find that tropospheric waves that are reflected back down by the stratosphere change weather patterns and temperatures in North America. These changes can indirectly affect the weather in Europe.
Takashi Sekiya, Emanuele Emili, Kazuyuki Miyazaki, Antje Inness, Zhen Qu, R. Bradley Pierce, Dylan Jones, Helen Worden, William Y. Y. Cheng, Vincent Huijnen, and Gerbrand Koren
Atmos. Chem. Phys., 25, 2243–2268, https://doi.org/10.5194/acp-25-2243-2025, https://doi.org/10.5194/acp-25-2243-2025, 2025
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Five global chemical reanalysis datasets were used to assess the relative impacts of assimilating satellite ozone and its precursor measurements on tropospheric ozone analyses for 2010. The multiple reanalysis system comparison allows an evaluation of the dependency of the impacts on different reanalysis systems. The results suggested the importance of satellite ozone and its precursor measurements for improving ozone analysis in the whole troposphere, with varying magnitudes among the systems.
Chaim I. Garfinkel, Zachary D. Lawrence, Amy H. Butler, Etienne Dunn-Sigouin, Irene Erner, Alexey Y. Karpechko, Gerbrand Koren, Marta Abalos, Blanca Ayarzagüena, David Barriopedro, Natalia Calvo, Alvaro de la Cámara, Andrew Charlton-Perez, Judah Cohen, Daniela I. V. Domeisen, Javier García-Serrano, Neil P. Hindley, Martin Jucker, Hera Kim, Robert W. Lee, Simon H. Lee, Marisol Osman, Froila M. Palmeiro, Inna Polichtchouk, Jian Rao, Jadwiga H. Richter, Chen Schwartz, Seok-Woo Son, Masakazu Taguchi, Nicholas L. Tyrrell, Corwin J. Wright, and Rachel W.-Y. Wu
Weather Clim. Dynam., 6, 171–195, https://doi.org/10.5194/wcd-6-171-2025, https://doi.org/10.5194/wcd-6-171-2025, 2025
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Variability in the extratropical stratosphere and troposphere is coupled, and because of the longer timescales characteristic of the stratosphere, this allows for a window of opportunity for surface prediction. This paper assesses whether models used for operational prediction capture these coupling processes accurately. We find that most processes are too weak; however downward coupling from the lower stratosphere to the near surface is too strong.
Ferran Lopez-Marti, Mireia Ginesta, Davide Faranda, Anna Rutgersson, Pascal Yiou, Lichuan Wu, and Gabriele Messori
Earth Syst. Dynam., 16, 169–187, https://doi.org/10.5194/esd-16-169-2025, https://doi.org/10.5194/esd-16-169-2025, 2025
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Explosive cyclones and atmospheric rivers are two main drivers of extreme weather in Europe. In this study, we investigate their joint changes in future climates over the North Atlantic. Our results show that both the concurrence of these events and the intensity of atmospheric rivers increase by the end of the century across different future scenarios. Furthermore, explosive cyclones associated with atmospheric rivers last longer and are deeper than those without atmospheric rivers.
Thomas J. Ballinger, Kent Moore, Qinghua Ding, Amy H. Butler, James E. Overland, Richard L. Thoman, Ian Baxter, Zhe Li, and Edward Hanna
Weather Clim. Dynam., 5, 1473–1488, https://doi.org/10.5194/wcd-5-1473-2024, https://doi.org/10.5194/wcd-5-1473-2024, 2024
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This study chronicles the meteorological conditions that led to the anomalous, tandem March 2023 ice melt event in the Labrador and Bering seas. A sudden stratospheric warming event initiated the development of an anticyclonic circulation pattern over the Greenland–Labrador region, while the La Niña background state supported ridging conditions over Alaska, both of which aided northward transport of warm, moist air and drove the concurrent sea ice melt extremes.
Benjamin M. Sanderson, Ben B. B. Booth, John Dunne, Veronika Eyring, Rosie A. Fisher, Pierre Friedlingstein, Matthew J. Gidden, Tomohiro Hajima, Chris D. Jones, Colin G. Jones, Andrew King, Charles D. Koven, David M. Lawrence, Jason Lowe, Nadine Mengis, Glen P. Peters, Joeri Rogelj, Chris Smith, Abigail C. Snyder, Isla R. Simpson, Abigail L. S. Swann, Claudia Tebaldi, Tatiana Ilyina, Carl-Friedrich Schleussner, Roland Séférian, Bjørn H. Samset, Detlef van Vuuren, and Sönke Zaehle
Geosci. Model Dev., 17, 8141–8172, https://doi.org/10.5194/gmd-17-8141-2024, https://doi.org/10.5194/gmd-17-8141-2024, 2024
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We discuss how, in order to provide more relevant guidance for climate policy, coordinated climate experiments should adopt a greater focus on simulations where Earth system models are provided with carbon emissions from fossil fuels together with land use change instructions, rather than past approaches that have largely focused on experiments with prescribed atmospheric carbon dioxide concentrations. We discuss how these goals might be achieved in coordinated climate modeling experiments.
