Articles | Volume 2, issue 4
https://doi.org/10.5194/wcd-2-991-2021
© Author(s) 2021. 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-2-991-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
27 Oct 2021
Research article |
| 27 Oct 2021
| 27 Oct 2021
A global analysis of the dry-dynamic forcing during cyclone growth and propagation
Philippe Besson
CORRESPONDING AUTHOR
Institute for Atmospheric and Climate Science, ETH Zürich, Zurich, Switzerland
Luise J. Fischer
Institute for Atmospheric and Climate Science, ETH Zürich, Zurich, Switzerland
Institute for Environmental Decisions, ETH Zürich, Zurich, Switzerland
Sebastian Schemm
Institute for Atmospheric and Climate Science, ETH Zürich, Zurich, Switzerland
Michael Sprenger
CORRESPONDING AUTHOR
Institute for Atmospheric and Climate Science, ETH Zürich, Zurich, Switzerland
Related authors
No articles found.
Nora Zilibotti, Heini Wernli, and Sebastian Schemm
Weather Clim. Dynam., 7, 201–221, https://doi.org/10.5194/wcd-7-201-2026, https://doi.org/10.5194/wcd-7-201-2026, 2026
Short summary
Short summary
This study investigates the relationship between jet strength and storm track activity in the North Pacific and North Atlantic with a new approach that does not rely on monthly averaging. We find a consistent behaviour in the two basins, with two distinct relationships on seasonal and sub-monthly timescales emerging. This work underlines the importance of separating different timescales of variability to understand the interplay of jet characteristics and storm track activity.
Anurag Dipankar, Mauro Bianco, Mona Bukenberger, Till Ehrengruber, Nicoletta Farabullini, Oliver Fuhrer, Abishek Gopal, Daniel Hupp, Andreas Jocksch, Samuel Kellerhals, Clarissa A. Kroll, Xavier Lapillonne, Matthieu Leclair, Magdalena Luz, Christoph Müller, Chia Rui Ong, Carlos Osuna, Praveen Pothapakula, Andreas Prein, Matthias Röthlin, William Sawyer, Christoph Schär, Sebastian Schemm, Giacomo Serafini, Hannes Vogt, Ben Weber, Robert C. Jnglin Wills, Nicolas Gruber, and Thomas C. Schulthess
Geosci. Model Dev., 19, 713–729, https://doi.org/10.5194/gmd-19-713-2026, https://doi.org/10.5194/gmd-19-713-2026, 2026
Short summary
Short summary
Climate models are becoming more detailed and accurate by simulating weather at scales of just a few kilometers. Simulating at km-scale is computationally demanding requiring powerful supercomputers and efficient code. This work presents a refactored dynamical core of a state-of-the-art climate model using a Python-based approach. The refactored code has passed through a sequence of verification and validation demonstrating its usability in performing km-scale global simulations.
Jacopo Riboldi, Robin Noyelle, Ellina Agayar, Hanin Binder, Marc Federer, Katharina Hartmuth, Michael Sprenger, Iris Thurnherr, and Selvakumar Vishnupriya
Weather Clim. Dynam., 7, 65–87, https://doi.org/10.5194/wcd-7-65-2026, https://doi.org/10.5194/wcd-7-65-2026, 2026
Short summary
Short summary
Storm Boris led to record-breaking precipitation over central Europe in September 2024. By incorporating event-specific meteorological information, this work introduces a methodology to strengthen our comprehension of how global warming affects similar hazards. 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 attribution research.
Ellina Agayar, Moshe Armon, Michael Sprenger, and Heini Wernli
EGUsphere, https://doi.org/10.5194/egusphere-2025-5942, https://doi.org/10.5194/egusphere-2025-5942, 2025
This preprint is open for discussion and under review for Natural Hazards and Earth System Sciences (NHESS).
Short summary
Short summary
This study examines the hydrometeorological features of the major floods of 2008, 2010, and 2020 in western Ukraine. All cases were linked to upper-level PV anomalies. We also conducted a climatological analysis of PV structure associated with 22 summer heavy precipitation cases (2000–2022), highlighting their key role in determining the location and intensity of flood-inducing rainfall events in the Carpathians.
Ming Hon Franco Lee and Michael Sprenger
Weather Clim. Dynam., 6, 1583–1604, https://doi.org/10.5194/wcd-6-1583-2025, https://doi.org/10.5194/wcd-6-1583-2025, 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.
