Articles | Volume 5, issue 1
https://doi.org/10.5194/wcd-5-231-2024
© Author(s) 2024. 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-5-231-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
19 Feb 2024
Research article |
| 19 Feb 2024
| 19 Feb 2024
Stratospheric influence on the winter North Atlantic storm track in subseasonal reforecasts
Hilla Afargan-Gerstman
CORRESPONDING AUTHOR
Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
Dominik Büeler
Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
C. Ole Wulff
NORCE Norwegian Research Centre, Bjerknes Centre, Bergen, Norway
Michael Sprenger
Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
Daniela I. V. Domeisen
Department of Geosciences and Environment, Université de Lausanne, Lausanne, Switzerland
Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
Related authors
Blanca Ayarzagüena, Amy H. Butler, Peter Hitchcock, Chaim I. Garfinkel, Zac D. Lawrence, Wuhan Ning, Philip Rupp, Zheng Wu, Hilla Afargan-Gerstman, Natalia Calvo, Álvaro de la Cámara, Martin Jucker, Gerbrand Koren, Daniel De Maeseneire, Gloria L. Manney, Marisol Osman, Masakazu Taguchi, Cory Barton, Dong-Chang 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
EGUsphere, https://doi.org/10.5194/egusphere-2025-3611, https://doi.org/10.5194/egusphere-2025-3611, 2025
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
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.
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
Short summary
Short summary
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.
Luca G. Severino, Chahan M. Kropf, Hilla Afargan-Gerstman, Christopher Fairless, Andries Jan de Vries, Daniela I. V. Domeisen, and David N. Bresch
Nat. Hazards Earth Syst. Sci., 24, 1555–1578, https://doi.org/10.5194/nhess-24-1555-2024, https://doi.org/10.5194/nhess-24-1555-2024, 2024
Short summary
Short summary
We combine climate projections from 30 climate models with a climate risk model to project winter windstorm damages in Europe under climate change. We study the uncertainty and sensitivity factors related to the modelling of hazard, exposure and vulnerability. We emphasize high uncertainties in the damage projections, with climate models primarily driving the uncertainty. We find climate change reshapes future European windstorm risk by altering damage locations and intensity.
Hilla Afargan-Gerstman, Iuliia Polkova, Lukas Papritz, Paolo Ruggieri, Martin P. King, Panos J. Athanasiadis, Johanna Baehr, and Daniela I. V. Domeisen
Weather Clim. Dynam., 1, 541–553, https://doi.org/10.5194/wcd-1-541-2020, https://doi.org/10.5194/wcd-1-541-2020, 2020
Short summary
Short summary
We investigate the stratospheric influence on marine cold air outbreaks (MCAOs) in the North Atlantic using ERA-Interim reanalysis data. MCAOs are associated with severe Arctic weather, such as polar lows and strong surface winds. Sudden stratospheric events are found to be associated with more frequent MCAOs in the Barents and the Norwegian seas, affected by the anomalous circulation over Greenland and Scandinavia. Identification of MCAO precursors is crucial for improved long-range prediction.
Killian P. Brennan, Iris Thurnherr, Michael Sprenger, and Heini Wernli
Nat. Hazards Earth Syst. Sci., 25, 3693–3712, https://doi.org/10.5194/nhess-25-3693-2025, https://doi.org/10.5194/nhess-25-3693-2025, 2025
Short summary
Short summary
Hailstorms can cause severe damage to homes, crops, and infrastructure. Using high-resolution climate simulations, we tracked thousands of hailstorms across Europe to study future changes. Large hail will become more frequent, hail-covered areas will expand, and instances of extreme hail combined with heavy rain will double. These shifts could increase risks for communities and businesses, highlighting the need for better preparedness and adaptation.
Luise J. Fischer, David N. Bresch, Dominik Büeler, Christian M. Grams, Robin Noyelle, Matthias Röthlisberger, and Heini Wernli
Weather Clim. Dynam., 6, 1027–1043, https://doi.org/10.5194/wcd-6-1027-2025, https://doi.org/10.5194/wcd-6-1027-2025, 2025
Short summary
Short summary
Atmospheric flows over the North Atlantic can be meaningfully classified into weather regimes, and climate simulations suggest that the regime frequencies might change in the future. We provide a quantitative framework that helps assess whether these regime frequency changes are relevant to understanding climate change signals in precipitation. At least in our example application, in most regions, regime frequency changes explain little of the projected precipitation changes.
Wolfgang Wicker, Emmanuele Russo, and Daniela I. V. Domeisen
Weather Clim. Dynam., 6, 965–979, https://doi.org/10.5194/wcd-6-965-2025, https://doi.org/10.5194/wcd-6-965-2025, 2025
Short summary
Short summary
Heatwaves are becoming more frequent, but the contribution by atmospheric circulation changes is unclear. Experiments with an idealized model that simulates atmospheric dynamcis, but excludes clouds, radiation, and moisture, show how a poleward storm track shift increases the eastward phase speed of Rossby waves and reduces mid-latitude heatwave frequency. A comparison with real data for the Southern Hemisphere is attempted.
Annie Y.-Y. Chang, Shaun Harrigan, Maria-Helena Ramos, Massimiliano Zappa, Christian M. Grams, Daniela I. V. Domeisen, and Konrad Bogner
EGUsphere, https://doi.org/10.5194/egusphere-2025-3411, https://doi.org/10.5194/egusphere-2025-3411, 2025
This preprint is open for discussion and under review for Hydrology and Earth System Sciences (HESS).
Short summary
Short summary
This study presents a machine learning-aided hybrid forecasting framework to improve early warnings of low flows in the European Alps. It combines weather regime information, streamflow observations, and model simulations (EFAS). Even using only weather regime data improves predictions over climatology, while integrating different data sources yields the best result, emphasizing the value of integrating diverse data sources.
Katharina Hartmuth, Dominik Büeler, and Heini Wernli
EGUsphere, https://doi.org/10.5194/egusphere-2025-4111, https://doi.org/10.5194/egusphere-2025-4111, 2025
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
Short summary
Short summary
This study presents three case studies of applying a newly developed method to quantify the uncertainty of the operational ECMWF ensemble in forecasting precipitation and wind extremes associated with Mediterranean cyclones. We find that the cyclones as well as their associated extremes are predicted well for lead times ≤48 h; however, for longer lead times there is large case-to-case variability in the ensemble performance.
Blanca Ayarzagüena, Amy H. Butler, Peter Hitchcock, Chaim I. Garfinkel, Zac D. Lawrence, Wuhan Ning, Philip Rupp, Zheng Wu, Hilla Afargan-Gerstman, Natalia Calvo, Álvaro de la Cámara, Martin Jucker, Gerbrand Koren, Daniel De Maeseneire, Gloria L. Manney, Marisol Osman, Masakazu Taguchi, Cory Barton, Dong-Chang 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
EGUsphere, https://doi.org/10.5194/egusphere-2025-3611, https://doi.org/10.5194/egusphere-2025-3611, 2025
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
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.
Jacopo Riboldi, Robin Noyelle, Ellina Agayar, Hanin Binder, Marc Federer, Katharina Hartmuth, Michael Sprenger, Iris Thurnherr, and Selvakumar Vishnupriya
EGUsphere, https://doi.org/10.5194/egusphere-2025-3599, https://doi.org/10.5194/egusphere-2025-3599, 2025
This preprint is open for discussion and under review for Weather and Climate Dynamics (WCD).
