Articles | Volume 2, issue 1
https://doi.org/10.5194/wcd-2-255-2021
© 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-2-255-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
29 Mar 2021
Research article |
| 29 Mar 2021
| 29 Mar 2021
A process-based anatomy of Mediterranean cyclones: from baroclinic lows to tropical-like systems
Emmanouil Flaounas
CORRESPONDING AUTHOR
Institute for Atmospheric and Climate Science, ETH Zurich, Zurich,
Switzerland
Suzanne L. Gray
Department of Meteorology, University of Reading, Reading, UK
Franziska Teubler
Institute for Atmospheric Physics, Johannes Gutenberg-Universität Mainz, Mainz, Germany
Related authors
Kerry Emanuel, Tommaso Alberti, Stella Bourdin, Suzana J. Camargo, Davide Faranda, Emmanouil Flaounas, Juan Jesus Gonzalez-Aleman, Chia-Ying Lee, Mario Marcello Miglietta, Claudia Pasquero, Alice Portal, Hamish Ramsay, Marco Reale, and Romualdo Romero
Weather Clim. Dynam., 6, 901–926, https://doi.org/10.5194/wcd-6-901-2025, https://doi.org/10.5194/wcd-6-901-2025, 2025
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Storms strongly resembling hurricanes are sometimes observed to form well outside the tropics, even in polar latitudes. They behave capriciously, developing very rapidly and then dying just as quickly. We show that strong dynamical processes in the atmosphere can sometimes cause it to become much colder locally than the underlying ocean, creating the conditions for hurricanes to form but only over small areas and for short times. We call the resulting storms "CYCLOPs".
Marco Chericoni, Giorgia Fosser, Emmanouil Flaounas, Gianmaria Sannino, and Alessandro Anav
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This study explores how sea surface energy influences both the atmosphere and ocean at various vertical levels during extreme Mediterranean cyclones. It focuses on cyclones' precipitation and wind speed response, as well as on ocean temperature variation. The findings highlight the regional coupled model's ability to coherently represent the thermodynamic and dynamic processes of the cyclones across both the atmosphere and the ocean.
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
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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.
Alexander Scherrmann, Heini Wernli, and Emmanouil Flaounas
Weather Clim. Dynam., 5, 419–438, https://doi.org/10.5194/wcd-5-419-2024, https://doi.org/10.5194/wcd-5-419-2024, 2024
Short summary
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We show that the formation of Mediterranean cyclones follows the presence of cyclones over the North Atlantic. The distinct regions of cyclone activity in the Mediterranean in the different seasons can be linked to the atmospheric state, in particular the position of the polar jet over the North Atlantic. With this we now better understand the processes that lead to the formation of Mediterranean cyclones. We used a novel simulation framework in which we directly show and probe this connection.
Dimitra Denaxa, Gerasimos Korres, Emmanouil Flaounas, and Maria Hatzaki
Ocean Sci., 20, 433–461, https://doi.org/10.5194/os-20-433-2024, https://doi.org/10.5194/os-20-433-2024, 2024
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This study explores extreme marine summers (EMSs) in the Mediterranean Sea using sea surface temperature (SST) data. EMSs arise mainly due to the warmest summer days being unusually warm. Air–sea heat fluxes drive EMSs in northern regions, where also enhanced marine heatwave conditions are found during EMSs. Long-term SST changes lead to warmer EMSs while not affecting the way daily SST values are organized during EMSs. Findings enhance comprehension of anomalously warm conditions in the basin.
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.
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
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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.
Christian Ferrarin, Florian Pantillon, Silvio Davolio, Marco Bajo, Mario Marcello Miglietta, Elenio Avolio, Diego S. Carrió, Ioannis Pytharoulis, Claudio Sanchez, Platon Patlakas, Juan Jesús González-Alemán, and Emmanouil Flaounas
Nat. Hazards Earth Syst. Sci., 23, 2273–2287, https://doi.org/10.5194/nhess-23-2273-2023, https://doi.org/10.5194/nhess-23-2273-2023, 2023
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The combined use of meteorological and ocean models enabled the analysis of extreme sea conditions driven by Medicane Ianos, which hit the western coast of Greece on 18 September 2020, flooding and damaging the coast. The large spread associated with the ensemble highlighted the high model uncertainty in simulating such an extreme weather event. The different simulations have been used for outlining hazard scenarios that represent a fundamental component of the coastal risk assessment.