Leonardo Olivetti and Gabriele Messori
Geosci. Model Dev., 17, 7915–7962, https://doi.org/10.5194/gmd-17-7915-2024, https://doi.org/10.5194/gmd-17-7915-2024, 2024
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Data-driven models are becoming a viable alternative to physics-based models for weather forecasting up to 15 d into the future. However, it is unclear whether they are as reliable as physics-based models when forecasting weather extremes. We evaluate their performance in forecasting near-surface cold, hot, and windy extremes globally. We find that data-driven models can compete with physics-based models and that the choice of the best model mainly depends on the region and type of extreme.
Philip Rupp, Jonas Spaeth, Hilla Afargan-Gerstman, Dominik Büeler, Michael Sprenger, and Thomas Birner
Weather Clim. Dynam., 5, 1287–1298, https://doi.org/10.5194/wcd-5-1287-2024, https://doi.org/10.5194/wcd-5-1287-2024, 2024
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We quantify the occurrence of strong synoptic storms as contributing about 20 % to the uncertainty of subseasonal geopotential height forecasts over northern Europe. We further show that North Atlantic storms are less frequent, weaker and shifted southward following sudden stratospheric warming events, leading to a reduction in northern European forecast uncertainty.
Pharahilda M. Steur, Hubertus A. Scheeren, Gerbrand Koren, Getachew A. Adnew, Wouter Peters, and Harro A. J. Meijer
Atmos. Chem. Phys., 24, 11005–11027, https://doi.org/10.5194/acp-24-11005-2024, https://doi.org/10.5194/acp-24-11005-2024, 2024
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We present records of the triple oxygen isotope signature (Δ(17O)) of atmospheric CO2 obtained with laser absorption spectroscopy from two mid-latitude stations. Significant interannual variability is observed in both records. A model sensitivity study suggests that stratosphere–troposphere exchange, which carries high-Δ(17O) CO2 from the stratosphere into the troposphere, causes most of the variability. This makes Δ(17O) a potential tracer for stratospheric intrusions into the troposphere.
Gabriele Messori, Antonio Segalini, and Alexandre M. Ramos
Earth Syst. Dynam., 15, 1207–1225, https://doi.org/10.5194/esd-15-1207-2024, https://doi.org/10.5194/esd-15-1207-2024, 2024
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Simultaneous heatwaves or cold spells in remote geographical regions have potentially far-reaching impacts on society and the environment. Despite this, we have little knowledge of when and where these extreme events have occurred in the past decades. In this paper, we present a summary of past simultaneous heatwaves or cold spells and provide a computer program to enable other researchers to study them.
Pierluigi Renan Guaita, Riccardo Marzuoli, Leiming Zhang, Steven Turnock, Gerbrand Koren, Oliver Wild, Paola Crippa, and Giacomo Alessandro Gerosa
EGUsphere, https://doi.org/10.5194/egusphere-2024-2573, https://doi.org/10.5194/egusphere-2024-2573, 2024
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This study assesses the global impact of tropospheric ozone on wheat crops in the 21st century under various climate scenarios. The research highlights that ozone damage to wheat varies by region and depends on both ozone levels and climate. Vulnerable regions include East Asia, Northern Europe, and the Southern and Eastern edges of the Tibetan Plateau. Our results emphasize the need of policies to reduce ozone levels and mitigate climate change to protect global food security.
Marco Gaetani, Gabriele Messori, Francesco S. R. Pausata, Shivangi Tiwari, M. Carmen Alvarez Castro, and Qiong Zhang
Clim. Past, 20, 1735–1759, https://doi.org/10.5194/cp-20-1735-2024, https://doi.org/10.5194/cp-20-1735-2024, 2024
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Palaeoclimate reconstructions suggest that, around 6000 years ago, a greening of the Sahara took place, accompanied by climate changes in the Northern Hemisphere at middle to high latitudes. In this study, a climate model is used to investigate how this drastic environmental change in the Sahara impacted remote regions. Specifically, climate simulations reveal significant modifications in atmospheric circulation over the North Atlantic, affecting North American and European climates.