Short summary
Short summary
Storm Boris hit central Europe in September 2024 with extreme precipitation and impacts: this work introduces a methodology to strengthen our comprehension of how global warming affects similar events, based on the incorporation of event-specific meteorological information. Furthermore, it contextualizes how the answer to the question "How will Boris-like storms change in a warmer climate?" depends on explicit and implicit methodological choices, with the aim to inform future research.
Lou Brett, Christopher J. White, Daniela I. V. Domeisen, Bart van den Hurk, Philip Ward, and Jakob Zscheischler
Nat. Hazards Earth Syst. Sci., 25, 2591–2611, https://doi.org/10.5194/nhess-25-2591-2025, https://doi.org/10.5194/nhess-25-2591-2025, 2025
Short summary
Short summary
Compound events, where multiple weather or climate hazards occur together, pose significant risks to both society and the environment. These events, like simultaneous wind and rain, can have more severe impacts than single hazards. Our review of compound event research from 2012–2022 reveals a rise in studies, especially on events that occur concurrently, hot and dry events, and compounding flooding. The review also highlights opportunities for research in the coming years.
Bastien François, Khalil Teber, Lou Brett, Richard Leeding, Luis Gimeno-Sotelo, Daniela I. V. Domeisen, Laura Suarez-Gutierrez, and Emanuele Bevacqua
Earth Syst. Dynam., 16, 1029–1051, https://doi.org/10.5194/esd-16-1029-2025, https://doi.org/10.5194/esd-16-1029-2025, 2025
Short summary
Short summary
Spatially compounding wind and precipitation (CWP) extremes can lead to severe impacts on society. We find that concurrent climate variability modes favor the occurrence of such wintertime spatially compounding events in the Northern Hemisphere and can even amplify the number of regions and population exposed. Our analysis highlights the importance of considering the interplay between variability modes to improve risk management of such spatially compounding events.
Huw Davies and Michael Sprenger
EGUsphere, https://doi.org/10.5194/egusphere-2025-3017, https://doi.org/10.5194/egusphere-2025-3017, 2025
Short summary
Short summary
The Stratospheric Polar Vortex (SPV) with its accompanying strong circumpolar jet is a dominant feature of the wintertime stratosphere. Evidence is presented that the SPV’s periphery often possesses distinctive sub-planetary scale features. The scale and dynamics of the features are linked to the break-up of an annular band of strong vorticity at the SPV’s periphery, and the latter’s aggregation into one or two vortices due to forcing from below bears comparison to Sudden Stratospheric Warming.
Killian P. Brennan, Michael Sprenger, André Walser, Marco Arpagaus, and Heini Wernli
Weather Clim. Dynam., 6, 645–668, https://doi.org/10.5194/wcd-6-645-2025, https://doi.org/10.5194/wcd-6-645-2025, 2025
Short summary
Short summary
We studied severe hailstorms that occurred in Switzerland on 28 June 2021 using a weather prediction model to understand how they evolved. We found that the storms moved toward areas with more storm energy. Hailfall was quickly followed by heavy rain. Just before the storms died out, the air feeding them stopped coming from near the ground. We also observed a delay between different types of precipitation forming in the incoming air.
Monika Feldmann, Daniela I. V. Domeisen, and Olivia Martius
EGUsphere, https://doi.org/10.5194/egusphere-2025-2296, https://doi.org/10.5194/egusphere-2025-2296, 2025
Short summary
Short summary
Severe thunderstorm outbreaks are a source of major damage across Europe. Using historical data, we analysed the large-scale weather patterns that lead to these outbreaks in eight different regions. Three types of regions emerge: those limited by temperature, limited by moisture and overall favourable for thunderstorms; consistent with their associated weather patterns and the general climate. These findings help explain regional differences and provide a basis for future forecast improvements.
Ming Hon Franco Lee and Michael Sprenger
EGUsphere, https://doi.org/10.5194/egusphere-2025-1949, https://doi.org/10.5194/egusphere-2025-1949, 2025
Short summary
Short summary
Turbulence can occur in clear-air conditions at cruising altitude. From around 5000 clear-air turbulence events identified using aircraft measurements, nonlinear breaking of large-scale waves and rapidly ascending airstreams associated with cyclones are found concurrent with 40 % and 30 % of them respectively. The results further show that these weather systems may trigger turbulence by generating highly deformed flow or flow instability, improving our understanding of clear-air turbulence.
Selvakumar Vishnupriya, Michael Sprenger, Hanna Joos, and Heini Wernli
EGUsphere, https://doi.org/10.5194/egusphere-2025-1731, https://doi.org/10.5194/egusphere-2025-1731, 2025
Short summary
Short summary
Extratropical cyclones feature rapidly ascending airstreams known as warm conveyor belts, which influence upper-level flow dynamics. This study classifies interactions of warm conveyor belts with the jet stream into four types: no interactions, ridges, blocks, and tropospheric cutoffs. We use reanalysis data to show that the interaction type depends more on the structure of the ambient flow than on the WCB properties, which improves the understanding of extratropical flow variability.
Nicolai Krieger, Heini Wernli, Michael Sprenger, and Christian Kühnlein
Weather Clim. Dynam., 6, 447–469, https://doi.org/10.5194/wcd-6-447-2025, https://doi.org/10.5194/wcd-6-447-2025, 2025
Short summary
Short summary
This study investigates the Laseyer, a local windstorm in a narrow Swiss valley characterized by strong southeasterly winds during northwesterly ambient flow. Using large-eddy simulations (LESs) with 30 m grid spacing, this is the first study to reveal that the extreme gusts in the valley are caused by an amplifying interplay of two recirculation regions. Modifying terrain and ambient wind conditions affects the windstorm's intensity and highlights the importance of topographic details in LES.
Alexander Pietak, Langwen Huang, Luigi Fusco, Michael Sprenger, Sebastian Schemm, and Torsten Hoefler
EGUsphere, https://doi.org/10.5194/egusphere-2025-793, https://doi.org/10.5194/egusphere-2025-793, 2025
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
Short summary
Short summary
As meteorological models grow in complexity, the volume of output data increases, making compression increasingly desirable. However, no specialized methods currently exist for compressing data in the Lagrangian frame. To address this gap, we developed psit, a pipeline for the lossy compression of Lagrangian flow data. In most cases, psit achieves performance that is equivalent or superior to non specialized alternatives, with compression errors behaving similar to measurement inaccuracies.
Marc Federer, Lukas Papritz, Michael Sprenger, and Christian M. Grams
Weather Clim. Dynam., 6, 211–230, https://doi.org/10.5194/wcd-6-211-2025, https://doi.org/10.5194/wcd-6-211-2025, 2025
Short summary
Short summary
Although extratropical cyclones in the North Atlantic are among the most impactful midlatitude weather systems, their intensification is not entirely understood. Here, we explore how individual cyclones convert available potential energy (APE) into kinetic energy and relate these conversions to the synoptic development of the cyclones. By combining potential vorticity thinking with a local APE framework, we offer a novel perspective on established concepts in dynamic meteorology.
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.
Pauline Rivoire, Sonia Dupuis, Antoine Guisan, Pascal Vittoz, and Daniela I. V. Domeisen
EGUsphere, https://doi.org/10.5194/egusphere-2024-3482, https://doi.org/10.5194/egusphere-2024-3482, 2024
Short summary
Short summary
Our study investigates the conditions in temperature, precipitation, humidity, and soil moisture leading to the browning of the European forests in summer. Using a Random Forest model and satellite measurement of vegetation greenness, we identify key conditions that predict forest damage. We conclude that hot and dry conditions in spring and summer are adverse conditions, in particular for broad-leaved trees. The hydro-meteorological conditions during the preceding year can also have an impact.