Alexander Scherrmann, Heini Wernli, and Emmanouil Flaounas
Weather Clim. Dynam., 4, 157–173, https://doi.org/10.5194/wcd-4-157-2023, https://doi.org/10.5194/wcd-4-157-2023, 2023
Short summary
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We investigate the dynamical origin of the lower-atmospheric potential vorticity (PV; linked to the intensity of cyclones) in Mediterranean cyclones. We quantify the contribution of the cyclone and the environment by tracing PV backward in time and space and linking it to the track of the cyclone. We find that the lower-tropospheric PV is produced shortly before the cyclone's stage of highest intensity. We investigate the driving processes and use a global dataset and a process-resolving one.
Emmanouil Flaounas, Silvio Davolio, Shira Raveh-Rubin, Florian Pantillon, Mario Marcello Miglietta, Miguel Angel Gaertner, Maria Hatzaki, Victor Homar, Samira Khodayar, Gerasimos Korres, Vassiliki Kotroni, Jonilda Kushta, Marco Reale, and Didier Ricard
Weather Clim. Dynam., 3, 173–208, https://doi.org/10.5194/wcd-3-173-2022, https://doi.org/10.5194/wcd-3-173-2022, 2022
Short summary
Short summary
This is a collective effort to describe the state of the art in Mediterranean cyclone dynamics, climatology, prediction (weather and climate scales) and impacts. More than that, the paper focuses on the future directions of research that would advance the broader field of Mediterranean cyclones as a whole. Thereby, we propose interdisciplinary cooperation and additional modelling and forecasting strategies, and we highlight the need for new impact-oriented approaches to climate prediction.
Samira Khodayar, Silvio Davolio, Paolo Di Girolamo, Cindy Lebeaupin Brossier, Emmanouil Flaounas, Nadia Fourrie, Keun-Ok Lee, Didier Ricard, Benoit Vie, Francois Bouttier, Alberto Caldas-Alvarez, and Veronique Ducrocq
Atmos. Chem. Phys., 21, 17051–17078, https://doi.org/10.5194/acp-21-17051-2021, https://doi.org/10.5194/acp-21-17051-2021, 2021
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Heavy precipitation (HP) constitutes a major meteorological threat in the western Mediterranean. Every year, recurrent events affect the area with fatal consequences. Despite this being a well-known issue, open questions still remain. The understanding of the underlying mechanisms and the modeling representation of the events must be improved. In this article we present the most recent lessons learned from the Hydrological Cycle in the Mediterranean Experiment (HyMeX).
Emmanouil Flaounas, Matthias Röthlisberger, Maxi Boettcher, Michael Sprenger, and Heini Wernli
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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.
Kerry Emanuel, Tommaso Alberti, Stella Bourdin, Suzana J. Camargo, Davide Faranda, Emmanouil Flaounas, Juan Jesus Gonzalez-Aleman, Chia-Ying Lee, Mario Marcello Miglietta, Claudia Pasquero, Alice Portal, Hamish Ramsay, Marco Reale, and Romualdo Romero
Weather Clim. Dynam., 6, 901–926, https://doi.org/10.5194/wcd-6-901-2025, https://doi.org/10.5194/wcd-6-901-2025, 2025
Short summary
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Storms strongly resembling hurricanes are sometimes observed to form well outside the tropics, even in polar latitudes. They behave capriciously, developing very rapidly and then dying just as quickly. We show that strong dynamical processes in the atmosphere can sometimes cause it to become much colder locally than the underlying ocean, creating the conditions for hurricanes to form but only over small areas and for short times. We call the resulting storms "CYCLOPs".
Marco Chericoni, Giorgia Fosser, Emmanouil Flaounas, Gianmaria Sannino, and Alessandro Anav
Weather Clim. Dynam., 6, 627–643, https://doi.org/10.5194/wcd-6-627-2025, https://doi.org/10.5194/wcd-6-627-2025, 2025
Short summary
Short summary
This study explores how sea surface energy influences both the atmosphere and ocean at various vertical levels during extreme Mediterranean cyclones. It focuses on cyclones' precipitation and wind speed response, as well as on ocean temperature variation. The findings highlight the regional coupled model's ability to coherently represent the thermodynamic and dynamic processes of the cyclones across both the atmosphere and the ocean.