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
Weather Clim. Dynam., 6, 1515–1538, https://doi.org/10.5194/wcd-6-1515-2025, https://doi.org/10.5194/wcd-6-1515-2025, 2025
Short summary
Short summary
Storm Daniel (2023) is one of the most catastrophic storms 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 an analysis of the storm by articulating dynamics, weather prediction, hydrological and oceanographic implications, climate extremes, and attribution theory.
Tuule Müürsepp, Michael Sprenger, Heini Wernli, and Hanna Joos
EGUsphere, https://doi.org/10.5194/egusphere-2025-5224, https://doi.org/10.5194/egusphere-2025-5224, 2025
Short summary
Short summary
The tropopause region of the atmosphere is greatly impacted by the exchange of mass and constituents between the troposphere and the stratosphere. This study quantifies the role of radiation in troposphere-to-stratosphere transport using reanalysis data. We find that radiation contributes to this transport most of the time, albeit it might not be the dominant process. We provide a new insight into the complex interplay of processes that air parcels experience on their way to the stratosphere.
Matthias Röthlisberger, Michael Sprenger, Urs Beyerle, Erich M. Fischer, and Heini Wernli
EGUsphere, https://doi.org/10.5194/egusphere-2025-5146, https://doi.org/10.5194/egusphere-2025-5146, 2025
Short summary
Short summary
This study investigates yearly heat extremes simulated with the global climate model CESM2. A trajectory-based method is used, which allows quantifying the contributions to temperature anomalies from advection, subsidence, and diabatic heating. The results show that the magnitude of CESM2 heat extremes agrees fairly well with ERA5 reanalyses, but it is often “right for the partly wrong physical reasons”.
Selvakumar Vishnupriya, Michael Sprenger, Hanna Joos, and Heini Wernli
Weather Clim. Dynam., 6, 1195–1219, https://doi.org/10.5194/wcd-6-1195-2025, https://doi.org/10.5194/wcd-6-1195-2025, 2025
Short summary
Short summary
Extratropical cyclones feature rapidly ascending airstreams known as warm conveyor belts, which could influence upper-level flow dynamics. This study classifies interactions between warm conveyor belt outflows and the jet stream into four types: no interactions, ridges, blocks, and tropospheric cutoffs. We use reanalysis data to demonstrate that the interaction type depends on the structure of the ambient flow than on the outflow, improving our understanding of extratropical flow variability.
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.
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.
Jan Zibell, Alejandro Hermoso, Aaron Donohoe, and Sebastian Schemm
EGUsphere, https://doi.org/10.5194/egusphere-2025-2314, https://doi.org/10.5194/egusphere-2025-2314, 2025
Short summary
Short summary
The high-frequent moist static energy (MSE) flux dominates poleward atmospheric heat transport in the Southern Hemisphere. In this study, we investigate how this high-frequent eddy MSE flux evolves over the life cycle of extratropical cyclones. By attributing eddy MSE fluxes to nearby cyclones, we assess the contribution of individual cyclones to zonally integrated atmospheric heat transport and discuss the relationship between cyclone numbers and atmospheric heat transport on a seasonal scale.
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
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.
Mona Bukenberger, Lena Fasnacht, Stefan Rüdisühli, and Sebastian Schemm
Weather Clim. Dynam., 6, 279–316, https://doi.org/10.5194/wcd-6-279-2025, https://doi.org/10.5194/wcd-6-279-2025, 2025
Short summary
Short summary
The jet stream is a band of strong westerly winds, within which jet streaks are regions of faster wind speeds that can aid storm development. This study analyses jet streaks over the North Atlantic during winter. Jet streaks are linked to pairs of surface anticyclones and cyclones and are often accompanied by intense precipitation, especially extreme jet streaks. With cloud processes playing an increased role in extreme jet streaks, follow-up studies concerning their role are warranted.
Victoria M. Bauer, Sebastian Schemm, Raphael Portmann, Jingzhi Zhang, Gesa K. Eirund, Steven J. De Hertog, and Jan Zibell
Earth Syst. Dynam., 16, 379–409, https://doi.org/10.5194/esd-16-379-2025, https://doi.org/10.5194/esd-16-379-2025, 2025
Short summary
Short summary
Past research has shown that the North Atlantic Ocean circulation reacts strongly to global forest cover changes. Using Earth system model simulations featuring idealised forestation and deforestation of North America, this study shows that the North Atlantic Ocean is highly sensitive to upstream land cover changes. Anomalies in air temperature over land propagate downstream and modify ocean-to-atmosphere heat fluxes over the North Atlantic through altering the cold-air outbreak frequency.