Rachel W.-Y. Wu, Gabriel Chiodo, Inna Polichtchouk, and Daniela I. V. Domeisen
Atmos. Chem. Phys., 24, 12259–12275, https://doi.org/10.5194/acp-24-12259-2024, https://doi.org/10.5194/acp-24-12259-2024, 2024
Short summary
Short summary
Strong variations in the strength of the stratospheric polar vortex can profoundly affect surface weather extremes; therefore, accurately predicting the stratosphere can improve surface weather forecasts. The research reveals how uncertainty in the stratosphere is linked to the troposphere. The findings suggest that refining models to better represent the identified sources and impact regions in the troposphere is likely to improve the prediction of the stratosphere and its surface impacts.
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
Short summary
Short summary
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.
Emmanouil Flaounas, Stavros Dafis, Silvio Davolio, Davide Faranda, Christian Ferrarin, Katharina Hartmuth, Assaf Hochman, Aristeidis Koutroulis, Samira Khodayar, Mario Marcello Miglietta, Florian Pantillon, Platon Patlakas, Michael Sprenger, and Iris Thurnherr
EGUsphere, https://doi.org/10.5194/egusphere-2024-2809, https://doi.org/10.5194/egusphere-2024-2809, 2024
Short summary
Short summary
Storm Daniel (2023) is one of the most catastrophic ones ever documented in the Mediterranean. Our results highlight the different dynamics and therefore the different predictability skill of precipitation, its extremes and impacts that have been produced in Greece and Libya, the two most affected countries. Our approach concerns a holistic analysis of the storm by articulating dynamics, weather prediction, hydrological and oceanographic implications, climate extremes and attribution theory.
Michael Schutte, Daniela I. V. Domeisen, and Jacopo Riboldi
Weather Clim. Dynam., 5, 733–752, https://doi.org/10.5194/wcd-5-733-2024, https://doi.org/10.5194/wcd-5-733-2024, 2024
Short summary
Short summary
The winter circulation in the stratosphere, a layer of the Earth’s atmosphere between 10 and 50 km height, is tightly linked to the circulation in the lower atmosphere determining our daily weather. This interconnection happens in the form of waves propagating in and between these two layers. Here, we use space–time spectral analysis to show that disruptions and enhancements of the stratospheric circulation modify the shape and propagation of waves in both layers.
Luca G. Severino, Chahan M. Kropf, Hilla Afargan-Gerstman, Christopher Fairless, Andries Jan de Vries, Daniela I. V. Domeisen, and David N. Bresch
Nat. Hazards Earth Syst. Sci., 24, 1555–1578, https://doi.org/10.5194/nhess-24-1555-2024, https://doi.org/10.5194/nhess-24-1555-2024, 2024
Short summary
Short summary
We combine climate projections from 30 climate models with a climate risk model to project winter windstorm damages in Europe under climate change. We study the uncertainty and sensitivity factors related to the modelling of hazard, exposure and vulnerability. We emphasize high uncertainties in the damage projections, with climate models primarily driving the uncertainty. We find climate change reshapes future European windstorm risk by altering damage locations and intensity.
Katharina Heitmann, Michael Sprenger, Hanin Binder, Heini Wernli, and Hanna Joos
Weather Clim. Dynam., 5, 537–557, https://doi.org/10.5194/wcd-5-537-2024, https://doi.org/10.5194/wcd-5-537-2024, 2024
Short summary
Short summary
Warm conveyor belts (WCBs) are coherently ascending air streams that occur in extratropical cyclones where they form precipitation and often affect the large-scale flow. We quantified the key characteristics and impacts of WCBs and linked them to different phases in the cyclone life cycle and to different WCB branches. A climatology of these metrics revealed that WCBs are most intense during cyclone intensification and that the cyclonic and anticyclonic WCB branches show distinct differences.
Lukas Jansing, Lukas Papritz, and Michael Sprenger
Weather Clim. Dynam., 5, 463–489, https://doi.org/10.5194/wcd-5-463-2024, https://doi.org/10.5194/wcd-5-463-2024, 2024
Short summary
Short summary
Using an innovative approach, the descent of foehn is diagnosed from a Lagrangian perspective based on 15 kilometer-scale simulations combined with online trajectories. The descent is confined to distinct hotspots in the immediate lee of local mountain peaks and chains. Two detailed case studies reveal a varying wave regime to be associated with the descent. Furthermore, additional controlling factors, such as the diurnal cycle, likewise influence the descent activity.
Romain Pilon and Daniela I. V. Domeisen
Geosci. Model Dev., 17, 2247–2264, https://doi.org/10.5194/gmd-17-2247-2024, https://doi.org/10.5194/gmd-17-2247-2024, 2024
Short summary
Short summary
This paper introduces a new method for detecting atmospheric cloud bands to identify long convective cloud bands that extend from the tropics to the midlatitudes. The algorithm allows for easy use and enables researchers to study the life cycle and climatology of cloud bands and associated rainfall. This method provides insights into the large-scale processes involved in cloud band formation and their connections between different regions, as well as differences across ocean basins.
Yonatan Givon, Or Hess, Emmanouil Flaounas, Jennifer Louise Catto, Michael Sprenger, and Shira Raveh-Rubin
Weather Clim. Dynam., 5, 133–162, https://doi.org/10.5194/wcd-5-133-2024, https://doi.org/10.5194/wcd-5-133-2024, 2024
Short summary
Short summary
A novel classification of Mediterranean cyclones is presented, enabling a separation between storms driven by different atmospheric processes. The surface impact of each cyclone class differs greatly by precipitation, winds, and temperatures, providing an invaluable tool to study the climatology of different types of Mediterranean storms and enhancing the understanding of their predictability, on both weather and climate scales.
Maria Pyrina, Wolfgang Wicker, Andries Jan de Vries, Georgios Fragkoulidis, and Daniela I. V. Domeisen
EGUsphere, https://doi.org/10.5194/egusphere-2023-3088, https://doi.org/10.5194/egusphere-2023-3088, 2024
Preprint withdrawn
Short summary
Short summary
We investigate the atmospheric dynamics behind heatwaves, specifically of those occurring simultaneously across regions, known as concurrent heatwaves. We find that heatwaves are strongly modulated by Rossby wave packets, being Rossby waves whose amplitude has a local maximum and decays at larger distances. High amplitude Rossby wave packets increase the occurrence probabilities of concurrent and non-concurrent heatwaves by a factor of 15 and 18, respectively, over several regions globally.
Stefania Gilardoni, Dominic Heslin-Rees, Mauro Mazzola, Vito Vitale, Michael Sprenger, and Radovan Krejci
Atmos. Chem. Phys., 23, 15589–15607, https://doi.org/10.5194/acp-23-15589-2023, https://doi.org/10.5194/acp-23-15589-2023, 2023
Short summary
Short summary
Models still fail in reproducing black carbon (BC) temporal variability in the Arctic. Analysis of equivalent BC concentrations in the European Arctic shows that BC seasonal variability is modulated by the efficiency of removal by precipitation during transport towards high latitudes. Short-term variability is controlled by synoptic-scale circulation patterns. The advection of warm air from lower latitudes is an effective pollution transport pathway during summer.
David Martin Straus, Daniela I. V. Domeisen, Sarah-Jane Lock, Franco Molteni, and Priyanka Yadav
Weather Clim. Dynam., 4, 1001–1018, https://doi.org/10.5194/wcd-4-1001-2023, https://doi.org/10.5194/wcd-4-1001-2023, 2023
Short summary
Short summary
The global response to the Madden–Julian oscillation (MJO) is potentially predictable. Yet the diabatic heating is uncertain even within a particular episode of the MJO. Experiments with a global model probe the limitations imposed by this uncertainty. The large-scale tropical heating is predictable for 25 to 45 d, yet the associated Rossby wave source that links the heating to the midlatitude circulation is predictable for 15 to 20 d. This limitation has not been recognized in prior work.