Suzanne L. Gray, Ambrogio Volonté, Oscar Martínez-Alvarado, and Ben J. Harvey
Weather Clim. Dynam., 5, 1523–1544, https://doi.org/10.5194/wcd-5-1523-2024, https://doi.org/10.5194/wcd-5-1523-2024, 2024
Short summary
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Sting jets occur in some of the most damaging cyclones impacting Europe. We present the first climatology of sting-jet cyclones over the major ocean basins. Cyclones with sting-jet precursors occur over the North Atlantic, North Pacific, and Southern Oceans, with implications for wind warnings. Precursor cyclones have distinct characteristics, even in reanalyses that are too coarse to fully resolve sting jets, evidencing the climatological consequences of strong diabatic cloud processes.
Claudio Sánchez, Suzanne Gray, Ambrogio Volonté, Florian Pantillon, Ségolène Berthou, and Silvio Davolio
Weather Clim. Dynam., 5, 1429–1455, https://doi.org/10.5194/wcd-5-1429-2024, https://doi.org/10.5194/wcd-5-1429-2024, 2024
Short summary
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Medicane Ianos was a very intense cyclone that led to harmful impacts over Greece. We explore what processes are important for the forecasting of Medicane Ianos, with the use of the Met Office weather model. There was a preceding precipitation event before Ianos’s birth, whose energetics generated a bubble in the tropopause. This bubble created the necessary conditions for Ianos to emerge and strengthen, and the processes are enhanced in simulations with a warmer Mediterranean Sea.
Heini Wernli and Suzanne L. Gray
Weather Clim. Dynam., 5, 1299–1408, https://doi.org/10.5194/wcd-5-1299-2024, https://doi.org/10.5194/wcd-5-1299-2024, 2024
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The science of extratropical dynamics has reached a new level where the interplay of dry dynamics with effects of latent heating in clouds and other diabatic processes is considered central to the field. This review documents how research about the role of diabatic processes evolved over more than a century; it highlights that progress relied essentially on the integration of theory, field campaigns, novel diagnostics, and numerical modelling, and it outlines avenues for future research.
Florian Pantillon, Silvio Davolio, Elenio Avolio, Carlos Calvo-Sancho, Diego Saul Carrió, Stavros Dafis, Emanuele Silvio Gentile, Juan Jesus Gonzalez-Aleman, Suzanne Gray, Mario Marcello Miglietta, Platon Patlakas, Ioannis Pytharoulis, Didier Ricard, Antonio Ricchi, Claudio Sanchez, and Emmanouil Flaounas
Weather Clim. Dynam., 5, 1187–1205, https://doi.org/10.5194/wcd-5-1187-2024, https://doi.org/10.5194/wcd-5-1187-2024, 2024
Short summary
Short summary
Cyclone Ianos of September 2020 was a high-impact but poorly predicted medicane (Mediterranean hurricane). A community effort of numerical modelling provides robust results to improve prediction. It is found that the representation of local thunderstorms controlled the interaction of Ianos with a jet stream at larger scales and its subsequent evolution. The results help us understand the peculiar dynamics of medicanes and provide guidance for the next generation of weather and climate models.
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.
Seraphine Hauser, Franziska Teubler, Michael Riemer, Peter Knippertz, and Christian M. Grams
Weather Clim. Dynam., 5, 633–658, https://doi.org/10.5194/wcd-5-633-2024, https://doi.org/10.5194/wcd-5-633-2024, 2024
Short summary
Short summary
Blocking over Greenland has substantial impacts on the weather and climate in mid- and high latitudes. This study applies a quasi-Lagrangian thinking on the dynamics of Greenland blocking and reveals two pathways of anticyclonic anomalies linked to the block. Moist processes were found to play a dominant role in the formation and maintenance of blocking. This emphasizes the necessity of the correct representation of moist processes in weather and climate models to realistically depict blocking.
Alexander Scherrmann, Heini Wernli, and Emmanouil Flaounas
Weather Clim. Dynam., 5, 419–438, https://doi.org/10.5194/wcd-5-419-2024, https://doi.org/10.5194/wcd-5-419-2024, 2024
Short summary
Short summary
We show that the formation of Mediterranean cyclones follows the presence of cyclones over the North Atlantic. The distinct regions of cyclone activity in the Mediterranean in the different seasons can be linked to the atmospheric state, in particular the position of the polar jet over the North Atlantic. With this we now better understand the processes that lead to the formation of Mediterranean cyclones. We used a novel simulation framework in which we directly show and probe this connection.