Antonio Segalini, Jacopo Riboldi, Volkmar Wirth, and Gabriele Messori
Weather Clim. Dynam., 5, 997–1012, https://doi.org/10.5194/wcd-5-997-2024, https://doi.org/10.5194/wcd-5-997-2024, 2024
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Planetary Rossby waves are created by topography and evolve in time. In this work, an analytical solution of this classical problem is proposed under the approximation of linear wave dynamics. The theory is able to describe reasonably well the evolution of the perturbation and compares well with full nonlinear simulations. Several relevant cases with single and double zonal jets are assessed with the theoretical framework
Davide Faranda, Gabriele Messori, Erika Coppola, Tommaso Alberti, Mathieu Vrac, Flavio Pons, Pascal Yiou, Marion Saint Lu, Andreia N. S. Hisi, Patrick Brockmann, Stavros Dafis, Gianmarco Mengaldo, and Robert Vautard
Weather Clim. Dynam., 5, 959–983, https://doi.org/10.5194/wcd-5-959-2024, https://doi.org/10.5194/wcd-5-959-2024, 2024
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We introduce ClimaMeter, a tool offering real-time insights into extreme-weather events. Our tool unveils how climate change and natural variability affect these events, affecting communities worldwide. Our research equips policymakers and the public with essential knowledge, fostering informed decisions and enhancing climate resilience. We analysed two distinct events, showcasing ClimaMeter's global relevance.
Aleksa Stanković, Gabriele Messori, Joaquim G. Pinto, and Rodrigo Caballero
Weather Clim. Dynam., 5, 821–837, https://doi.org/10.5194/wcd-5-821-2024, https://doi.org/10.5194/wcd-5-821-2024, 2024
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The article studies extreme winds near the surface over the North Atlantic Ocean. These winds are caused by storms that pass through this region. The strongest storms that have occurred in the winters from 1950–2020 are studied in detail and compared to weaker but still strong storms. The analysis shows that the storms associated with the strongest winds are preceded by another older storm that travelled through the same region and made the conditions suitable for development of extreme winds.
Juliëtte C. S. Anema, Klaas Folkert Boersma, Piet Stammes, Gerbrand Koren, William Woodgate, Philipp Köhler, Christian Frankenberg, and Jacqui Stol
Biogeosciences, 21, 2297–2311, https://doi.org/10.5194/bg-21-2297-2024, https://doi.org/10.5194/bg-21-2297-2024, 2024
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To keep the Paris agreement goals within reach, negative emissions are necessary. They can be achieved with mitigation techniques, such as reforestation, which remove CO2 from the atmosphere. While governments have pinned their hopes on them, there is not yet a good set of tools to objectively determine whether negative emissions do what they promise. Here we show how satellite measurements of plant fluorescence are useful in detecting carbon uptake due to reforestation and vegetation regrowth.
Derrick Muheki, Axel A. J. Deijns, Emanuele Bevacqua, Gabriele Messori, Jakob Zscheischler, and Wim Thiery
Earth Syst. Dynam., 15, 429–466, https://doi.org/10.5194/esd-15-429-2024, https://doi.org/10.5194/esd-15-429-2024, 2024
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Climate change affects the interaction, dependence, and joint occurrence of climate extremes. Here we investigate the joint occurrence of pairs of river floods, droughts, heatwaves, crop failures, wildfires, and tropical cyclones in East Africa under past and future climate conditions. Our results show that, across all future warming scenarios, the frequency and spatial extent of these co-occurring extremes will increase in this region, particularly in areas close to the Nile and Congo rivers.
Leonardo Olivetti and Gabriele Messori
Geosci. Model Dev., 17, 2347–2358, https://doi.org/10.5194/gmd-17-2347-2024, https://doi.org/10.5194/gmd-17-2347-2024, 2024
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In the last decades, weather forecasting up to 15 d into the future has been dominated by physics-based numerical models. Recently, deep learning models have challenged this paradigm. However, the latter models may struggle when forecasting weather extremes. In this article, we argue for deep learning models specifically designed to handle extreme events, and we propose a foundational framework to develop such models.
Marika M. Holland, Cecile Hannay, John Fasullo, Alexandra Jahn, Jennifer E. Kay, Michael Mills, Isla R. Simpson, William Wieder, Peter Lawrence, Erik Kluzek, and David Bailey
Geosci. Model Dev., 17, 1585–1602, https://doi.org/10.5194/gmd-17-1585-2024, https://doi.org/10.5194/gmd-17-1585-2024, 2024
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Climate evolves in response to changing forcings, as prescribed in simulations. Models and forcings are updated over time to reflect new understanding. This makes it difficult to attribute simulation differences to either model or forcing changes. Here we present new simulations which enable the separation of model structure and forcing influence between two widely used simulation sets. Results indicate a strong influence of aerosol emission uncertainty on historical climate.
Woon Mi Kim, Santos J. González-Rojí, Isla R. Simpson, and Daniel Kennedy
EGUsphere, https://doi.org/10.5194/egusphere-2024-252, https://doi.org/10.5194/egusphere-2024-252, 2024
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This study investigates temporal characteristics and typical circulation conditions associated with onsets and terminations of soil moisture droughts in Europe. More understanding of drought onsets and terminations can aid in improving early predictions for devastating intense droughts.