Thomas Trickl, Martin Adelwart, Dina Khordakova, Ludwig Ries, Christian Rolf, Michael Sprenger, Wolfgang Steinbrecht, and Hannes Vogelmann
Atmos. Meas. Tech., 16, 5145–5165, https://doi.org/10.5194/amt-16-5145-2023, https://doi.org/10.5194/amt-16-5145-2023, 2023
Short summary
Short summary
Tropospheric ozone have been measured for more than a century. Highly quantitative ozone measurements have been made at monitoring stations. However, deficits have been reported for vertical sounding systems. Here, we report a thorough intercomparison effort between a differential-absorption lidar system and two types of balloon-borne ozone sondes, also using ozone sensors at nearby mountain sites as references. The sondes agree very well with the lidar after offset corrections.
Gabriel Chiodo, Marina Friedel, Svenja Seeber, Daniela Domeisen, Andrea Stenke, Timofei Sukhodolov, and Franziska Zilker
Atmos. Chem. Phys., 23, 10451–10472, https://doi.org/10.5194/acp-23-10451-2023, https://doi.org/10.5194/acp-23-10451-2023, 2023
Short summary
Short summary
Stratospheric ozone protects the biosphere from harmful UV radiation. Anthropogenic activity has led to a reduction in the ozone layer in the recent past, but thanks to the implementation of the Montreal Protocol, the ozone layer is projected to recover. In this study, we show that projected future changes in Arctic ozone abundances during springtime will influence stratospheric climate and thereby actively modulate large-scale circulation changes in the Northern Hemisphere.
Melanie Lauer, Annette Rinke, Irina Gorodetskaya, Michael Sprenger, Mario Mech, and Susanne Crewell
Atmos. Chem. Phys., 23, 8705–8726, https://doi.org/10.5194/acp-23-8705-2023, https://doi.org/10.5194/acp-23-8705-2023, 2023
Short summary
Short summary
We present a new method to analyse the influence of atmospheric rivers (ARs), cyclones, and fronts on the precipitation in the Arctic, based on two campaigns: ACLOUD (early summer 2017) and AFLUX (early spring 2019). There are differences between both campaign periods: in early summer, the precipitation is mostly related to ARs and fronts, especially when they are co-located, while in early spring, cyclones isolated from ARs and fronts contributed most to the precipitation.
Emmanouil Flaounas, Leonardo Aragão, Lisa Bernini, Stavros Dafis, Benjamin Doiteau, Helena Flocas, Suzanne L. Gray, Alexia Karwat, John Kouroutzoglou, Piero Lionello, Mario Marcello Miglietta, Florian Pantillon, Claudia Pasquero, Platon Patlakas, María Ángeles Picornell, Federico Porcù, Matthew D. K. Priestley, Marco Reale, Malcolm J. Roberts, Hadas Saaroni, Dor Sandler, Enrico Scoccimarro, Michael Sprenger, and Baruch Ziv
Weather Clim. Dynam., 4, 639–661, https://doi.org/10.5194/wcd-4-639-2023, https://doi.org/10.5194/wcd-4-639-2023, 2023
Short summary
Short summary
Cyclone detection and tracking methods (CDTMs) have different approaches in defining and tracking cyclone centers. This leads to disagreements on extratropical cyclone climatologies. We present a new approach that combines tracks from individual CDTMs to produce new composite tracks. These new tracks are shown to correspond to physically meaningful systems with distinctive life stages.
Jake W. Casselman, Joke F. Lübbecke, Tobias Bayr, Wenjuan Huo, Sebastian Wahl, and Daniela I. V. Domeisen
Weather Clim. Dynam., 4, 471–487, https://doi.org/10.5194/wcd-4-471-2023, https://doi.org/10.5194/wcd-4-471-2023, 2023
Short summary
Short summary
El Niño–Southern Oscillation (ENSO) has remote effects on the tropical North Atlantic (TNA), but the connections' nonlinearity (strength of response to an increasing ENSO signal) is not always well represented in models. Using the Community Earth System Model version 1 – Whole Atmosphere Community Climate Mode (CESM-WACCM) and the Flexible Ocean and Climate Infrastructure version 1, we find that the TNA responds linearly to extreme El Niño but nonlinearly to extreme La Niña for CESM-WACCM.
Raphaël de Fondeville, Zheng Wu, Enikő Székely, Guillaume Obozinski, and Daniela I. V. Domeisen
Weather Clim. Dynam., 4, 287–307, https://doi.org/10.5194/wcd-4-287-2023, https://doi.org/10.5194/wcd-4-287-2023, 2023
Short summary
Short summary
We propose a fully data-driven, interpretable, and computationally scalable framework to characterize sudden stratospheric warmings (SSWs), extract statistically significant precursors, and produce machine learning (ML) forecasts. By successfully leveraging the long-lasting impact of SSWs, the ML predictions outperform sub-seasonal numerical forecasts for lead times beyond 25 d. Post-processing numerical predictions using their ML counterparts yields a performance increase of up to 20 %.
Hanna Joos, Michael Sprenger, Hanin Binder, Urs Beyerle, and Heini Wernli
Weather Clim. Dynam., 4, 133–155, https://doi.org/10.5194/wcd-4-133-2023, https://doi.org/10.5194/wcd-4-133-2023, 2023
Short summary
Short summary
Warm conveyor belts (WCBs) are strongly ascending, cloud- and precipitation-forming airstreams in extratropical cyclones. In this study we assess their representation in a climate simulation and their changes under global warming. They become moister, become more intense, and reach higher altitudes in a future climate, implying that they potentially have an increased impact on the mid-latitude flow.
Andreas Schäfler, Michael Sprenger, Heini Wernli, Andreas Fix, and Martin Wirth
Atmos. Chem. Phys., 23, 999–1018, https://doi.org/10.5194/acp-23-999-2023, https://doi.org/10.5194/acp-23-999-2023, 2023
Short summary
Short summary
In this study, airborne lidar profile measurements of H2O and O3 across a midlatitude jet stream are combined with analyses in tracer–trace space and backward trajectories. We highlight that transport and mixing processes in the history of the observed air masses are governed by interacting tropospheric weather systems on synoptic timescales. We show that these weather systems play a key role in the high variability of the paired H2O and O3 distributions near the tropopause.
Wolfgang Wicker, Inna Polichtchouk, and Daniela I. V. Domeisen
Weather Clim. Dynam., 4, 81–93, https://doi.org/10.5194/wcd-4-81-2023, https://doi.org/10.5194/wcd-4-81-2023, 2023
Short summary
Short summary
Sudden stratospheric warmings are extreme weather events where the winter polar stratosphere warms by about 25 K. An improved representation of small-scale gravity waves in sub-seasonal prediction models can reduce forecast errors since their impact on the large-scale circulation is predictable multiple weeks ahead. After a sudden stratospheric warming, vertically propagating gravity waves break at a lower altitude than usual, which strengthens the long-lasting positive temperature anomalies.
Hanin Binder, Hanna Joos, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 4, 19–37, https://doi.org/10.5194/wcd-4-19-2023, https://doi.org/10.5194/wcd-4-19-2023, 2023
Short summary
Short summary
Warm conveyor belts (WCBs) are the main cloud- and precipitation-producing airstreams in extratropical cyclones. The latent heat release that occurs during cloud formation often contributes to the intensification of the associated cyclone. Based on the Community Earth System Model Large Ensemble coupled climate simulations, we show that WCBs and associated latent heating will become stronger in a future climate and be even more important for explosive cyclone intensification than in the present.