Dimitra Denaxa, Gerasimos Korres, Emmanouil Flaounas, and Maria Hatzaki
Ocean Sci., 20, 433–461, https://doi.org/10.5194/os-20-433-2024, https://doi.org/10.5194/os-20-433-2024, 2024
Short summary
Short summary
This study explores extreme marine summers (EMSs) in the Mediterranean Sea using sea surface temperature (SST) data. EMSs arise mainly due to the warmest summer days being unusually warm. Air–sea heat fluxes drive EMSs in northern regions, where also enhanced marine heatwave conditions are found during EMSs. Long-term SST changes lead to warmer EMSs while not affecting the way daily SST values are organized during EMSs. Findings enhance comprehension of anomalously warm conditions in the basin.
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.
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.
Christian Ferrarin, Florian Pantillon, Silvio Davolio, Marco Bajo, Mario Marcello Miglietta, Elenio Avolio, Diego S. Carrió, Ioannis Pytharoulis, Claudio Sanchez, Platon Patlakas, Juan Jesús González-Alemán, and Emmanouil Flaounas
Nat. Hazards Earth Syst. Sci., 23, 2273–2287, https://doi.org/10.5194/nhess-23-2273-2023, https://doi.org/10.5194/nhess-23-2273-2023, 2023
Short summary
Short summary
The combined use of meteorological and ocean models enabled the analysis of extreme sea conditions driven by Medicane Ianos, which hit the western coast of Greece on 18 September 2020, flooding and damaging the coast. The large spread associated with the ensemble highlighted the high model uncertainty in simulating such an extreme weather event. The different simulations have been used for outlining hazard scenarios that represent a fundamental component of the coastal risk assessment.
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
Short summary
Short summary
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.
Ed Hawkins, Philip Brohan, Samantha N. Burgess, Stephen Burt, Gilbert P. Compo, Suzanne L. Gray, Ivan D. Haigh, Hans Hersbach, Kiki Kuijjer, Oscar Martínez-Alvarado, Chesley McColl, Andrew P. Schurer, Laura Slivinski, and Joanne Williams
Nat. Hazards Earth Syst. Sci., 23, 1465–1482, https://doi.org/10.5194/nhess-23-1465-2023, https://doi.org/10.5194/nhess-23-1465-2023, 2023
Short summary
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We examine a severe windstorm that occurred in February 1903 and caused significant damage in the UK and Ireland. Using newly digitized weather observations from the time of the storm, combined with a modern weather forecast model, allows us to determine why this storm caused so much damage. We demonstrate that the event is one of the most severe windstorms to affect this region since detailed records began. The approach establishes a new tool to improve assessments of risk from extreme weather.
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
Short summary
Short summary
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.
Alexander Scherrmann, Heini Wernli, and Emmanouil Flaounas
Weather Clim. Dynam., 4, 157–173, https://doi.org/10.5194/wcd-4-157-2023, https://doi.org/10.5194/wcd-4-157-2023, 2023
Short summary
Short summary
We investigate the dynamical origin of the lower-atmospheric potential vorticity (PV; linked to the intensity of cyclones) in Mediterranean cyclones. We quantify the contribution of the cyclone and the environment by tracing PV backward in time and space and linking it to the track of the cyclone. We find that the lower-tropospheric PV is produced shortly before the cyclone's stage of highest intensity. We investigate the driving processes and use a global dataset and a process-resolving one.
Edgar Dolores-Tesillos, Franziska Teubler, and Stephan Pfahl
Weather Clim. Dynam., 3, 429–448, https://doi.org/10.5194/wcd-3-429-2022, https://doi.org/10.5194/wcd-3-429-2022, 2022
Short summary
Short summary
Strong winds caused by extratropical cyclones represent a costly hazard for European countries. Here, based on CESM-LENS coupled climate simulations, we show that future changes of such strong winds are characterized by an increased magnitude and extended footprint southeast of the cyclone center. This intensification is related to a combination of increased diabatic heating and changes in upper-level wave dynamics.