Lammert Kooistra, Katja Berger, Benjamin Brede, Lukas Valentin Graf, Helge Aasen, Jean-Louis Roujean, Miriam Machwitz, Martin Schlerf, Clement Atzberger, Egor Prikaziuk, Dessislava Ganeva, Enrico Tomelleri, Holly Croft, Pablo Reyes Muñoz, Virginia Garcia Millan, Roshanak Darvishzadeh, Gerbrand Koren, Ittai Herrmann, Offer Rozenstein, Santiago Belda, Miina Rautiainen, Stein Rune Karlsen, Cláudio Figueira Silva, Sofia Cerasoli, Jon Pierre, Emine Tanır Kayıkçı, Andrej Halabuk, Esra Tunc Gormus, Frank Fluit, Zhanzhang Cai, Marlena Kycko, Thomas Udelhoven, and Jochem Verrelst
Biogeosciences, 21, 473–511, https://doi.org/10.5194/bg-21-473-2024, https://doi.org/10.5194/bg-21-473-2024, 2024
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We reviewed optical remote sensing time series (TS) studies for monitoring vegetation productivity across ecosystems. Methods were categorized into trend analysis, land surface phenology, and assimilation into statistical or dynamic vegetation models. Due to progress in machine learning, TS processing methods will diversify, while modelling strategies will advance towards holistic processing. We propose integrating methods into a digital twin to improve the understanding of vegetation dynamics.
Michael Sigmond, James Anstey, Vivek Arora, Ruth Digby, Nathan Gillett, Viatcheslav Kharin, William Merryfield, Catherine Reader, John Scinocca, Neil Swart, John Virgin, Carsten Abraham, Jason Cole, Nicolas Lambert, Woo-Sung Lee, Yongxiao Liang, Elizaveta Malinina, Landon Rieger, Knut von Salzen, Christian Seiler, Clint Seinen, Andrew Shao, Reinel Sospedra-Alfonso, Libo Wang, and Duo Yang
Geosci. Model Dev., 16, 6553–6591, https://doi.org/10.5194/gmd-16-6553-2023, https://doi.org/10.5194/gmd-16-6553-2023, 2023
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We present a new activity which aims to organize the analysis of biases in the Canadian Earth System model (CanESM) in a systematic manner. Results of this “Analysis for Development” (A4D) activity includes a new CanESM version, CanESM5.1, which features substantial improvements regarding the simulation of dust and stratospheric temperatures, a second CanESM5.1 variant with reduced climate sensitivity, and insights into potential avenues to reduce various other model biases.
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
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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.
Kristian Strommen, Tim Woollings, Paolo Davini, Paolo Ruggieri, and Isla R. Simpson
Weather Clim. Dynam., 4, 853–874, https://doi.org/10.5194/wcd-4-853-2023, https://doi.org/10.5194/wcd-4-853-2023, 2023
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We present evidence which strongly suggests that decadal variations in the intensity of the North Atlantic winter jet stream can be predicted by current forecast models but that decadal variations in its position appear to be unpredictable. It is argued that this skill at predicting jet intensity originates from the slow, predictable variability in sea surface temperatures in the sub-polar North Atlantic.
Emma Holmberg, Gabriele Messori, Rodrigo Caballero, and Davide Faranda
Earth Syst. Dynam., 14, 737–765, https://doi.org/10.5194/esd-14-737-2023, https://doi.org/10.5194/esd-14-737-2023, 2023
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We analyse the duration of large-scale patterns of air movement in the atmosphere, referred to as persistence, and whether unusually persistent patterns favour warm-temperature extremes in Europe. We see no clear relationship between summertime heatwaves and unusually persistent patterns. This suggests that heatwaves do not necessarily require the continued flow of warm air over a region and that local effects could be important for their occurrence.
Dillon Elsbury, Amy H. Butler, John R. Albers, Melissa L. Breeden, and Andrew O'Neil Langford
Atmos. Chem. Phys., 23, 5101–5117, https://doi.org/10.5194/acp-23-5101-2023, https://doi.org/10.5194/acp-23-5101-2023, 2023
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One of the global hotspots where stratosphere-to-troposphere transport (STT) of ozone takes place is over Pacific North America (PNA). However, we do not know how or if STT over PNA will change in response to climate change. Using climate model experiments forced with
worst-casescenario Representative Concentration Pathway 8.5 climate change, we find that changes in net chemical production and transport of ozone in the lower stratosphere increase STT of ozone over PNA in the future.