Michael A. Barnes, Thando Ndarana, Michael Sprenger, and Willem A. Landman
Weather Clim. Dynam., 3, 1291–1309, https://doi.org/10.5194/wcd-3-1291-2022, https://doi.org/10.5194/wcd-3-1291-2022, 2022
Short summary
Short summary
Stratospheric air can intrude into the troposphere and is associated with cyclonic development throughout the atmosphere. Through a highly idealized systematic approach, the effect that different intrusion characteristics have on surface cyclogenetic forcing is investigated. The proximity of stratospheric intrusions to the surface is shown to be the main factor in surface cyclogenetic forcing, whilst its width is an additional contributing factor.
Marina Friedel, Gabriel Chiodo, Andrea Stenke, Daniela I. V. Domeisen, and Thomas Peter
Atmos. Chem. Phys., 22, 13997–14017, https://doi.org/10.5194/acp-22-13997-2022, https://doi.org/10.5194/acp-22-13997-2022, 2022
Short summary
Short summary
In spring, winds the Arctic stratosphere change direction – an event called final stratospheric warming (FSW). Here, we examine whether the interannual variability in Arctic stratospheric ozone impacts the timing of the FSW. We find that Arctic ozone shifts the FSW to earlier and later dates in years with high and low ozone via the absorption of UV light. The modulation of the FSW by ozone has consequences for surface climate in ozone-rich years, which may result in better seasonal predictions.
Nora Bergner, Marina Friedel, Daniela I. V. Domeisen, Darryn Waugh, and Gabriel Chiodo
Atmos. Chem. Phys., 22, 13915–13934, https://doi.org/10.5194/acp-22-13915-2022, https://doi.org/10.5194/acp-22-13915-2022, 2022
Short summary
Short summary
Polar vortex extremes, particularly situations with an unusually weak cyclonic circulation in the stratosphere, can influence the surface climate in the spring–summer time in the Southern Hemisphere. Using chemistry-climate models and observations, we evaluate the robustness of the surface impacts. While models capture the general surface response, they do not show the observed climate patterns in midlatitude regions, which we trace back to biases in the models' circulations.
Lukas Jansing, Lukas Papritz, Bruno Dürr, Daniel Gerstgrasser, and Michael Sprenger
Weather Clim. Dynam., 3, 1113–1138, https://doi.org/10.5194/wcd-3-1113-2022, https://doi.org/10.5194/wcd-3-1113-2022, 2022
Short summary
Short summary
This study presents a 5-year climatology of three main foehn types and three deep-foehn subtypes. The main types differ in their large-scale and Alpine-scale weather conditions and the subtypes in terms of the amount and extent of precipitation on the Alpine south side. The different types of foehn are found to strongly affect the local meteorological conditions at Altdorf. The study concludes by setting the new classification into a historic context.
Jake W. Casselman, Bernat Jiménez-Esteve, and Daniela I. V. Domeisen
Weather Clim. Dynam., 3, 1077–1096, https://doi.org/10.5194/wcd-3-1077-2022, https://doi.org/10.5194/wcd-3-1077-2022, 2022
Short summary
Short summary
Using an atmospheric general circulation model, we analyze how the tropical North Atlantic influences the El Niño–Southern Oscillation connection towards the North Atlantic European region. We also focus on the lesser-known boreal spring and summer response following an El Niño–Southern Oscillation event. Our results show that altered tropical Atlantic sea surface temperatures may cause different responses over the Caribbean region, consequently influencing the North Atlantic European region.
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.
Rachel Wai-Ying Wu, Zheng Wu, and Daniela I.V. Domeisen
Weather Clim. Dynam., 3, 755–776, https://doi.org/10.5194/wcd-3-755-2022, https://doi.org/10.5194/wcd-3-755-2022, 2022
Short summary
Short summary
Accurate predictions of the stratospheric polar vortex can enhance surface weather predictability. Stratospheric events themselves are less predictable, with strong inter-event differences. We assess the predictability of stratospheric acceleration and deceleration events in a sub-seasonal prediction system, finding that the predictability of events is largely dependent on event magnitude, while extreme drivers of deceleration events are not fully represented in the model.
Peter Hitchcock, Amy Butler, Andrew Charlton-Perez, Chaim I. Garfinkel, Tim Stockdale, James Anstey, Dann Mitchell, Daniela I. V. Domeisen, Tongwen Wu, Yixiong Lu, Daniele Mastrangelo, Piero Malguzzi, Hai Lin, Ryan Muncaster, Bill Merryfield, Michael Sigmond, Baoqiang Xiang, Liwei Jia, Yu-Kyung Hyun, Jiyoung Oh, Damien Specq, Isla R. Simpson, Jadwiga H. Richter, Cory Barton, Jeff Knight, Eun-Pa Lim, and Harry Hendon
Geosci. Model Dev., 15, 5073–5092, https://doi.org/10.5194/gmd-15-5073-2022, https://doi.org/10.5194/gmd-15-5073-2022, 2022
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.
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
Short summary
Short summary
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.
Jan Clemens, Felix Ploeger, Paul Konopka, Raphael Portmann, Michael Sprenger, and Heini Wernli
Atmos. Chem. Phys., 22, 3841–3860, https://doi.org/10.5194/acp-22-3841-2022, https://doi.org/10.5194/acp-22-3841-2022, 2022
Short summary
Short summary
Highly polluted air flows from the surface to higher levels of the atmosphere during the Asian summer monsoon. At high levels, the air is trapped within eddies. Here, we study how air masses can leave the eddy within its cutoff, how they distribute, and how their chemical composition changes. We found evidence for transport from the eddy to higher latitudes over the North Pacific and even Alaska. During transport, trace gas concentrations within cutoffs changed gradually, showing steady mixing.
Jörg Wieder, Claudia Mignani, Mario Schär, Lucie Roth, Michael Sprenger, Jan Henneberger, Ulrike Lohmann, Cyril Brunner, and Zamin A. Kanji
Atmos. Chem. Phys., 22, 3111–3130, https://doi.org/10.5194/acp-22-3111-2022, https://doi.org/10.5194/acp-22-3111-2022, 2022
Short summary
Short summary
We investigate the variation in ice-nucleating particles (INPs) relevant for primary ice formation in mixed-phased clouds over the Alps based on simultaneous in situ observations at a mountaintop and a nearby high valley (1060 m height difference). In most cases, advection from the surrounding lower regions was responsible for changes in INP concentration, causing a diurnal cycle at the mountaintop. Our study underlines the importance of the planetary boundary layer as an INP reserve.
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.
Lukas Bösiger, Michael Sprenger, Maxi Boettcher, Hanna Joos, and Tobias Günther
Geosci. Model Dev., 15, 1079–1096, https://doi.org/10.5194/gmd-15-1079-2022, https://doi.org/10.5194/gmd-15-1079-2022, 2022
Short summary
Short summary
Jet streams are coherent air flows that interact with atmospheric structures such as warm conveyor belts (WCBs) and the tropopause. Individually, these structures have a significant impact on the weather evolution. A first step towards a deeper understanding of the meteorological processes is to extract jet stream core lines, for which we develop a novel feature extraction algorithm. Based on the line geometry, we automatically detect and visualize potential interactions between WCBs and jets.