Emmanouil Flaounas, Silvio Davolio, Shira Raveh-Rubin, Florian Pantillon, Mario Marcello Miglietta, Miguel Angel Gaertner, Maria Hatzaki, Victor Homar, Samira Khodayar, Gerasimos Korres, Vassiliki Kotroni, Jonilda Kushta, Marco Reale, and Didier Ricard
Weather Clim. Dynam., 3, 173–208, https://doi.org/10.5194/wcd-3-173-2022, https://doi.org/10.5194/wcd-3-173-2022, 2022
Short summary
Short summary
This is a collective effort to describe the state of the art in Mediterranean cyclone dynamics, climatology, prediction (weather and climate scales) and impacts. More than that, the paper focuses on the future directions of research that would advance the broader field of Mediterranean cyclones as a whole. Thereby, we propose interdisciplinary cooperation and additional modelling and forecasting strategies, and we highlight the need for new impact-oriented approaches to climate prediction.
Suzanne L. Gray, Kevin I. Hodges, Jonathan L. Vautrey, and John Methven
Weather Clim. Dynam., 2, 1303–1324, https://doi.org/10.5194/wcd-2-1303-2021, https://doi.org/10.5194/wcd-2-1303-2021, 2021
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This research demonstrates, using feature identification and tracking, that anticlockwise rotating vortices at about 7 km altitude called tropopause polar vortices frequently interact with storms developing in the Arctic region, affecting their structure and where they occur. This interaction has implications for the predictability of Arctic weather, given the long lifetime but a relatively small spatial scale of these vortices compared with the density of the polar observation network.
Samira Khodayar, Silvio Davolio, Paolo Di Girolamo, Cindy Lebeaupin Brossier, Emmanouil Flaounas, Nadia Fourrie, Keun-Ok Lee, Didier Ricard, Benoit Vie, Francois Bouttier, Alberto Caldas-Alvarez, and Veronique Ducrocq
Atmos. Chem. Phys., 21, 17051–17078, https://doi.org/10.5194/acp-21-17051-2021, https://doi.org/10.5194/acp-21-17051-2021, 2021
Short summary
Short summary
Heavy precipitation (HP) constitutes a major meteorological threat in the western Mediterranean. Every year, recurrent events affect the area with fatal consequences. Despite this being a well-known issue, open questions still remain. The understanding of the underlying mechanisms and the modeling representation of the events must be improved. In this article we present the most recent lessons learned from the Hydrological Cycle in the Mediterranean Experiment (HyMeX).
Franziska Teubler and Michael Riemer
Weather Clim. Dynam., 2, 535–559, https://doi.org/10.5194/wcd-2-535-2021, https://doi.org/10.5194/wcd-2-535-2021, 2021
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Rossby wave packets impact all aspects of midlatitude weather systems, from their climatological distribution to predictability. Case studies suggest an important role of latent heat release in clouds. We investigate thousands of wave packets with a novel diagnostic. We demonstrate that, on average, the impact of moist processes is substantially different between troughs and ridges and that dry conceptual models of wave packet dynamics should be extended.
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
Adamson, D. S., Belcher, S. E., Hoskins, B. J., and Plant, R. S.:
Boundary-layer friction in midlatitude cyclones, Q. J. Roy. Meteorol. Soc.,
132, 101–124, https://doi.org/10.1256/qj.04.145, 2006.
Aebischer, U. and Schär, C.: Low-Level Potential Vorticity and
Cyclogenesis to the Lee of the Alps, J. Atmos. Sci., 55, 186–207,
https://doi.org/10.1175/1520-0469(1998)055<0186:LLPVAC>2.0.CO;2, 1998.
Ahmadi-Givi, F., Graig, G. C., and Plant, R. S.: The dynamics of a midlatitude cyclone with very strong latent-heat release, Q. J. Roy. Meteorol. Soc., 130, 295–323, https://doi.org/10.1256/qj.02.226, 2004.
Alpert, P., Neeman, B. U., and Shay-El, Y.: Climatological analysis of
Mediterranean cyclones using ECMWF data, Tellus A, 42, 65–77,
https://doi.org/10.3402/tellusa.v42i1.11860, 1990.
Attinger, R., Spreitzer, E., Boettcher, M., Forbes, R., Wernli, H., and Joos,
H.: Quantifying the role of individual diabatic processes for the formation
of PV anomalies in a North Pacific cyclone, Q. J. Roy. Meteorol. Soc., 145,
2454–2476, https://doi.org/10.1002/qj.3573, 2019.
Bleck, R. and Mattocks, C.: A preliminary analysis of the role of potential
vorticity in Alpine lee cyclogenesis, Beitr. Phys. Atmos., 57, 357–368, 1984.