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.
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.
Bjorn Stevens, Stefan Adami, Tariq Ali, Hartwig Anzt, Zafer Aslan, Sabine Attinger, Jaana Bäck, Johanna Baehr, Peter Bauer, Natacha Bernier, Bob Bishop, Hendryk Bockelmann, Sandrine Bony, Guy Brasseur, David N. Bresch, Sean Breyer, Gilbert Brunet, Pier Luigi Buttigieg, Junji Cao, Christelle Castet, Yafang Cheng, Ayantika Dey Choudhury, Deborah Coen, Susanne Crewell, Atish Dabholkar, Qing Dai, Francisco Doblas-Reyes, Dale Durran, Ayoub El Gaidi, Charlie Ewen, Eleftheria Exarchou, Veronika Eyring, Florencia Falkinhoff, David Farrell, Piers M. Forster, Ariane Frassoni, Claudia Frauen, Oliver Fuhrer, Shahzad Gani, Edwin Gerber, Debra Goldfarb, Jens Grieger, Nicolas Gruber, Wilco Hazeleger, Rolf Herken, Chris Hewitt, Torsten Hoefler, Huang-Hsiung Hsu, Daniela Jacob, Alexandra Jahn, Christian Jakob, Thomas Jung, Christopher Kadow, In-Sik Kang, Sarah Kang, Karthik Kashinath, Katharina Kleinen-von Königslöw, Daniel Klocke, Uta Kloenne, Milan Klöwer, Chihiro Kodama, Stefan Kollet, Tobias Kölling, Jenni Kontkanen, Steve Kopp, Michal Koran, Markku Kulmala, Hanna Lappalainen, Fakhria Latifi, Bryan Lawrence, June Yi Lee, Quentin Lejeun, Christian Lessig, Chao Li, Thomas Lippert, Jürg Luterbacher, Pekka Manninen, Jochem Marotzke, Satoshi Matsouoka, Charlotte Merchant, Peter Messmer, Gero Michel, Kristel Michielsen, Tomoki Miyakawa, Jens Müller, Ramsha Munir, Sandeep Narayanasetti, Ousmane Ndiaye, Carlos Nobre, Achim Oberg, Riko Oki, Tuba Özkan-Haller, Tim Palmer, Stan Posey, Andreas Prein, Odessa Primus, Mike Pritchard, Julie Pullen, Dian Putrasahan, Johannes Quaas, Krishnan Raghavan, Venkatachalam Ramaswamy, Markus Rapp, Florian Rauser, Markus Reichstein, Aromar Revi, Sonakshi Saluja, Masaki Satoh, Vera Schemann, Sebastian Schemm, Christina Schnadt Poberaj, Thomas Schulthess, Cath Senior, Jagadish Shukla, Manmeet Singh, Julia Slingo, Adam Sobel, Silvina Solman, Jenna Spitzer, Philip Stier, Thomas Stocker, Sarah Strock, Hang Su, Petteri Taalas, John Taylor, Susann Tegtmeier, Georg Teutsch, Adrian Tompkins, Uwe Ulbrich, Pier-Luigi Vidale, Chien-Ming Wu, Hao Xu, Najibullah Zaki, Laure Zanna, Tianjun Zhou, and Florian Ziemen
Earth Syst. Sci. Data, 16, 2113–2122, https://doi.org/10.5194/essd-16-2113-2024, https://doi.org/10.5194/essd-16-2113-2024, 2024
Short summary
Short summary
To manage Earth in the Anthropocene, new tools, new institutions, and new forms of international cooperation will be required. Earth Virtualization Engines is proposed as an international federation of centers of excellence to empower all people to respond to the immense and urgent challenges posed by climate change.
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.
Steven J. De Hertog, Carmen E. Lopez-Fabara, Ruud van der Ent, Jessica Keune, Diego G. Miralles, Raphael Portmann, Sebastian Schemm, Felix Havermann, Suqi Guo, Fei Luo, Iris Manola, Quentin Lejeune, Julia Pongratz, Carl-Friedrich Schleussner, Sonia I. Seneviratne, and Wim Thiery
Earth Syst. Dynam., 15, 265–291, https://doi.org/10.5194/esd-15-265-2024, https://doi.org/10.5194/esd-15-265-2024, 2024
Short summary
Short summary
Changes in land use are crucial to achieve lower global warming. However, despite their importance, the effects of these changes on moisture fluxes are poorly understood. We analyse land cover and management scenarios in three climate models involving cropland expansion, afforestation, and irrigation. Results show largely consistent influences on moisture fluxes, with cropland expansion causing a drying and reduced local moisture recycling, while afforestation and irrigation show the opposite.