Axel Kleidon, Gabriele Messori, Somnath Baidya Roy, Ira Didenkulova, and Ning Zeng
Earth Syst. Dynam., 14, 241–242, https://doi.org/10.5194/esd-14-241-2023, https://doi.org/10.5194/esd-14-241-2023, 2023
Auke M. van der Woude, Remco de Kok, Naomi Smith, Ingrid T. Luijkx, Santiago Botía, Ute Karstens, Linda M. J. Kooijmans, Gerbrand Koren, Harro A. J. Meijer, Gert-Jan Steeneveld, Ida Storm, Ingrid Super, Hubertus A. Scheeren, Alex Vermeulen, and Wouter Peters
Earth Syst. Sci. Data, 15, 579–605, https://doi.org/10.5194/essd-15-579-2023, https://doi.org/10.5194/essd-15-579-2023, 2023
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To monitor the progress towards the CO2 emission goals set out in the Paris Agreement, the European Union requires an independent validation of emitted CO2. For this validation, atmospheric measurements of CO2 can be used, together with first-guess estimates of CO2 emissions and uptake. To quickly inform end users, it is imperative that this happens in near real-time. To aid these efforts, we create estimates of European CO2 exchange at high resolution in near real time.
Felix Jäger, Philip Rupp, and Thomas Birner
Weather Clim. Dynam., 4, 49–60, https://doi.org/10.5194/wcd-4-49-2023, https://doi.org/10.5194/wcd-4-49-2023, 2023
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Mid-latitude weather is dominated by the growth, breaking and decay of baroclinic waves and associated jet shifts. A way to study this process is via idealised life-cycle simulations, which are often classified as LC1 (anticyclonic breaking, poleward shift) or LC2 (cyclonic breaking, equatorward shift), depending on details of the initial state. We show that all systems exhibit predominantly anticyclonic character and poleward net shifts if multiple wave modes are allowed to grow simultaneously.
Patrick Johannes Stoll, Rune Grand Graversen, and Gabriele Messori
Weather Clim. Dynam., 4, 1–17, https://doi.org/10.5194/wcd-4-1-2023, https://doi.org/10.5194/wcd-4-1-2023, 2023
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The atmosphere is in motion and hereby transporting warm, cold, moist, and dry air to different climate zones. In this study, we investigate how this transport of energy organises in different manners. Outside the tropics, atmospheric waves of sizes between 2000 and 8000 km, which we perceive as cyclones from the surface, transport most of the energy and moisture poleward. In the winter, large-scale weather situations become very important for transporting energy into the polar regions.
Stijn Naus, Lucas G. Domingues, Maarten Krol, Ingrid T. Luijkx, Luciana V. Gatti, John B. Miller, Emanuel Gloor, Sourish Basu, Caio Correia, Gerbrand Koren, Helen M. Worden, Johannes Flemming, Gabrielle Pétron, and Wouter Peters
Atmos. Chem. Phys., 22, 14735–14750, https://doi.org/10.5194/acp-22-14735-2022, https://doi.org/10.5194/acp-22-14735-2022, 2022
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We assimilate MOPITT CO satellite data in the TM5-4D-Var inverse modelling framework to estimate Amazon fire CO emissions for 2003–2018. We show that fire emissions have decreased over the analysis period, coincident with a decrease in deforestation rates. However, interannual variations in fire emissions are large, and they correlate strongly with soil moisture. Our results reveal an important role for robust, top-down fire CO emissions in quantifying and attributing Amazon fire intensity.
Davide Faranda, Stella Bourdin, Mireia Ginesta, Meriem Krouma, Robin Noyelle, Flavio Pons, Pascal Yiou, and Gabriele Messori
Weather Clim. Dynam., 3, 1311–1340, https://doi.org/10.5194/wcd-3-1311-2022, https://doi.org/10.5194/wcd-3-1311-2022, 2022
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We analyze the atmospheric circulation leading to impactful extreme events for the calendar year 2021 such as the Storm Filomena, Westphalia floods, Hurricane Ida and Medicane Apollo. For some of the events, we find that climate change has contributed to their occurrence or enhanced their intensity; for other events, we find that they are unprecedented. Our approach underscores the importance of considering changes in the atmospheric circulation when performing attribution studies.
Gabriele Messori, Marlene Kretschmer, Simon H. Lee, and Vivien Wendt
Weather Clim. Dynam., 3, 1215–1236, https://doi.org/10.5194/wcd-3-1215-2022, https://doi.org/10.5194/wcd-3-1215-2022, 2022
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Over 10 km above the ground, there is a region of the atmosphere called the stratosphere. While there is very little air in the stratosphere itself, its interactions with the lower parts of the atmosphere – where we live – can affect the weather. Here we study a specific example of such an interaction, whereby processes occurring at the boundary of the stratosphere can lead to a continent-wide drop in temperatures in North America during winter.