Philippe Besson, Luise J. Fischer, Sebastian Schemm, and Michael Sprenger
Weather Clim. Dynam., 2, 991–1009, https://doi.org/10.5194/wcd-2-991-2021, https://doi.org/10.5194/wcd-2-991-2021, 2021
Short summary
Short summary
The strongest cyclone intensification is associated with a strong dry-dynamical forcing. Moreover, strong forcing and strong intensification correspond to a tendency for poleward cyclone propagation, which occurs in distinct regions in the Northern Hemisphere. There is a clear spatial pattern in the occurrence of certain forcing combinations. This implies a fundamental relationship between dry-dynamical processes and the intensification as well as the propagation of extratropical cyclones.
Zheng Wu, Bernat Jiménez-Esteve, Raphaël de Fondeville, Enikő Székely, Guillaume Obozinski, William T. Ball, and Daniela I. V. Domeisen
Weather Clim. Dynam., 2, 841–865, https://doi.org/10.5194/wcd-2-841-2021, https://doi.org/10.5194/wcd-2-841-2021, 2021
Short summary
Short summary
We use an advanced statistical approach to investigate the dynamics of the development of sudden stratospheric warming (SSW) events in the winter Northern Hemisphere. We identify distinct signals that are representative of these events and their event type at lead times beyond currently predictable lead times. The results can be viewed as a promising step towards improving the predictability of SSWs in the future by using more advanced statistical methods in operational forecasting systems.
Raphael Portmann, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 2, 507–534, https://doi.org/10.5194/wcd-2-507-2021, https://doi.org/10.5194/wcd-2-507-2021, 2021
Short summary
Short summary
We explore the three-dimensional life cycle of cyclonic structures
(so-called PV cutoffs) near the tropopause. PV cutoffs are frequent weather systems in the extratropics that lead to high-impact weather. However, many unknowns exist regarding their evolution. We present a new method to track PV cutoffs as 3D objects in reanalysis data by following air parcels along the flow. We study the climatological life cycles of PV cutoffs in detail and propose a classification into three types.
Amy H. Butler and Daniela I. V. Domeisen
Weather Clim. Dynam., 2, 453–474, https://doi.org/10.5194/wcd-2-453-2021, https://doi.org/10.5194/wcd-2-453-2021, 2021
Short summary
Short summary
We classify by wave geometry the stratospheric polar vortex during the final warming that occurs every spring in both hemispheres due to a combination of radiative and dynamical processes. We show that the shape of the vortex, as well as the timing of the seasonal transition, is linked to total column ozone prior to and surface weather following the final warming. These results have implications for prediction and our understanding of stratosphere–troposphere coupling processes in springtime.
Maxi Boettcher, Andreas Schäfler, Michael Sprenger, Harald Sodemann, Stefan Kaufmann, Christiane Voigt, Hans Schlager, Donato Summa, Paolo Di Girolamo, Daniele Nerini, Urs Germann, and Heini Wernli
Atmos. Chem. Phys., 21, 5477–5498, https://doi.org/10.5194/acp-21-5477-2021, https://doi.org/10.5194/acp-21-5477-2021, 2021
Short summary
Short summary
Warm conveyor belts (WCBs) are important airstreams in extratropical cyclones, often leading to the formation of intense precipitation. We present a case study that involves aircraft, lidar and radar observations of water and clouds in a WCB ascending from western Europe across the Alps towards the Baltic Sea during the field campaigns HyMeX and T-NAWDEX-Falcon in October 2012. A probabilistic trajectory measure and an airborne tracer experiment were used to confirm the long pathway of the WCB.
Melissa L. Breeden, Amy H. Butler, John R. Albers, Michael Sprenger, and Andrew O'Neil Langford
Atmos. Chem. Phys., 21, 2781–2794, https://doi.org/10.5194/acp-21-2781-2021, https://doi.org/10.5194/acp-21-2781-2021, 2021
Short summary
Short summary
Prior research has found a maximum in deep stratosphere-to-troposphere mass/ozone transport over the western United States in boreal spring, which can enhance surface ozone concentrations, reducing air quality. We find that the winter-to-summer evolution of the north Pacific jet increases the frequency of stratospheric intrusions that drive transport, helping explain the observed maximum. The El Niño–Southern Oscillation affects the timing of the spring jet transition and therefore transport.
Annika Oertel, Michael Sprenger, Hanna Joos, Maxi Boettcher, Heike Konow, Martin Hagen, and Heini Wernli
Weather Clim. Dynam., 2, 89–110, https://doi.org/10.5194/wcd-2-89-2021, https://doi.org/10.5194/wcd-2-89-2021, 2021
Short summary
Short summary
Convection embedded in the stratiform cloud band of strongly ascending airstreams in extratropical cyclones (so-called warm conveyor belts) can influence not only surface precipitation but also the
upper-tropospheric potential vorticity (PV) and waveguide. The comparison of intense vs. moderate embedded convection shows that its strength alone is not a reliable measure for upper-tropospheric PV modification. Instead, characteristics of the ambient flow co-determine its dynamical significance.
Emmanouil Flaounas, Matthias Röthlisberger, Maxi Boettcher, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 2, 71–88, https://doi.org/10.5194/wcd-2-71-2021, https://doi.org/10.5194/wcd-2-71-2021, 2021
Short summary
Short summary
In this study we identify the wettest seasons globally and address their meteorological characteristics. We show that in different regions the wettest seasons occur in different times of the year and result from either unusually high frequencies of wet days and/or daily extremes. These high frequencies can be largely attributed to four specific weather systems, especially cyclones. Our analysis uses a thoroughly explained, novel methodology that could also be applied to climate models.
Claudia Mignani, Jörg Wieder, Michael A. Sprenger, Zamin A. Kanji, Jan Henneberger, Christine Alewell, and Franz Conen
Atmos. Chem. Phys., 21, 657–664, https://doi.org/10.5194/acp-21-657-2021, https://doi.org/10.5194/acp-21-657-2021, 2021
Short summary
Short summary
Most precipitation above land starts with ice in clouds. It is promoted by extremely rare particles. Some ice-nucleating particles (INPs) cause cloud droplets to already freeze above −15°C, a temperature at which many clouds begin to snow. We found that the abundance of such INPs among other particles of similar size is highest in precipitating air masses and lowest when air carries desert dust. This brings us closer to understanding the interactions between land, clouds, and precipitation.
Stefan Rüdisühli, Michael Sprenger, David Leutwyler, Christoph Schär, and Heini Wernli
Weather Clim. Dynam., 1, 675–699, https://doi.org/10.5194/wcd-1-675-2020, https://doi.org/10.5194/wcd-1-675-2020, 2020
Short summary
Short summary
Most precipitation over Europe is linked to low-pressure systems, cold fronts, warm fronts, or high-pressure systems. Based on a massive computer simulation able to resolve thunderstorms, we quantify in detail how much precipitation these weather systems produced during 2000–2008. We find distinct seasonal and regional differences, such as fronts precipitating a lot in fall and winter over the North Atlantic but high-pressure systems mostly in summer over the continent by way of thunderstorms.
Raphael Portmann, Juan Jesús González-Alemán, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 1, 597–615, https://doi.org/10.5194/wcd-1-597-2020, https://doi.org/10.5194/wcd-1-597-2020, 2020
Short summary
Short summary
In September 2018 an intense Mediterranean cyclone with structural similarities to a hurricane, a so-called medicane, caused severe damage in Greece. Its development was uncertain, even just a few days in advance. The reason for this was uncertainties in the jet stream over the North Atlantic 3 d prior to cyclogenesis that propagated into the Mediterranean. They led to an uncertain position of the upper-level disturbance and, as a result, of the position and thermal structure of the cyclone.