Boettcher, M. and Wernli, H.: Life Cycle Study of a Diabatic Rossby Wave as a Precursor to Rapid Cyclogenesis in the North Atlantic – Dynamics and Forecast Performance, Mon. Weather Rev., 139, 1861–1878,
https://doi.org/10.1175/2011MWR3504.1, 2011.
Bracegirdle, T. J. and Gray, S. L.: The dynamics of a polar low assessed using potential vorticity inversion, Q. J. Roy. Meteorol. Soc., 135, 880–893, https://doi.org/10.1002/qj.411, 2009.
Büeler, 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.
Buzzi, A., Davolio, S., and Fantini, M.: Cyclogenesis in the lee of the Alps:
a review of theories, Bull. Atmos. Sci. Technol., 1, 433–457, https://doi.org/10.1007/s42865-020-00021-6, 2020.
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.
Campins, J., Genovés, A., Picornell, M. A., and Jansà, A.: Climatology of Mediterranean cyclones using the ERA-40 dataset, Int. J.
Climatol., 31, 1596–1614, https://doi.org/10.1002/joc.2183, 2011.
Cao, J. and Xu, Q.: Computing Hydrostatic Potential Vorticity in Terrain-Following Coordinates, Mon. Weather Rev., 139, 2955–2961,
https://doi.org/10.1175/MWR-D-11-00083.1, 2011.
Carrió, D. S., Homar, V., Jansa, A., Romero, R., and Picornell, M. A.:
Tropicalization process of the 7 November 2014 Mediterranean cyclone: Numerical sensitivity study, Atmos. Res., 197, 300–312,
https://doi.org/10.1016/j.atmosres.2017.07.018, 2017.
Carrió, D. S., Homar, V., Jansà, A., Picornell, M. A., and Campins, J.: Diagnosis of a high-impact secondary cyclone during HyMeX-SOP1 IOP18,
Atmos. Res., 242, 104983, https://doi.org/10.1016/j.atmosres.2020.104983, 2020.
Cavicchia, L., von Storch, H., and Gualdi, S.: Mediterranean Tropical-Like
Cyclones in Present and Future Climate, J. Climate, 27, 7493–7501,
https://doi.org/10.1175/JCLI-D-14-00339.1, 2014.
Chaboureau, J.-P., Pantillon, F., Lambert, D., Richard, E., and Claud, C.:
Tropical transition of a Mediterranean storm by jet crossing, Q. J. Roy.
Meteorol. Soc., 138, 596–611, https://doi.org/10.1002/qj.960, 2012.
Chagnon, J. M., Gray, S. L., and Methven, J.: Diabatic processes modifying
potential vorticity in a North Atlantic cyclone, Q. J. Roy. Meteorol. Soc.,
139, 1270–1282, https://doi.org/10.1002/qj.2037, 2013.
Chagnon, J. M. and Gray, S. L.: A Diabatically Generated Potential Vorticity
Structure near the Extratropical Tropopause in Three Simulated Extratropical
Cyclones, Mon. Weather Rev., 143, 2337–2347, https://doi.org/10.1175/MWR-D-14-00092.1, 2015.
Chan, J. C.-L., Ko, F. M. F., and Lei, Y. M.: Relationship between potential
vorticity tendency and tropical cyclone motion, J. Atmos. Sci., 59, 1317–1336, 2002.
Charney, J.: The Use of the Primitive Equations of Motion in Numerical Prediction, Tellus, 7, 22–26, https://doi.org/10.1111/j.2153-3490.1955.tb01138.x, 1955.
Claud, C., Alhammoud, B., Funatsu, B. M., and Chaboureau, J.-P.: Mediterranean hurricanes: large-scale environment and convective and
precipitating areas from satellite microwave observations, Nat. Hazards
Earth Syst. Sci., 10, 2199–2213, https://doi.org/10.5194/nhess-10-2199-2010, 2010.
Dafis, S., Rysman, J.-F., Claud, C., and Flaounas, E.: Remote sensing of deep
convection within a tropical-like cyclone over the Mediterranean Sea, Atmos.
Sci. Lett., 19, e823, https://doi.org/10.1002/asl.823, 2018.
Davis, C. A.: Piecewise potential vorticity inversion, J. Atmos. Sci., 49,
1397–1411, 1992.
Davis, C. A. and Bosart, L. F.: The TT problem: Forecasting the tropical
transition of cyclones, B. Am. Meteorol. Soc., 85, 1657–1662, https://doi.org/10.1175/BAMS-85-11-1657, 2004.