Hilla Afargan-Gerstman, Dominik Büeler, C. Ole Wulff, Michael Sprenger, and Daniela I. V. Domeisen
Weather Clim. Dynam., 5, 231–249, https://doi.org/10.5194/wcd-5-231-2024, https://doi.org/10.5194/wcd-5-231-2024, 2024
Short summary
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.
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.
Sebastian Schemm and Matthias Röthlisberger
Weather Clim. Dynam., 5, 43–63, https://doi.org/10.5194/wcd-5-43-2024, https://doi.org/10.5194/wcd-5-43-2024, 2024
Short summary
Short summary
Climate change has started to weaken atmospheric circulation during summer in the Northern Hemisphere. However, there is low agreement on the processes underlying changes in, for example, the stationarity of weather patterns or the seasonality of the jet response to warming. This study examines changes during summertime in an idealised setting and confirms some important changes in hemisphere-wide wave and jet characteristics under warming.
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.
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.
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.
Steven J. De Hertog, Carmen E. Lopez-Fabara, Ruud van der Ent, Jessica Keune, Diego G. Miralles, Raphael Portmann, Sebastian Schemm, Felix Havermann, Suqi Guo, Fei Luo, Iris Manola, Quentin Lejeune, Julia Pongratz, Carl-Friedrich Schleussner, Sonia I. Seneviratne, and Wim Thiery
EGUsphere, https://doi.org/10.5194/egusphere-2023-953, https://doi.org/10.5194/egusphere-2023-953, 2023
Preprint archived
Short summary
Short summary
Land cover and management changes can affect the climate and water availability. In this study we use climate model simulations of extreme global land cover changes (afforestation, deforestation) and land management changes (irrigation) to understand the effects on the global water cycle and local to continental water availability. We show that cropland expansion generally leads to higher evaporation and lower amounts of precipitation and afforestation and irrigation expansion to the opposite.
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.
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.
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.
Sebastian Schemm, Lukas Papritz, and Gwendal Rivière
Weather Clim. Dynam., 3, 601–623, https://doi.org/10.5194/wcd-3-601-2022, https://doi.org/10.5194/wcd-3-601-2022, 2022
Short summary
Short summary
Much of the change in our daily weather patterns is due to the development and intensification of extratropical cyclones. The response of these systems to climate change is an important topic of ongoing research. This study is the first to reproduce the changes in the North Atlantic circulation and extratropical cyclone characteristics found in fully coupled Earth system models under high-CO2 scenarios, but in an idealized, reduced-complexity simulation with uniform warming.
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.
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.
Gabriel Vollenweider, Elisa Spreitzer, and Sebastian Schemm
Weather Clim. Dynam. Discuss., https://doi.org/10.5194/wcd-2021-31, https://doi.org/10.5194/wcd-2021-31, 2021
Publication in WCD not foreseen
Short summary
Short summary
The interactions between the dry and moist components of the atmosphere and the influence of, for example, the phase transition of water on the atmospheric circulation are often studied from the potential vorticity (PV) framework. Changes in the PV due to, for example, condensation can relate to changes in the static stability or vorticity. To better the interaction between these two drivers of PV changes, we explore the usefulness of a novel vorticity-and-stability diagram.
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.
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.
