Articles | Volume 6, issue 1
https://doi.org/10.5194/wcd-6-211-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/wcd-6-211-2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| Highlight paper
| 
18 Feb 2025
Research article | Highlight paper |
| 18 Feb 2025
| 18 Feb 2025
Synoptic perspective on the conversion and maintenance of local available potential energy in extratropical cyclones
Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
Lukas Papritz
Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
European Centre for Medium-Range Weather Forecasts (ECMWF), Bonn, Germany
Michael Sprenger
Institute for Atmospheric and Climate Science, ETH Zurich, Zurich, Switzerland
Christian M. Grams
Institute of Meteorology and Climate Research – Troposphere Research (IMKTRO), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany
now at: Federal Office of Meteorology and Climatology, MeteoSwiss, Zurich Airport, Switzerland
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Philip Rupp, Jonas Spaeth, Hilla Afargan-Gerstman, Dominik Büeler, Michael Sprenger, and Thomas Birner
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Joshua Dorrington, Marta Wenta, Federico Grazzini, Linus Magnusson, Frederic Vitart, and Christian M. Grams
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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
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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
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Belinda Hotz, Lukas Papritz, and Matthias Röthlisberger
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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
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Weather Clim. Dynam., 5, 181–209, https://doi.org/10.5194/wcd-5-181-2024, https://doi.org/10.5194/wcd-5-181-2024, 2024
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Our study links air–sea interactions over the Gulf Stream to an atmospheric block in February 2019. We found that over 23 % of air masses that were lifted into the block by cyclones interacted with the Gulf Stream. As cyclones pass over the Gulf Stream, they cause intense surface evaporation events, preconditioning the environment for the development of cyclones. This implies that air–sea interactions over the Gulf Stream affect the large-scale dynamics in the North Atlantic–European region.
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
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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.
Julian F. Quinting, Christian M. Grams, Edmund Kar-Man Chang, Stephan Pfahl, and Heini Wernli
Weather Clim. Dynam., 5, 65–85, https://doi.org/10.5194/wcd-5-65-2024, https://doi.org/10.5194/wcd-5-65-2024, 2024
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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
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Despite the general warming trend, wintertime cold-air outbreaks in Europe have remained nearly as extreme and as common as decades ago. In this study, we identify six principal cold anomaly types over Europe in 1979–2020. We show the origins of various physical processes and their contributions to the formation of cold wintertime air masses.
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
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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
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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.
Annika Oertel, Annette K. Miltenberger, Christian M. Grams, and Corinna Hoose
Atmos. Chem. Phys., 23, 8553–8581, https://doi.org/10.5194/acp-23-8553-2023, https://doi.org/10.5194/acp-23-8553-2023, 2023
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Warm conveyor belts (WCBs) are cloud- and precipitation-producing airstreams in extratropical cyclones that are important for the large-scale flow and cloud radiative forcing. We analyze cloud formation processes during WCB ascent in a two-moment microphysics scheme. Quantification of individual diabatic heating rates shows the importance of condensation, vapor deposition, rain evaporation, melting, and cloud-top radiative cooling for total heating and WCB-related potential vorticity structure.
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
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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.
Axel Seifert, Vanessa Bachmann, Florian Filipitsch, Jochen Förstner, Christian M. Grams, Gholam Ali Hoshyaripour, Julian Quinting, Anika Rohde, Heike Vogel, Annette Wagner, and Bernhard Vogel
Atmos. Chem. Phys., 23, 6409–6430, https://doi.org/10.5194/acp-23-6409-2023, https://doi.org/10.5194/acp-23-6409-2023, 2023
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We investigate how mineral dust can lead to the formation of cirrus clouds. Dusty cirrus clouds lead to a reduction in solar radiation at the surface and, hence, a reduced photovoltaic power generation. Current weather prediction systems are not able to predict this interaction between mineral dust and cirrus clouds. We have developed a new physical description of the formation of dusty cirrus clouds. Overall we can show a considerable improvement in the forecast quality of clouds and radiation.
Seraphine Hauser, Franziska Teubler, Michael Riemer, Peter Knippertz, and Christian M. Grams
Weather Clim. Dynam., 4, 399–425, https://doi.org/10.5194/wcd-4-399-2023, https://doi.org/10.5194/wcd-4-399-2023, 2023
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Blocking describes a flow configuration in the midlatitudes where stationary high-pressure systems block the propagation of weather systems. This study combines three individual perspectives that capture the dynamics and importance of various processes in the formation of a major blocking in 2016 from a weather regime perspective. In future work, this framework will enable a holistic view of the dynamics and the role of moist processes in different life cycle stages of blocked weather regimes.