John R. Albers, Amy H. Butler, Andrew O. Langford, Dillon Elsbury, and Melissa L. Breeden
Atmos. Chem. Phys., 22, 13035–13048, https://doi.org/10.5194/acp-22-13035-2022, https://doi.org/10.5194/acp-22-13035-2022, 2022
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Ozone transported from the stratosphere contributes to background ozone concentrations in the free troposphere and to surface ozone exceedance events that affect human health. The physical processes whereby the El Niño–Southern Oscillation (ENSO) modulates North American stratosphere-to-troposphere ozone transport during spring are documented, and the usefulness of ENSO for predicting ozone events that may cause exceedances in surface air quality standards are assessed.
Valerio Lembo, Federico Fabiano, Vera Melinda Galfi, Rune Grand Graversen, Valerio Lucarini, and Gabriele Messori
Weather Clim. Dynam., 3, 1037–1062, https://doi.org/10.5194/wcd-3-1037-2022, https://doi.org/10.5194/wcd-3-1037-2022, 2022
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Eddies in mid-latitudes characterize the exchange of heat between the tropics and the poles. This exchange is largely uneven, with a few extreme events bearing most of the heat transported across latitudes in a season. It is thus important to understand what the dynamical mechanisms are behind these events. Here, we identify recurrent weather regime patterns associated with extreme transports, and we identify scales of mid-latitudinal eddies that are mostly responsible for the transport.
Stephen G. Yeager, Nan Rosenbloom, Anne A. Glanville, Xian Wu, Isla Simpson, Hui Li, Maria J. Molina, Kristen Krumhardt, Samuel Mogen, Keith Lindsay, Danica Lombardozzi, Will Wieder, Who M. Kim, Jadwiga H. Richter, Matthew Long, Gokhan Danabasoglu, David Bailey, Marika Holland, Nicole Lovenduski, Warren G. Strand, and Teagan King
Geosci. Model Dev., 15, 6451–6493, https://doi.org/10.5194/gmd-15-6451-2022, https://doi.org/10.5194/gmd-15-6451-2022, 2022
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The Earth system changes over a range of time and space scales, and some of these changes are predictable in advance. Short-term weather forecasts are most familiar, but recent work has shown that it is possible to generate useful predictions several seasons or even a decade in advance. This study focuses on predictions over intermediate timescales (up to 24 months in advance) and shows that there is promising potential to forecast a variety of changes in the natural environment.
Zachary D. Lawrence, Marta Abalos, Blanca Ayarzagüena, David Barriopedro, Amy H. Butler, Natalia Calvo, Alvaro de la Cámara, Andrew Charlton-Perez, Daniela I. V. Domeisen, Etienne Dunn-Sigouin, Javier García-Serrano, Chaim I. Garfinkel, Neil P. Hindley, Liwei Jia, Martin Jucker, Alexey Y. Karpechko, Hera Kim, Andrea L. Lang, Simon H. Lee, Pu Lin, Marisol Osman, Froila M. Palmeiro, Judith Perlwitz, Inna Polichtchouk, Jadwiga H. Richter, Chen Schwartz, Seok-Woo Son, Irene Erner, Masakazu Taguchi, Nicholas L. Tyrrell, Corwin J. Wright, and Rachel W.-Y. Wu
Weather Clim. Dynam., 3, 977–1001, https://doi.org/10.5194/wcd-3-977-2022, https://doi.org/10.5194/wcd-3-977-2022, 2022
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Forecast models that are used to predict weather often struggle to represent the Earth’s stratosphere. This may impact their ability to predict surface weather weeks in advance, on subseasonal-to-seasonal (S2S) timescales. We use data from many S2S forecast systems to characterize and compare the stratospheric biases present in such forecast models. These models have many similar stratospheric biases, but they tend to be worse in systems with low model tops located within the stratosphere.
Cameron Bertossa, Peter Hitchcock, Arthur DeGaetano, and Riwal Plougonven
EGUsphere, https://doi.org/10.5194/egusphere-2022-601, https://doi.org/10.5194/egusphere-2022-601, 2022
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This work has identified characteristic spatial and temporal scales for non-Gaussian outbreaks in forecasts, specifically, bimodality. Methodology is introduced which allows one to connect meteorological phenomena to bimodal outbreaks. Large-scale circulation interacting with local processes is uncovered as a frequent ingredient to such outbreaks. These insights not only provide a deeper understanding of the dynamical processes involved, but also have drastic implications for forecast skill.