Davis, C. A. and Emanuel, K. A.: Potential vorticity diagnostics of cyclogenesis, Mon. Weather Rev., 119, 1929–1953, 1991.
Decker, S. G.: Nonlinear Balance in Terrain-Following Coordinates, Mon. Weather Rev., 138, 605–624, 2010.
Deveson, A. C. L., Browning, K. A., and Hewson, T. D.: A classification of
FASTEX cyclones using a height-attributable quasi-geostrophic vertical-motion diagnostic, Q. J. Roy. Meteorol. Soc., 128, 93–117, https://doi.org/10.1256/00359000260498806, 2002.
Di Muzio, E., Riemer, M., Fink, A. H., and Maier-Gerber, M.: Assessing the
predictability of Medicanes in ECMWF ensemble forecasts using an object-based approach, Q. J. Roy. Meteorol. Soc., 145, 1202–1217, https://doi.org/10.1002/qj.3489, 2019.
Dudhia, J.: Numerical study of convection observed during the winter monsoon
experiment using a mesoscale two-dimensional model, J. Atmos. Sci., 46, 3077–3107, 1989.
Emanuel, K.: Genesis and maintenance of “Mediterranean hurricanes”, Adv.
Geosci., 2, 217–220, https://doi.org/10.5194/adgeo-2-217-2005, 2005.
Epifanio, C. C. and Durran, D. R.: Lee-vortex formation in free-slip stratified flow over ridges. Part II: Mechanisms of vorticity and PV production in nonlinear viscous wakes, J. Atmos. Sci., 59, 1166–1181, 2002.
Fita, L. and Flaounas, E.: Medicanes as subtropical cyclones: the December 2005 case from the perspective of surface pressure tendency diagnostics and atmospheric water budget, Q. J. Roy. Meteorol. Soc., 144, 1028–1044, https://doi.org/10.1002/qj.3273, 2018.
Fita, L., Romero, R., and Ramis, C.: Intercomparison of intense cyclogenesis
events over the Mediterranean basin based on baroclinic and diabatic influences, Adv. Geosci., 7, 333–342, https://doi.org/10.5194/adgeo-7-333-2006, 2006.
Fita, L., Romero, R., Luque, A., Emanuel, K., and Ramis, C.: Analysis of the
environments of seven Mediterranean tropical-like storms using an axisymmetric, nonhydrostatic, cloud resolving model, Nat. Hazards Earth
Syst. Sci., 7, 41–56, https://doi.org/10.5194/nhess-7-41-2007, 2007.
Flamant, C., Richard, E., Schär, C., Rotunno, R., Nance, L., Sprenger, M., and Benoit, R.: The wake south of the Alps: Dynamics and structure of the
lee-side flow and secondary potential vorticity banners, Q. J. Roy. Meteorol.
Soc., 130, 1275–1303, https://doi.org/10.1256/qj.03.17, 2004.
Flaounas, E., Kotroni, V., Lagouvardos, K., and Flaounas, I.: CycloTRACK (v1.0) – tracking winter extratropical cyclones based on relative
vorticity: sensitivity to data filtering and other relevant parameters,
Geosci. Model Dev., 7, 1841–1853, https://doi.org/10.5194/gmd-7-1841-2014, 2014.
Flaounas, E., Raveh-Rubin, S., Wernli, H., Drobinski, P., and Bastin, S.: The
dynamical structure of intense Mediterranean cyclones, Clim. Dynam., 44, 2411–2427, https://doi.org/10.1007/s00382-014-2330-2, 2015.
Flaounas, E., Kelemen, F. D., Wernli, H., Gaertner, M. A., Reale, M.,
Sanchez-Gomez, E., Lionello, P., Calmanti, S., Podrascanin, Z., Somot, S.,
Akhtar, N., Romera, R., and Conte, D.: Assessment of an ensemble of
ocean–atmosphere coupled and uncoupled regional climate models to reproduce
the climatology of Mediterranean cyclones, Clim. Dynam., 51, 1023–1040,
https://doi.org/10.1007/s00382-016-3398-7, 2018a.
Flaounas, E., Kotroni, V., Lagouvardos, K., Gray, S. L., Rysman, J.-F., and
Claud, C.: Heavy rainfall in Mediterranean cyclones. Part I: contribution of
deep convection and warm conveyor belt, Clim. Dynam., 50, 2935–2949,
https://doi.org/10.1007/s00382-017-3783-x, 2018b.