Franziska Teubler, Michael Riemer, Christopher Polster, Christian M. Grams, Seraphine Hauser, and Volkmar Wirth
Weather Clim. Dynam., 4, 265–285, https://doi.org/10.5194/wcd-4-265-2023, https://doi.org/10.5194/wcd-4-265-2023, 2023
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Weather regimes govern an important part of the sub-seasonal variability of the mid-latitude circulation. The year-round dynamics of blocked regimes in the Atlantic European region are investigated in over 40 years of data. We show that the dynamics between the regimes are on average very similar. Within the regimes, the main variability – starting from the characteristics of dynamical processes alone – dominates and transcends the variability in season and types of transitions.
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
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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
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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
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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
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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
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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
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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
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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
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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
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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.
Katharina Hartmuth, Maxi Boettcher, Heini Wernli, and Lukas Papritz
Weather Clim. Dynam., 3, 89–111, https://doi.org/10.5194/wcd-3-89-2022, https://doi.org/10.5194/wcd-3-89-2022, 2022
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In this study, we introduce a novel method to objectively define and identify extreme Arctic seasons based on different surface variables. We find that such seasons are resulting from various combinations of unusual seasonal conditions. The occurrence or absence of different atmospheric processes strongly affects the character of extreme Arctic seasons. Further, changes in sea ice and sea surface temperature can strongly influence the formation of such a season in distinct regions.
Julian F. Quinting, Christian M. Grams, Annika Oertel, and Moritz Pickl
Geosci. Model Dev., 15, 731–744, https://doi.org/10.5194/gmd-15-731-2022, https://doi.org/10.5194/gmd-15-731-2022, 2022
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This study applies novel artificial-intelligence-based models that allow the identification of one specific weather system which affects the midlatitude circulation. We show that the models yield similar results as their trajectory-based counterpart, which requires data at higher spatiotemporal resolution and is computationally more expensive. Overall, we aim to show how deep learning methods can be used efficiently to support process understanding of biases in weather prediction models.
Julian F. Quinting and Christian M. Grams
Geosci. Model Dev., 15, 715–730, https://doi.org/10.5194/gmd-15-715-2022, https://doi.org/10.5194/gmd-15-715-2022, 2022
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Physical processes in weather systems importantly affect the midlatitude large-scale circulation. This study introduces an artificial-intelligence-based framework which allows the identification of an important weather system – the so-called warm conveyor belt (WCB) – at comparably low computational costs and from data at low spatial and temporal resolution. The framework thus newly enables the systematic investigation of WCBs in large data sets such as climate model projections.
Sonja Murto, Rodrigo Caballero, Gunilla Svensson, and Lukas Papritz
Weather Clim. Dynam., 3, 21–44, https://doi.org/10.5194/wcd-3-21-2022, https://doi.org/10.5194/wcd-3-21-2022, 2022
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This study uses reanalysis data to investigate the role of atmospheric blocking, prevailing high-pressure systems and mid-latitude cyclones in driving high-Arctic wintertime warm extreme events. These events are mainly preceded by Ural and Scandinavian blocks, which are shown to be significantly influenced and amplified by cyclones in the North Atlantic. It also highlights processes that need to be well captured in climate models for improving their representation of Arctic wintertime climate.
Lukas Papritz, David Hauswirth, and Katharina Hartmuth
Weather Clim. Dynam., 3, 1–20, https://doi.org/10.5194/wcd-3-1-2022, https://doi.org/10.5194/wcd-3-1-2022, 2022
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Water vapor profoundly impacts the Arctic, for example by contributing to sea ice melt. A substantial portion of water vapor in the Arctic originates at mid-latitudes and is transported poleward in a few episodic and intense events. This transport is accomplished by low- and high-pressure systems occurring in specific regions or following particular tracks. Here, we explore how the type of weather system impacts where the water vapor is coming from and how it is transported poleward.
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
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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.