Cited articles
Avila, L. A., Pasch, R. J., and Jiing, J.-G.: Atlantic tropical systems of 1996 and 1997: Years of contrasts, Mon. Weather Rev., 128, 3695–3706, https://doi.org/10.1175/1520-0493(2000)128<3695:ATSOAY>2.0.CO;2, 2000. a
Bengtsson, L., Hodges, K. I., and Keenlyside, N.: Will extratropical storms intensify in a warmer climate?, J. Climate, 22, 2276–2301, https://doi.org/10.1175/2008JCLI2678.1, 2009. a, b
Binder, H., Boettcher, M., Joos, H., and Wernli, H.: The role of warm conveyor belts for the intensification of extratropical cyclones in Northern Hemisphere winter, J. Atmos. Sci., 73, 3997–4020, https://doi.org/10.1175/JAS-D-15-0302.1, 2016. a
Boettcher, M. and Wernli, H.: A 10-yr Climatology of diabatic Rossby waves in the Northern Hemisphere, Mon. Weather Rev., 141, 1139–1154, https://doi.org/10.1175/MWR-D-12-00012.1, 2013. a, b
Browning, K. A.: Organization of Clouds and Precipitation in Extratropical Cyclones, in: Extratropical Cyclones, edited by: Newton, C. W. and Holopainen, E. O., American Meteorological Society, Boston, MA, https://doi.org/10.1007/978-1-944970-33-8_8, 1990. a
Büler, D. and Pfahl, S.: Potential vorticity diagnostics to quantify effects of latent heating in extratropical cyclones. Part I: Methodology, J. Atmos. Sci., 74, 3567–3590, https://doi.org/10.1175/JAS-D-17-0041.1, 2017. a
Burpee, R. W.: The origin and structure of easterly waves in the lower troposphere of North Africa, J. Atmos. Sci., 29, 77–90, https://doi.org/10.1175/1520-0469(1972)029<0077:TOASOE>2.0.CO;2, 1972. a
Čampa, J. and Wernli, H.: A PV perspective on the vertical structure of mature midlatitude cyclones in the Northern Hemisphere, J. Atmos. Sci., 69, 725–740, https://doi.org/10.1175/JAS-D-11-050.1, 2012. a
Caruso, S. J. and Businger, S.: Subtropical cyclogenesis over the central North Pacific, Weather Forecast., 21, 193–205, https://doi.org/10.1175/WAF914.1, 2006. a, b
Catto, J. L.: A new method to objectively classify extratropical cyclones for climate studies: Testing in the southwest Pacific region, J. Climate, 31, 4683–4704, https://doi.org/10.1175/JCLI-D-17-0746.1, 2018. a
Cavallo, S. M. and Hakim, G. J.: Potential vorticity diagnosis of a tropopause polar cyclone, Mon. Weather Rev., 137, 1358–1371, https://doi.org/10.1175/2008MWR2670.1, 2009. a
Chang, E. K. M.: The impact of wave packets propagating across Asia on Pacific cyclone development, Mon. Weather Rev., 133, 1998–2015, https://doi.org/10.1175/MWR2953.1, 2005. a, b
Chang, E. K. M. and Guo, Y.: Is Pacific Storm-Track Activity Correlated with the Strength of Upstream Wave Seeding?, J. Climate, 25, 5768–5776, https://doi.org/10.1175/JCLI-D-11-00555.1, 2012. a
Chang, E. K. M., Lee, S., and Swanson, K. L.: Storm track dynamics, J. Climate, 15, 2163–2183, https://doi.org/10.1175/1520-0442(2002)015<02163:STD>2.0.CO;2, 2002. a
Charney, J. G.: The dynamics of long waves in a baroclinic westerly current, J. Meteorol., 4, 136–162, https://doi.org/10.1175/1520-0469(1947)004<0136:TDOLWI>2.0.CO;2, 1947. a
Chung, Y.-S. and Reinelt, E. R.: On cyclogenesis in the lee of the Canadian Rocky Mountains, Arch. Meteor. Geophy. A, 22, 205–226, https://doi.org/10.1007/BF02247545, 1973. a
Coronel, B., Ricard, D., Rivière, G., and Arbogast, P.: Role of moist processes in the tracks of idealized midlatitude surface cyclones, J. Atmos. Sci., 72, 2979–2996, https://doi.org/10.1175/JAS-D-14-0337.1, 2015. a
Dacre, H. F. and Gray, S. L.: Quantifying the climatological relationship between extratropical cyclone intensity and atmospheric precursors, Geophys. Res. Lett., 40, 2322–2327, https://doi.org/10.1002/grl.50105, 2013. a