Hanin Binder, Maxi Boettcher, Hanna Joos, Michael Sprenger, and Heini Wernli
Weather Clim. Dynam., 1, 577–595, https://doi.org/10.5194/wcd-1-577-2020, https://doi.org/10.5194/wcd-1-577-2020, 2020
Short summary
Short summary
Warm conveyor belts (WCBs) are important cloud- and
precipitation-producing airstreams in extratropical cyclones. By combining satellite observations with model data from a new reanalysis dataset, this study provides detailed observational insight into the vertical cloud structure of WCBs. We find that the reanalyses essentially capture the observed cloud pattern, but the observations reveal mesoscale structures not resolved by the temporally and spatially much coarser-resolution model data.
Hilla Afargan-Gerstman, Iuliia Polkova, Lukas Papritz, Paolo Ruggieri, Martin P. King, Panos J. Athanasiadis, Johanna Baehr, and Daniela I. V. Domeisen
Weather Clim. Dynam., 1, 541–553, https://doi.org/10.5194/wcd-1-541-2020, https://doi.org/10.5194/wcd-1-541-2020, 2020
Short summary
Short summary
We investigate the stratospheric influence on marine cold air outbreaks (MCAOs) in the North Atlantic using ERA-Interim reanalysis data. MCAOs are associated with severe Arctic weather, such as polar lows and strong surface winds. Sudden stratospheric events are found to be associated with more frequent MCAOs in the Barents and the Norwegian seas, affected by the anomalous circulation over Greenland and Scandinavia. Identification of MCAO precursors is crucial for improved long-range prediction.
Cited articles
Afargan-Gerstman, H.: Scientific processing and analysis tools for studying the stratospheric downward impact in sub-seasonal to seasonal (S2S) forecasts and ERA5 reanalysis, Zenodo [code], https://doi.org/10.5281/zenodo.10076816, 2023. a
Afargan-Gerstman, H. and Domeisen, D. I. V.: Pacific modulation of the North Atlantic storm track response to sudden stratospheric warming events, Geophys. Res. Lett., 47, e2019GL085007, https://doi.org/10.1029/2019GL085007, 2020. a, b, c
Afargan-Gerstman, H., Jiménez-Esteve, B., and Domeisen, D. I.: On the Relative Importance of Stratospheric and Tropospheric Drivers for the North Atlantic Jet Response to Sudden Stratospheric Warming Events, J. Climate, 35, 2851–2865, 2022. a
Ayarzagüena, B., Barriopedro, D., Perez, J. M. G., Abalos, M., de la Camara, A., Herrera, R. G., Calvo, N., and Ordóñez, C.: Stratospheric Connection to the Abrupt End of the 2016/2017 Iberian Drought, Geophys. Res. Lett., 45, 12639–12646, 2018. a
Baldwin, M. P. and Dunkerton, T. J.: Propagation of the Arctic Oscillation from the stratosphere to the troposphere, J. Geophys. Res.-Atmos., 104, 30937–30946, 1999. a
Befort, D. J., Wild, S., Knight, J. R., Lockwood, J. F., Thornton, H. E., Hermanson, L., Bett, P. E., Weisheimer, A., and Leckebusch, G. C.: Seasonal forecast skill for extratropical cyclones and windstorms, Q. J. Roy. Meteor. Soc., 145, 92–104, 2019. a
Besson, P., Fischer, L. J., Schemm, S., and Sprenger, M.: A global analysis of the dry-dynamic forcing during cyclone growth and propagation, Weather Clim. Dynam., 2, 991–1009, https://doi.org/10.5194/wcd-2-991-2021, 2021. a
Blackmon, M., Wallace, J., Lau, N., and Mullen, S.: An observational study of the Northern Hemisphere wintertime circulation, J. Atmos. Sci., 34, 1040–1053, 1977. a
Brönnimann, S.: Impact of El Niño–Southern Oscillation on European climate, Rev. Geophys., 45, RG3003, https://doi.org/10.1029/2006RG000199, 2007. a
Butler, A. H. and Domeisen, D. I. V.: The wave geometry of final stratospheric warming events, Weather Clim. Dynam., 2, 453–474, https://doi.org/10.5194/wcd-2-453-2021, 2021. a
Cassou, C.: Intraseasonal interaction between the Madden–Julian oscillation and the North Atlantic Oscillation, Nature, 455, 523–527, 2008. a
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, 2007. a
Charlton-Perez, A. J., Ferranti, L., and Lee, R. W.: The influence of the stratospheric state on North Atlantic weather regimes, Q. J. Roy. Meteor. Soc., 144, 1140–1151, 2018. a
Domeisen, D. I. V.: Estimating the Frequency of Sudden Stratospheric Warming Events from Surface Observations of the North Atlantic Oscillation, J. Geophys. Res.-Atmos., 124, 3180–3194, 2019. a
Domeisen, D. I. V., Butler, A. H., Fröhlich, K., Bittner, M., Müller, W. A., and Baehr, J.: Seasonal predictability over Europe arising from El Niño and stratospheric variability in the MPI-ESM seasonal prediction system, J. Climate, 28, 256–271, 2015. a
Domeisen, D. I. V., Butler, A. H., Charlton-Perez, A. J., Ayarzaguena, B., Baldwin, M. P., Dunn Sigouin, E., Furtado, J. C., Garfinkel, C. I., Hitchcock, P., Karpechko, A. Y., Kim, H., Knight, J., Lang, A. L., Lim, E.-P., Marshall, A., Roff, G., Schwartz, C., Simpson, I. R., Son, S.-W., and Taguchi, M.: The Role of the Stratosphere in Subseasonal to Seasonal Prediction: 2. Predictability Arising From Stratosphere-Troposphere Coupling, J. Geophys. Res.-Atmos., 125, e2019JD030923, https://doi.org/10.1029/2019JD030923, 2020. a, b
Domeisen, D. I. V., Grams, C. M., and Papritz, L.: The role of North Atlantic–European weather regimes in the surface impact of sudden stratospheric warming events, Weather Clim. Dynam., 1, 373–388, https://doi.org/10.5194/wcd-1-373-2020, 2020b. a
González-Alemán, J. J., Grams, C. M., Ayarzagüena, B., Zurita-Gotor, P., Domeisen, D. I., Gómara, I., Rodríguez-Fonseca, B., and Vitart, F.: Tropospheric role in the predictability of the surface impact of the 2018 sudden stratospheric warming event, Geophys. Res. Lett., 49, e2021GL095464, https://doi.org/10.1029/2021GL095464, 2022. a
Goss, M., Lindgren, E. A., Sheshadri, A., and Diffenbaugh, N. S.: The Atlantic jet response to stratospheric events: a regime perspective, J. Geophys. Res.-Atmos., 126, e2020JD033358, https://doi.org/10.1029/2020JD033358, 2021. a
Guo, Y., Shinoda, T., Lin, J., and Chang, E. K.: Variations of Northern Hemisphere storm track and extratropical cyclone activity associated with the Madden–Julian oscillation, J. Climate, 30, 4799–4818, 2017. a
Hansen, F., Kruschke, T., Greatbatch, R. J., and Weisheimer, A.: Factors influencing the seasonal predictability of Northern Hemisphere severe winter storms, Geophys. Res. Lett., 46, 365–373, 2019. a
Harvey, B., Cook, P., Shaffrey, L., and Schiemann, R.: The response of the northern hemisphere storm tracks and jet streams to climate change in the CMIP3, CMIP5, and CMIP6 climate models, J. Geophys. Res.-Atmos., 125, e2020JD032701, https://doi.org/10.1029/2020JD032701, 2020. a