Cited articles
Ambaum, M. H. P. and Novak, L.: A nonlinear oscillator describing storm track variability, Q. J. Roy. Meteor. Soc., 140, 2680–2684, https://doi.org/10.1002/qj.2352, 2014. a, b
Andrews, D. G.: A note on potential energy density in a stratified compressible fluid, J. Fluid Mech., 107, 227–236, https://doi.org/10.1017/S0022112081001754, 1981. 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
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, b
Bosart, L. F., Hakim, G. J., Tyle, K. R., Bedrick, M. A., Bracken, W. E., Dickinson, M. J., and Schultz, D. M.: Large-scale antecedent conditions associated with the 12–14 March 1993 cyclone (“Superstorm '93”) over eastern North America, Mon. Weather Rev., 124, 1865–1891, https://doi.org/10.1175/1520-0493(1996)124<1865:LSACAW>2.0.CO;2, 1996. a
Bowley, K. A., Gyakum, J. R., and Atallah, E. H.: The role of dynamic tropopause Rossby wave breaking for synoptic-scale buildups in Northern Hemisphere zonal available potential energy, Mon. Weather Rev., 147, 433–455, https://doi.org/10.1175/MWR-D-18-0143.1, 2019. a, b
Brayshaw, D. J., Hoskins, B., and Blackburn, M.: The basic ingredients of the North Atlantic storm track. Part I: Land–sea contrast and orography, J. Atmos. Sci., 66, 2539–2558, https://doi.org/10.1175/2009JAS3078.1, 2009. a
Brayshaw, D. J., Hoskins, B., and Blackburn, M.: The basic ingredients of the North Atlantic storm track. Part II: Sea surface temperatures, J. Atmos. Sci., 68, 1784–1805, https://doi.org/10.1175/2011JAS3674.1, 2011. a
Browning, K. A. and Roberts, N. M.: Structure of a frontal cyclone, Q. J. Roy. Meteor. Soc., 120, 1535–1557, https://doi.org/10.1002/qj.49712052006, 1994. a
Charney, J. G.: The dynamics of long waves in a baroclinic westerly current, J. Atmos. Sci., 4, 136–162, https://doi.org/10.1175/1520-0469(1947)004<0136:TDOLWI>2.0.CO;2, 1947. a
Czaja, A., Frankignoul, C., Minobe, S., and Vannière, B.: Simulating the midlatitude atmospheric circulation: What might we gain from high-resolution modeling of air-sea interactions?, Current Climate Change Reports, 5, 390–406, https://doi.org/10.1007/s40641-019-00148-5, 2019. 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
Davis, C. A. and Emanuel, K. A.: Potential vorticity diagnostics of cyclogenesis, Mon. Weather Rev., 119, 1929–1953, https://doi.org/10.1175/1520-0493(1991)119<1929:PVDOC>2.0.CO;2, 1991. a
Eady, E. T.: Long waves and cyclone waves, Tellus, 1, 33–52, https://doi.org/10.3402/tellusa.v1i3.8507, 1949. a, b, c, d
Gertler, C. G. and O'Gorman, P. A.: Changing available energy for extratropical cyclones and associated convection in Northern Hemisphere summer, P. Natl. Acad. Sci. USA, 116, 4105–4110, https://doi.org/10.1073/pnas.1812312116, 2019. a
Gertler, C. G., O'Gorman, P. A., and Pfahl, S.: Moist available potential energy of the mean state of the atmosphere and the thermodynamic potential for warm conveyor belts and convection, Weather Clim. Dynam., 4, 361–379, https://doi.org/10.5194/wcd-4-361-2023, 2023. a, b
Grams, C. M., Beerli, R., Pfenninger, S., Staffell, I., and Wernli, H.: Balancing Europe's wind-power output through spatial deployment informed by weather regimes, Nat. Clim. Change, 7, 557–562, https://doi.org/10.1038/nclimate3338, 2017. 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
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 single levels from 1940 to present, Copernicus Climate Change Service (C3S) Climate Data Store (CDS) [data set], https://doi.org/10.24381/cds.adbb2d47, 2023. a
Holliday, D. and McIntyre, M. E.: On potential energy density in an incompressible, stratified fluid, J. Fluid Mech., 107, 221–225, https://doi.org/10.1017/S0022112081001742, 1981. a
Hoskins, B., Pedder, M., and Jones, D. W.: The omega equation and potential vorticity, Q. J. Roy. Meteor. Soc., 129, 3277–3303, https://doi.org/10.1256/qj.02.135, 2003. a
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