Davies, H. C.: The quasigeostrophic omega equation: Reappraisal, refinements, and relevance, Mon. Weather Rev., 143, 3–25, https://doi.org/10.1175/MWR-D-14-00098.1, 2015. a
Davis, C. A.: A potential-vorticity diagnosis of the importance of initial structure and condensational heating in observed extratropical cyclogenesis, Mon. Weather Rev., 120, 2409–2428, https://doi.org/10.1175/1520-0493(1992)120<2409:APVDOT>2.0.CO;2, 1992. a
Deveson, A., Browning, K., and Hewson, T.: A classification of FASTEX cyclones using a height-attributable quasi-geostrophic vertical-motion diagnostic, Q. J. Roy. Meteor. Soc., 128, 93–117, https://doi.org/10.1256/00359000260498806, 2002. a, b
Eady, E. T.: Long waves and cyclone waves, Tellus, 1, 33–52, https://doi.org/10.1111/j.2153-3490.1949.tb01265.x, 1949. a
Evans, J. L. and Braun, A.: A climatology of subtropical cyclones in the South Atlantic, J. Climate, 25, 7328–7340, https://doi.org/10.1175/JCLI-D-11-00212.1, 2012. a
Evans, J. L. and Guishard, M. P.: Atlantic subtropical storms. Part I: Diagnostic criteria and composite analysis, Mon. Weather Rev., 137, 2065–2080, https://doi.org/10.1175/2009MWR2468.1, 2009. a
Gachon, P., Laprise, R., Zwack, P., and Saucier, F. J.: The effects of interactions between surface forcings in the development of a model-simulated polar low in Hudson Bay, Tellus, 55, 61–87, https://doi.org/10.3402/tellusa.v55i1.12079, 2003. a
Gilet, J.-B., Plu, M., and Rivière, G.: Nonlinear baroclinic dynamics of surface cyclones crossing a zonal jet, J. Atmos. Sci., 66, 3021–3041, https://doi.org/10.1175/2009JAS3086.1, 2009. a, b, c
Graf, M. A., Wernli, H., and Sprenger, M.: Objective classification of extratropical cyclogenesis, Q. J. Roy. Meteor. Soc., 143, 1047–1061, https://doi.org/10.1002/qj.2989, 2017. a, b, c
Gray, S. L. and Dacre, H. F.: Classifying dynamical forcing mechanisms using a climatology of extratropical cyclones, Q. J. Roy. Meteor. Soc., 132, 1119–1137, https://doi.org/10.1256/qj.05.69, 2006. a, b
Guishard, M. P., Evans, J. L., and Hart, R. E.: Atlantic subtropical storms. Part II: Climatology, J. Climate, 22, 3574–3594, https://doi.org/10.1175/2008JCLI2346.1, 2009. a
Hart, R. E.: A cyclone phase space derived from thermal wind and thermal asymmetry, Mon. Weather Rev., 131, 585–616, https://doi.org/10.1175/1520-0493(2003)131<0585:ACPSDF>2.0.CO;2, 2003. a
Hoskins, B. J. and Hodges, K. I.: New perspectives on the Northern Hemisphere winter storm tracks, J. Atmos. Sci., 59, 1041–1061, https://doi.org/10.1175/1520-0469(2002)059<1041:NPOTNH>2.0.CO;2, 2002. a, b, c, d
Hoskins, B. J. and Pedder, M. A.: The diagnosis of middle latitude synoptic development, Q. J. Roy. Meteor. Soc., 106, 707–719, https://doi.org/10.1002/qj.49710645004, 1980. a, b
Hoskins, B. J., Draghici, I., and Davies, H. C.: A new look at the ω-equation, Q. J. Roy. Meteor. Soc., 104, 31–38, https://doi.org/10.1002/qj.49710443903, 1978. a, b
Hoskins, B. J., McIntyre, M. E., and Robertson, A. W.: On the use and significance of isentropic potential vorticity maps, Q. J. Roy. Meteor. Soc., 111, 877–946, https://doi.org/10.1002/qj.49711147002, 1985. a, b, c
Joly, A. and Thorpe, A. J.: Frontal instability generated by tropospheric potential vorticity anomalies, Q. J. Roy. Meteor. Soc., 116, 525–560, 1990. a
Jones, D. A. and Simmonds, I.: A climatology of Southern Hemisphere extratropical cyclones, Clim. Dynam., 9, 131–145, 1993. a
Kuo, Y.-H., Shapiro, M. A., and Donall, E. G.: The interaction between baroclinic and diabatic processes in a numerical simulation of a rapidly intensifying extratropical marine cyclone, Mon. Weather Rev., 119, 368–384, https://doi.org/10.1175/1520-0493(1991)119<0368:TIBBAD>2.0.CO;2, 1990. a