Peter Hitchcock, Amy Butler, Andrew Charlton-Perez, Chaim I. Garfinkel, Tim Stockdale, James Anstey, Dann Mitchell, Daniela I. V. Domeisen, Tongwen Wu, Yixiong Lu, Daniele Mastrangelo, Piero Malguzzi, Hai Lin, Ryan Muncaster, Bill Merryfield, Michael Sigmond, Baoqiang Xiang, Liwei Jia, Yu-Kyung Hyun, Jiyoung Oh, Damien Specq, Isla R. Simpson, Jadwiga H. Richter, Cory Barton, Jeff Knight, Eun-Pa Lim, and Harry Hendon
Geosci. Model Dev., 15, 5073–5092, https://doi.org/10.5194/gmd-15-5073-2022, https://doi.org/10.5194/gmd-15-5073-2022, 2022
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This paper describes an experimental protocol focused on sudden stratospheric warmings to be carried out by subseasonal forecast modeling centers. These will allow for inter-model comparisons of these major disruptions to the stratospheric polar vortex and their impacts on the near-surface flow. The protocol will lead to new insights into the contribution of the stratosphere to subseasonal forecast skill and new approaches to the dynamical attribution of extreme events.
Chen Schwartz, Chaim I. Garfinkel, Priyanka Yadav, Wen Chen, and Daniela I. V. Domeisen
Weather Clim. Dynam., 3, 679–692, https://doi.org/10.5194/wcd-3-679-2022, https://doi.org/10.5194/wcd-3-679-2022, 2022
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Eleven operational forecast models that run on subseasonal timescales (up to 2 months) are examined to assess errors in their simulated large-scale stationary waves in the Northern Hemisphere winter. We found that models with a more finely resolved stratosphere generally do better in simulating the waves in both the stratosphere (10–50 km) and troposphere below. Moreover, a connection exists between errors in simulated time-mean convection in tropical regions and errors in the simulated waves.
Shlomi Ziskin Ziv, Chaim I. Garfinkel, Sean Davis, and Antara Banerjee
Atmos. Chem. Phys., 22, 7523–7538, https://doi.org/10.5194/acp-22-7523-2022, https://doi.org/10.5194/acp-22-7523-2022, 2022
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Stratospheric water vapor is important for Earth's overall greenhouse effect and for ozone chemistry; however the factors governing its variability on interannual timescales are not fully known, and previous modeling studies have indicated that models struggle to capture this interannual variability. We demonstrate that nonlinear interactions are important for determining overall water vapor concentrations and also that models have improved in their ability to capture these connections.
Shima Bahramvash Shams, Von P. Walden, James W. Hannigan, William J. Randel, Irina V. Petropavlovskikh, Amy H. Butler, and Alvaro de la Cámara
Atmos. Chem. Phys., 22, 5435–5458, https://doi.org/10.5194/acp-22-5435-2022, https://doi.org/10.5194/acp-22-5435-2022, 2022
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Large-scale atmospheric circulation has a strong influence on ozone in the Arctic, and certain anomalous dynamical events, such as sudden stratospheric warmings, cause dramatic alterations of the large-scale circulation. A reanalysis model is evaluated and then used to investigate the impact of sudden stratospheric warmings on mid-atmospheric ozone. Results show that the position of the cold jet stream over the Arctic before these events influences the variability of ozone.
Assaf Hochman, Francesco Marra, Gabriele Messori, Joaquim G. Pinto, Shira Raveh-Rubin, Yizhak Yosef, and Georgios Zittis
Earth Syst. Dynam., 13, 749–777, https://doi.org/10.5194/esd-13-749-2022, https://doi.org/10.5194/esd-13-749-2022, 2022
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Gaining a complete understanding of extreme weather, from its physical drivers to its impacts on society, is important in supporting future risk reduction and adaptation measures. Here, we provide a review of the available scientific literature, knowledge gaps and key open questions in the study of extreme weather events over the vulnerable eastern Mediterranean region.
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
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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.
Adam A. Scaife, Mark P. Baldwin, Amy H. Butler, Andrew J. Charlton-Perez, Daniela I. V. Domeisen, Chaim I. Garfinkel, Steven C. Hardiman, Peter Haynes, Alexey Yu Karpechko, Eun-Pa Lim, Shunsuke Noguchi, Judith Perlwitz, Lorenzo Polvani, Jadwiga H. Richter, John Scinocca, Michael Sigmond, Theodore G. Shepherd, Seok-Woo Son, and David W. J. Thompson
Atmos. Chem. Phys., 22, 2601–2623, https://doi.org/10.5194/acp-22-2601-2022, https://doi.org/10.5194/acp-22-2601-2022, 2022
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Great progress has been made in computer modelling and simulation of the whole climate system, including the stratosphere. Since the late 20th century we also gained a much clearer understanding of how the stratosphere interacts with the lower atmosphere. The latest generation of numerical prediction systems now explicitly represents the stratosphere and its interaction with surface climate, and here we review its role in long-range predictions and projections from weeks to decades ahead.