Hotta, D. and Nakamura, H.: On the significance of the sensible heat supply from the ocean in the maintenance of the mean baroclinicity along storm tracks, J. Climate, 24, 3377–3401, https://doi.org/10.1175/2010JCLI3910.1, 2011. a, b
Johnson, D. R.: The available potential energy of storms, J. Atmos. Sci., 27, 727–741, https://doi.org/10.1175/1520-0469(1970)027<0727:TAPEOS>2.0.CO;2, 1970. a
Keyser, D. and Shapiro, M. A.: A Review of the Structure and Dynamics of Upper-Level Frontal Zones, Mon. Weather Rev., 114, 452–499, https://doi.org/10.1175/1520-0493(1986)114<0452:AROTSA>2.0.CO;2, 1986. a
Koch, P., Wernli, H., and Davies, H. C.: An event-based jet-stream climatology and typology, Int. J. Climatol., 26, 283–301, https://doi.org/10.1002/joc.1255, 2006. a, b
Kwon, Y.-O., Alexander, M. A., Bond, N. A., Frankignoul, C., Nakamura, H., Qiu, B., and Thompson, L. A.: Role of the Gulf Stream and Kuroshio–Oyashio systems in large-scale atmosphere–ocean interaction: A review, J. Climate, 23, 3249–3281, https://doi.org/10.1175/2010JCLI3343.1, 2010. a
Leach, N. J., Weisheimer, A., Allen, M. R., and Palmer, T.: Forecast-based attribution of a winter heatwave within the limit of predictability, P. Natl. Acad. Sci. USA, 118, e2112087118, https://doi.org/10.1073/pnas.2112087118, 2021. a
Li, Z. and O'Gorman, P. A.: Response of vertical velocities in extratropical precipitation extremes to climate Change, J. Climate, 33, 7125–7139, https://doi.org/10.1175/JCLI-D-19-0766.1, 2020. a
Lorenz, E. N.: Available potential energy and the maintenance of the general circulation, Tellus, 7, 157–167, https://doi.org/10.3402/tellusa.v7i2.8796, 1955. a, b, c
Lorenz, E. N.: Numerical evaluation of moist available energy, Tellus, 31, 230–235, https://doi.org/10.1111/j.2153-3490.1979.tb00901.x, 1979. a
Marcheggiani, A. and Ambaum, M. H. P.: The role of heat-flux–temperature covariance in the evolution of weather systems, Weather Clim. Dynam., 1, 701–713, https://doi.org/10.5194/wcd-1-701-2020, 2020. a, b
Margules, M.: Über die Energie der Stürme, Jahrbücher der k.k. Zentralanstalt für Meteorologie und Erdmagnetismus, Kaiserlich-Königliche Hof- und Staatsdruckerei, 1903. a
Mathews, J. and Czaja, A.: Oceanic maintenance of atmospheric blocking in wintertime in the North Atlantic, Clim. Dyn., 62, 6159–6172, https://doi.org/10.1007/s00382-024-07196-0, 2024. a
Molteni, F., King, M. P., Kucharski, F., and Straus, D. M.: Planetary-scale variability in the northern winter and the impact of land–sea thermal contrast, Clim. Dyn., 37, 151–170, https://doi.org/10.1007/s00382-010-0906-z, 2011. a
Nakamura, H., Sampe, T., Goto, A., Ohfuchi, W., and Xie, S.-P.: On the importance of midlatitude oceanic frontal zones for the mean state and dominant variability in the tropospheric circulation, Geophys. Res. Lett., 35, L15709, https://doi.org/10.1029/2008GL034010, 2008. a
Nie, J. and Sobel, A. H.: Modeling the interaction between quasigeostrophic vertical motion and convection in a single column, J. Atmos. Sci., 73, 1101–1117, https://doi.org/10.1175/JAS-D-15-0205.1, 2016. a
Novak, L., Ambaum, M., and Tailleux, R.: Marginal stability and predator–prey behaviour within storm tracks, Q. J. Roy. Meteor. Soc., 143, 1421–1433, https://doi.org/10.1002/qj.3014, 2017. a, b
Omrani, N.-E., Ogawa, F., Nakamura, H., Keenlyside, N., Lubis, S. W., and Matthes, K.: Key role of the ocean western boundary currents in shaping the Northern Hemisphere climate, Sci. Rep.-UK, 9, 3014, https://doi.org/10.1038/s41598-019-39392-y, 2019. a
Oort, A. H.: On estimates of the atmopsheric energy cycle, Mon. Weather Rev., 92, 483–493, https://doi.org/10.1175/1520-0493(1964)092<0483:OEOTAE>2.3.CO;2, 1964. a, b
Papritz, L. and Spengler, T.: Analysis of the slope of isentropic surfaces and its tendencies over the North Atlantic, Q. J. Roy. Meteor. Soc., 141, 3226–3238, https://doi.org/10.1002/qj.2605, 2015. a, b
Papritz, L., Pfahl, S., Sodemann, H., and Wernli, H.: A climatology of cold air outbreaks and their impact on air–sea heat fluxes in the high-latitude South Pacific, J. Climate, 28, 342–364, https://doi.org/10.1175/JCLI-D-14-00482.1, 2015. a, b