Lambert, S. J. and Fyfe, J. C.: Changes in winter cyclone frequencies and strengths simulated in enhanced greenhouse warming experiments: Results from the models participating in the IPCC diagnostic exercise, Clim. Dynam., 26, 713–728, https://doi.org/10.1007/s00382-006-0110-3, 2006. a
Lindzen, R. S. and Farrell, B.: A simple approximate result for the maximum growth rate of baroclinic instabilities, J. Atmos. Sci., 37, 1648–1654, https://doi.org/10.1175/1520-0469(1980)037<1648:ASARFT>2.0.CO;2, 1980. a, b, c
Mansfield, D. A.: Polar lows: The development of baroclinic disturbances in cold air outbreaks, Q. J. Roy. Meteor. Soc., 100, 541–554, https://doi.org/10.1002/qj.49710042604, 1974. a
McTaggart-Cowan, R., Deane, G. D., Bosart, L. F., Davis, C. A., and Galarneau, T. J.: Climatology of tropical cyclogenesis in the North Atlantic (1948–2004), Mon. Weather Rev., 136, 1284–1304, https://doi.org/10.1175/2007MWR2245.1, 2008. a
Moore, R. W., Martius, O., and Davies, H. C.: Downstream development and Kona low genesis, Geophys. Res. Lett., 35, L20814, https://doi.org/10.1029/2008GL035502, 2008. a
Morrison, I. and Businger, S.: Synoptic structure and evolution of a Kona Low, Weather Forecast., 16, 81–98, https://doi.org/10.1175/1520-0434(2001)016<0081:SSAEOA>2.0.CO;2, 2001. a
Otkin, J. A. and Martin, J. E.: A synoptic climatology of the subtropical Kona storm, Mon. Weather Rev., 132, 1502–1517, https://doi.org/10.1175/1520-0493(2004)132<1502:ASCOTS>2.0.CO;2, 2004. a
Pascal, R. and Sprenger, M.: Bericht zum Programm zur Berechnung der diagnostischen, quasigeostrophischen Vertikalgeschwindigkeit, Tech. rep., Institut for Atmospheric and Climate Science, ETH Zürich, https://doi.org/10.3929/ethz-b-000500755, available in German, 2009. a
Petterssen, S. and Smebye, S.: On the development of extratropical cyclones, Q. J. Roy. Meteor. Soc., 97, 457–482, https://doi.org/10.1002/qj.49709741407, 1971. a, b, c
Portmann, R., Sprenger, M., and Wernli, H.: The three-dimensional life cycles of potential vorticity cutoffs: a global and selected regional climatologies in ERA-Interim (1979–2018), Weather Clim. Dynam., 2, 507–534, https://doi.org/10.5194/wcd-2-507-2021, 2021. a
Priestley, M. D. K., Dacre, H. F., Shaffrey, L. C., Schemm, S., and Pinto, J. G.: The role of secondary cyclones and cyclone families for the North Atlantic storm track and clustering over western Europe, Q. J. Roy. Meteor. Soc., 146, 1184–1205, https://doi.org/10.1002/qj.3733, 2020. a, b
Rasmussen, E. and Turner, J.: Polar Lows: Mesoscale Weather Systems in the Polar Regions, Cambridge University Press, Cambridge, https://doi.org/10.1017/CBO9780511524974, 2003. a
Reed, R. J., Stoelinga, M. T., and Kuo, Y.-H.: A model-aided study of the origin and evolution of the anomalously high potential vorticity in the inner region of a rapidly deepening marine cyclone, Mon. Weather Rev., 120, 893–913, https://doi.org/10.1175/1520-0493(1992)120<0893:AMASOT>2.0.CO;2, 1992. 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, b, c
Rogers, E. and Bosart, L. F.: An investigation of explosively deepening oceanic cyclones, Mon. Weather Rev., 114, 702–718, https://doi.org/10.1175/1520-0493(1986)114<0702:AIOEDO>2.0.CO;2, 1986. a, b
Schär, C. and Davies, H. C.: An instability of mature cold fronts, J. Atmos. Sci., 47, 929–950, 1990. a
Schemm, S. and Rivière, G.: On the efficiency of baroclinic eddy growth and how it reduces the North Pacific storm-track intensity in midwinter, J. Climate, 32, 8373–8398, https://doi.org/10.1175/JCLI-D-19-0115.1, 2019. a, b