Nicholas A. Davis, Patrick Callaghan, Isla R. Simpson, and Simone Tilmes
Atmos. Chem. Phys., 22, 197–214, https://doi.org/10.5194/acp-22-197-2022, https://doi.org/10.5194/acp-22-197-2022, 2022
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Specified dynamics schemes attempt to constrain the atmospheric circulation in a climate model to isolate the role of transport in chemical variability, evaluate model physics, and interpret field campaign observations. We show that the specified dynamics scheme in CESM2 erroneously suppresses convection and induces circulation errors that project onto errors in tracers, even using the most optimal settings. Development of a more sophisticated scheme is necessary for future progress.
William J. Randel, Fei Wu, Alison Ming, and Peter Hitchcock
Atmos. Chem. Phys., 21, 18531–18542, https://doi.org/10.5194/acp-21-18531-2021, https://doi.org/10.5194/acp-21-18531-2021, 2021
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Balloon and satellite observations show strong coupling between large-scale ozone and temperature fields in the tropical lower stratosphere, spanning timescales of days to years. We present a simple interpretation of this behavior based on an idealized model of transport by the tropical stratospheric circulation, and good quantitative agreement with observations demonstrates that this is a useful simplification. The results provide simple understanding of observed atmospheric behavior.
Corwin J. Wright, Richard J. Hall, Timothy P. Banyard, Neil P. Hindley, Isabell Krisch, Daniel M. Mitchell, and William J. M. Seviour
Weather Clim. Dynam., 2, 1283–1301, https://doi.org/10.5194/wcd-2-1283-2021, https://doi.org/10.5194/wcd-2-1283-2021, 2021
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Major sudden stratospheric warmings (SSWs) are some of the most dramatic events in the atmosphere and are believed to help cause extreme winter weather events such as the 2018 Beast from the East in Europe and North America. Here, we use unique data from the European Space Agency's new Aeolus satellite to make the first-ever measurements at a global scale of wind changes due to an SSW in the lower part of the atmosphere to help us understand how SSWs affect the atmosphere and surface weather.
Cameron Bertossa, Peter Hitchcock, Arthur DeGaetano, and Riwal Plougonven
Weather Clim. Dynam., 2, 1209–1224, https://doi.org/10.5194/wcd-2-1209-2021, https://doi.org/10.5194/wcd-2-1209-2021, 2021
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While the assumption of Gaussianity leads to many simplifications, ensemble forecasts often exhibit non-Gaussian distributions. This work has systematically identified the presence of a specific case of
non-Gaussianity, bimodality. It has been found that bimodality occurs in a large portion of global 2 m temperature forecasts. This has drastic implications on forecast skill as the minimum probability in a bimodal distribution often lies at the maximum probability of a Gaussian distribution.
Keith B. Rodgers, Sun-Seon Lee, Nan Rosenbloom, Axel Timmermann, Gokhan Danabasoglu, Clara Deser, Jim Edwards, Ji-Eun Kim, Isla R. Simpson, Karl Stein, Malte F. Stuecker, Ryohei Yamaguchi, Tamás Bódai, Eui-Seok Chung, Lei Huang, Who M. Kim, Jean-François Lamarque, Danica L. Lombardozzi, William R. Wieder, and Stephen G. Yeager
Earth Syst. Dynam., 12, 1393–1411, https://doi.org/10.5194/esd-12-1393-2021, https://doi.org/10.5194/esd-12-1393-2021, 2021
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A large ensemble of simulations with 100 members has been conducted with the state-of-the-art CESM2 Earth system model, using historical and SSP3-7.0 forcing. Our main finding is that there are significant changes in the variance of the Earth system in response to anthropogenic forcing, with these changes spanning a broad range of variables important to impacts for human populations and ecosystems.
Thomas Luke Smallman, David Thomas Milodowski, Eráclito Sousa Neto, Gerbrand Koren, Jean Ometto, and Mathew Williams
Earth Syst. Dynam., 12, 1191–1237, https://doi.org/10.5194/esd-12-1191-2021, https://doi.org/10.5194/esd-12-1191-2021, 2021
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Our study provides a novel assessment of model parameter, structure and climate change scenario uncertainty contribution to future predictions of the Brazilian terrestrial carbon stocks to 2100. We calibrated (2001–2017) five models of the terrestrial C cycle of varied structure. The calibrated models were then projected to 2100 under multiple climate change scenarios. Parameter uncertainty dominates overall uncertainty, being ~ 40 times that of either model structure or climate change scenario.
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Editorial statement
Quantifying the contribution of stratospheric processes to extreme weather events is a challenge. This study breaks new ground in the quantitative attribution of weather extremes to dynamical processes in the stratosphere. It applies two complementary statistical indicators (relative risk and quantile shift) to a coordinated set of experiments with several models to study the role of the stratosphere in three detailed case studies. The paper has the potential to be an authoritative study in this area due to its combination of rigor, depth and range of impacts.
Quantifying the contribution of stratospheric processes to extreme weather events is a...
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.
Variability of the stratospheric polar vortex is thought to play a role in driving weather...