Peixóto, J. P. and Oort, A. H.: The annual distribution of atmospheric energy on a planetary scale, J. Geophys. Res., 79, 2149–2159, https://doi.org/10.1029/JC079i015p02149, 1974. a, b, c
Pfahl, S., Madonna, E., Boettcher, M., Joos, H., and Wernli, H.: Warm conveyor belts in the ERA-Interim dataset (1979–2010). Part II: Moisture origin and relevance for precipitation, J. Climate, 27, 27–40, https://doi.org/10.1175/JCLI-D-13-00223.1, 2014. a
Portal, A., Pasquero, C., D'Andrea, F., Davini, P., Hamouda, M. E., and Rivière, G.: Influence of reduced winter land–sea contrast on the midlatitude atmospheric circulation, J. Climate, 35, 6237–6251, https://doi.org/10.1175/JCLI-D-21-0941.1, 2022. a
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
Shapiro, M. A. and Keyser, D.: Fronts, jet streams and the tropopause, American Meteorological Society, Boston, MA, 167–191, https://doi.org/10.1007/978-1-944970-33-8_10, 1990. a
Shepherd, T. G.: A unified theory of available potential energy, Atmos.-Ocean, 31, 1–26, https://doi.org/10.1080/07055900.1993.9649460, 1993. a
Smith, P. J.: On the contribution of a limited region to the global energy budget, Tellus, 21, 202–207, https://doi.org/10.1111/j.2153-3490.1969.tb00432.x, 1969. a
Smith, P. J.: The energetics of extratropical cyclones, Rev. Geophys., 18, 378–386, https://doi.org/10.1029/RG018i002p00378, 1980. a
Sprenger, M. and Wernli, H.: The LAGRANTO Lagrangian analysis tool – version 2.0, Geosci. Model Dev., 8, 2569–2586, https://doi.org/10.5194/gmd-8-2569-2015, 2015. 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
Swanson, K. L. and Pierrehumbert, R. T.: Lower-tropospheric heat transport in the Pacific storm track, J. Atmos. Sci., 54, 1533–1543, https://doi.org/10.1175/1520-0469(1997)054<1533:LTHTIT>2.0.CO;2, 1997. a, b
Tailleux, R.: Available potential energy and exergy in stratified fluids, Annu. Rev. Fluid Mech., 45, 35–58, https://doi.org/10.1146/annurev-fluid-011212-140620, 2013. a
Tailleux, R.: Local available energetics of multicomponent compressible stratified fluids, J. Fluid Mech., 842, R1, https://doi.org/10.1017/jfm.2018.196, 2018. a
Wernli, H. and Davies, H. C.: A Lagrangian-based analysis of extratropical cyclones. I: The method and some applications, Q. J. Roy. Meteor. Soc., 123, 467–489, https://doi.org/10.1002/qj.49712353811, 1997. 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
Wintels, W. and Gyakum, J. R.: Synoptic climatology of Northern Hemisphere available potential energy collapses, Tellus A, 52, 347–364, https://doi.org/10.3402/tellusa.v52i4.12273, 2000. a
Yamamoto, A., Nonaka, M., Martineau, P., Yamazaki, A., Kwon, Y.-O., Nakamura, H., and Taguchi, B.: Oceanic moisture sources contributing to wintertime Euro-Atlantic blocking, Weather Clim. Dynam., 2, 819–840, https://doi.org/10.5194/wcd-2-819-2021, 2021. a
Young, M. and Galvin, J.: The record-breaking warm spell of February 2019 in Britain, the Channel Islands, France and the Netherlands, Weather, 75, 36–45, https://doi.org/10.1002/wea.3664, 2020. a
Editorial statement
This study provides a novel Lagrangian perspective on cyclogenesis grounded in atmospheric energetics. While the energetics framework is commonly used to understand the planetary scale circulation, its application to synoptic scales is less explored. The authors establish a close connection between extratropical baroclinic zones and local available potential energy, and further analyze air parcel trajectories to link conversions between potential and kinetic energy to specific features of the developing cyclones. The results of this study offer insights into the local, synoptic and large scale contributions to cyclogenesis that are relevant for diverse disciplines in atmospheric and climate sciences.
This study provides a novel Lagrangian perspective on cyclogenesis grounded in atmospheric...
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.
Although extratropical cyclones in the North Atlantic are among the most impactful midlatitude...