Schemm, S. and Sprenger, M.: Frontal-wave cyclogenesis in the North Atlantic – a climatological characterisation, Q. J. Roy. Meteor. Soc., 141, 2989–3005, https://doi.org/10.1002/qj.2584, 2015. a, b
Schemm, S., Wernli, H., and Papritz, L.: Warm conveyor belts in idealized moist baroclinic wave simulations, J. Atmos. Sci., 70, 627–652, https://doi.org/10.1175/JAS-D-12-0147.1, 2013. a
Schemm, S., Sprenger, M., and Wernli, H.: When during their life cycle are extratropical cyclones attended by fronts?, B. Am. Meteorol. Soc., 99, 149–165, https://doi.org/10.1175/BAMS-D-16-0261.1, 2018. a, b
Semple, A. T.: A review and unification of conceptual models of cyclogenesis, Meteorol. Appl., 10, 39–59, 2003. a
Shaw, T., Baldwin, M., Barnes, E. A., Caballero, R., Garfinkel, C., Hwang, Y.-T., Li, C., O'Gorman, P., Rivière, G., Simpson, I., 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
Simmonds, I. and Rudeva, I.: The great Arctic cyclone of August 2012, Geophys. Res. Lett., 39, L23709, https://doi.org/10.1029/2012GL054259, 2012. a
Simpson, R. H.: Evolution of the Kona storm a subtropical cyclones, J. Atmos. Sci., 9, 24–35, https://doi.org/10.1175/1520-0469(1952)009<0024:EOTKSA>2.0.CO;2, 1952. a
Sprenger, M., Fragkoulidis, G., Binder, H., Croci-Maspoli, M., Graf, P., Grams, C. M., Knippertz, P., Madonna, E., Schemm, S., Škerlak, B., and Wernli, H.: Global climatologies of Eulerian and Lagrangian flow features based on ERA-Interim, B. Am. Meteorol. Soc., 98, 1739–1748, https://doi.org/10.1175/BAMS-D-15-00299.1, 2017. a, b, c, d
Stoelinga, M. T.: A potential vorticity-based study of the role of diabatic heating and friction in a numerically simulated baroclinic cyclone, Mon. Weather Rev., 124, 849–874, https://doi.org/10.1175/1520-0493(1996)124<0849:APVBSO>2.0.CO;2, 1996. a
Stone, H. L.: Iterative solution of implicit approximations of multidimensional partial differential equations, SIAM J. Numer. Anal., 5, 530–558, 1968. a
Sutcliffe, R. C.: A contribution to the problem of development, Q. J. Roy. Meteor. Soc., 73, 370–383, https://doi.org/10.1002/qj.49707331710, 1947. a
Tamarin, T. and Kaspi, Y.: The poleward motion of extratropical cyclones from a potential vorticity tendency analysis, J. Atmos. Sci., 73, 1687–1707, https://doi.org/10.1175/JAS-D-15-0168.1, 2016. a, b, c, d
Thomas, B. C. and Martin, J. E.: A synoptic climatology and composite analysis of the Alberta Clipper, Weather Forecast., 22, 315–333, https://doi.org/10.1175/WAF982.1, 2007.
a
Trenberth, K. E.: On the interpretation of the diagnostic quasi-geostrophic omega equation, Mon. Weather Rev., 106, 131–137, https://doi.org/10.1175/1520-0493(1978)106<0131:OTIOTD>2.0.CO;2, 1978. a
Ulbrich, U., Pinto, J. G., Kupfer, H., Leckebusch, G., Spangehl, T., and Reyers, M.: Changing Northern Hemisphere storm tracks in an ensemble of IPCC climate change simulations, J. Climate, 21, 1669–1679, https://doi.org/10.1175/2007JCLI1992.1, 2008. 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, https://doi.org/10.1175/JAS3766.1, 2006.
a, b, c, d
Whitaker, J. S. and Davis, C. A.: Cyclogenesis in a saturated environment, J. Atmos. Sci., 51, 889–908, https://doi.org/10.1175/1520-0469(1994)051<0889:CIASE>2.0.CO;2, 1994. a
Zahn, M. and von Storch, H.: A long-term climatology of North Atlantic polar lows, Geophys. Res. Lett., 35, L22702, https://doi.org/10.1029/2008GL035769, 2008. a
Zappa, G., Shaffrey, L. C., and Hodges, K. I.: The ability of CMIP5 models to simulate North Atlantic extratropical cyclones, J. Climate, 26, 5379–5396, https://doi.org/10.1175/JCLI-D-12-00501.1, 2013. a
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.
The strongest cyclone intensification is associated with a strong dry-dynamical forcing....