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. a, b
Hersbach, H., Bell, B., Berrisford, P., Biavati, G., Horányi, A., Muñoz Sabater, J., Nicolas, J., Peubey, C., Radu, R., Rozum, I., Schepers, D., Simmons, A., Soci, C., Dee, D., and Thépaut, J-N.: ERA5 hourly data on pressure levels from 1940 to present, Copernicus Climate Change Service (C3S) Climate Data Store (CDS) [data set], https://doi.org/10.24381/cds.bd0915c6, 2023. a
Hoskins, B. J. and Hodges, K. I.: New perspectives on the Northern Hemisphere winter storm tracks, J. Atmos. Sci., 59, 1041–1061, 2002. a
Hoskins, B. J. and Hodges, K. I.: A new perspective on Southern Hemisphere storm tracks, J. Climate, 18, 4108–4129, 2005. a
Kautz, L.-A., Martius, O., Pfahl, S., Pinto, J. G., Ramos, A. M., Sousa, P. M., and Woollings, T.: Atmospheric blocking and weather extremes over the Euro-Atlantic sector – a review, Weather Clim. Dynam., 3, 305–336, https://doi.org/10.5194/wcd-3-305-2022, 2022. a
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. a
Kolstad, E., Lee, S., Butler, A., Domeisen, D., and Wulff, C.: Diverse surface signatures of stratospheric polar vortex anomalies, J. Geophys. Res.-Atmos., 127, e2022JD037422, https://doi.org/10.1029/2022JD037422, 2022. a
Kolstad, E. W., Wulff, C. O., Domeisen, D. I. V., and Woollings, T.: Tracing North Atlantic Oscillation forecast errors to stratospheric origins, J. Climate, 33, 9145–9157, 2020. a
Lawrence, Z. D., Perlwitz, J., Butler, A. H., Manney, G. L., Newman, P. A., Lee, S. H., and Nash, E. R.: The remarkably strong Arctic stratospheric polar vortex of winter 2020: Links to record-breaking Arctic oscillation and ozone loss, J. Geophys. Res.-Atmos., 125, e2020JD033271, https://doi.org/10.1029/2020JD033271, 2020. a
Lee, S. H., Lawrence, Z. D., Butler, A. H., and Karpechko, A. Y.: Seasonal forecasts of the exceptional Northern Hemisphere winter of 2020, Geophys. Res. Lett., 47, e2020GL090328, https://doi.org/10.1029/2020GL090328, 2020. a
Lee, S. H., Polvani, L. M., and Guan, B.: Modulation of Atmospheric Rivers by the Arctic Stratospheric Polar Vortex, Geophys. Res. Lett., e2022GL100381, https://doi.org/10.1029/2022GL100381, 2022. a
Oehrlein, J., Chiodo, G., and Polvani, L. M.: The effect of interactive ozone chemistry on weak and strong stratospheric polar vortex events, Atmos. Chem. Phys., 20, 10531–10544, https://doi.org/10.5194/acp-20-10531-2020, 2020. a
Pfahl, S., Schwierz, C., Croci-Maspoli, M., Grams, C. M., and Wernli, H.: Importance of latent heat release in ascending air streams for atmospheric blocking, Nat. Geosci., 8, 610–614, 2015. a
Priestley, M. D. K. and Catto, J. L.: Future changes in the extratropical storm tracks and cyclone intensity, wind speed, and structure, Weather Clim. Dynam., 3, 337–360, https://doi.org/10.5194/wcd-3-337-2022, 2022. a
Rivière, G., Arbogast, P., Lapeyre, G., and Maynard, K.: A potential vorticity perspective on the motion of a mid-latitude winter storm, Geophys. Res. Lett., 39, L12808, https://doi.org/10.1029/2012GL052440, 2012. a
Rupp, P., Loeffel, S., Garny, H., Chen, X., Pinto, J. G., and Birner, T.: Potential Links Between Tropospheric and Stratospheric Circulation Extremes During Early 2020, J. Geophys. Res.-Atmos., 127, e2021JD035667, https://doi.org/10.1029/2021JD035667, 2022. a, b
Scaife, A. A., Arribas, A., Blockley, E., Brookshaw, A., Clark, R. T., Dunstone, N., Eade, R., Fereday, D., Folland, C. K., Gordon, M., Hermanson, L., Knight, J. R., Lea, D. J., MacLachlan, C., Maidens, A., Martin, M., Peterson, A. K., Smith, D., Vellinga, M., Wallace, E., Waters, J., and Williams, A.: Skillful long-range prediction of European and North American winters, Geophys. Res. Lett., 41, 2514–2519, 2014. a
Scaife, A. A., Knight, J. R., Vallis, G. K., and Folland, C. K.: A stratospheric influence on the winter NAO and North Atlantic surface climate, Geophys. Res. Lett., 32, https://doi.org/10.1029/2005GL023226, 2005. a
Shaw, T. A., Baldwin, M., Barnes, E. A., Caballero, R., Garfinkel, C. I., Hwang, Y.-T., Li, C., O'Gorman, P. A., Rivière, G., Simpson, I. R., and Voigt, A.: Storm track processes and the opposing influences of climate change, Nat. Geosci., 9, 656–664, https://doi.org/10.1038/ngeo2783, 2016. a
Steinfeld, D. and Pfahl, S.: The role of latent heating in atmospheric blocking dynamics: a global climatology, Clim. Dynam., 53, 6159–6180, 2019. a
Stockdale, T. N., Molteni, F., and Ferranti, L.: Atmospheric initial conditions and the predictability of the Arctic Oscillation, Geophys. Res. Lett., 42, 1173–1179, 2015. a
Tamarin, T. and Kaspi, Y.: The poleward motion of extratropical cyclones from a potential vorticity tendency analysis, J. Atmos. Sci., 73, 1687–1707, 2016. a
Vitart, F., Ardilouze, C., Bonet, A., Brookshaw, A., Chen, M., Codorean, C., Déqué, M., Ferranti, L., Fucile, E., Fuentes, M., Hendon, H., Hodgson, J., Kang, H., Kumar, A., Lin, H., Liu, G., Liu, X., Malguzzi, P., Mallas, I., Manoussakis, M., Mastrangelo, D., MacLachlan, C., McLean, P., Minami, A., Mladek, R., Nakazawa, T., Najm, S., Nie, Y., Rixen, M., Robertson, A. W., Ruti, P., Sun, C., Takaya, Y., Tolstykh, M., Venuti, F., Waliser, D., Woolnough, S., Wu, T., Won, D., Xiao, H., Zaripov, R., and Zhang, L.: The subseasonal to seasonal (S2S) prediction project database, B. Am. Meteorol. Soc., 98, 163–173, https://doi.org/10.1175/BAMS-D-16-0017.1, 2017 (data available at: https://apps.ecmwf.int/datasets/data/s2s). a
Wernli, H. and Schwierz, C.: Surface cyclones in the ERA-40 dataset (1958–2001). Part I: Novel identification method and global climatology, J. Atmos. Sci., 63, 2486–2507, 2006. a
Zheng, C., Kar-Man Chang, E., Kim, H.-M., Zhang, M., and Wang, W.: Impacts of the Madden–Julian oscillation on storm-track activity, surface air temperature, and precipitation over North America, J. Climate, 31, 6113–6134, 2018. a
Short summary
The stratosphere is a layer of Earth's atmosphere found above the weather systems. Changes in the stratosphere can affect the winds and the storm tracks in the North Atlantic region for a relatively long time, lasting for several weeks and even months. We show that the stratosphere can be important for weather forecasts beyond 1 week, but more work is needed to improve the accuracy of these forecasts for 3–4 weeks.
The stratosphere is a layer of Earth's atmosphere found above the weather systems. Changes in...