Flaounas, E., Fita, L., Lagouvardos, K., and Kotroni, V.: Heavy rainfall in
Mediterranean cyclones, Part II: Water budget, precipitation efficiency and
remote water sources, Clim. Dynam., 53, 2539–2555, https://doi.org/10.1007/s00382-019-04639-x, 2019.
Galanaki, E., Flaounas, E., Kotroni, V., Lagouvardos, K., and Argiriou, A.:
Lightning activity in the Mediterranean: quantification of cyclones contribution and relation to their intensity: Mediterranean cyclones associated with lightning activity, Atmos. Sci. Lett., 17, 510–516,
https://doi.org/10.1002/asl.685, 2016.
Gray, S. L.: Mechanisms of midlatitude cross-tropopause transport using a
potential vorticity budget approach, J. Geophys. Res., 111, D17113,
https://doi.org/10.1029/2005JD006259, 2006.
Gray, S. L. and Dacre, H. F.: Classifying dynamical forcing mechanisms using a climatology of extratropical cyclones, Q. J. Roy. Meteorol. Soc., 132,
1119–1137, https://doi.org/10.1256/qj.05.69, 2006.
Hanley, J. and Caballero, R.: Objective identification and tracking of multicentre cyclones in the ERA-Interim reanalysis dataset, Q. J. Roy. Meteorol. Soc., 138, 612–625, https://doi.org/10.1002/qj.948, 2012.
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., Thépaut, J.-N.: ERA5 hourly data on pressure levels from 1979 to present, Copernicus Climate Change Service (C3S) Climate Data Store (CDS), https://doi.org/10.24381/cds.bd0915c6, 2018.
Hong, S., Dudhia, J., and Chen, S.: A Revised Approach to Ice Microphysical Processes for the Bulk Parameterization of Clouds and Precipitation, Mon. Weather Rev., 132, 103–120, 2004.
Hong, S.-Y.: A new stable boundary-layer mixing scheme and its impact on the
simulated East Asian summer monsoon, Q. J. Roy. Meteorol. Soc., 136, 1481–1496, https://doi.org/10.1002/qj.665, 2010.
Hong, S. Y., Juang, H. M. H., and Zhao, Q.: Implementation of prognostic cloud scheme for a regional spectral model, Mon. Weather Rev., 126, 2621–2639, 1998.
Hong, S.-Y., Noh, Y., and Dudhia, J.: A New Vertical Diffusion Package with an Explicit Treatment of Entrainment Processes, Mon. Weather Rev., 134, 2318–2341, https://doi.org/10.1175/MWR3199.1, 2006.
Huo, Z., Zhang, D. L., and Gyakum, J. R.: Interaction of potential vorticity
anomalies in extratropical cyclogenesis. Part I: Static piecewise inversion,
Mon. Weather Rev., 127, 2546–2562, 1999.
Kain, J. S.: The Kain–Fritsch convective parameterization: an update, J.
Appl. Meteorol., 43, 170–181, 2004.
Kouroutzoglou, J., Flocas, H. A., Keay, K., Simmonds, I., and Hatzaki, M.:
Climatological aspects of explosive cyclones in the Mediterranean, Int. J.
Climatol., 31, 1785–1802, https://doi.org/10.1002/joc.2203, 2011.
Lackmann, G. M.: Cold-frontal potential vorticity maxima, the low-level jet,
and moisture transport in extratropical cyclones, Mon. Weather Rev., 130,
59–74, https://doi.org/10.1175/1520-0493(2002)130<0059:cfpvmt>2.0.co;2, 2002.
Lagouvardos, K., Kotroni, V., and Defer, E.: The 21–22 January 2004 explosive cyclogenesis over the Aegean Sea: Observations and model analysis, Q. J. Roy. Meteorol. Soc., 133, 1519–1531, https://doi.org/10.1002/qj.121, 2007.
Lamarque, J.-F. and Hess, P. G.: Cross-tropopause mass exchange and potential vorticity budget in a simulated tropopause folding, J. Atmos. Sci., 51, 2246–2269, 1994.
Maheras, P., Flocas, H. A., Patrikas, I., and Anagnostopoulou, Chr.: A 40 year objective climatology of surface cyclones in the Mediterranean region: spatial and temporal distribution, Int. J. Climatol., 21, 109–130,
https://doi.org/10.1002/joc.599, 2001.
Martínez-Alvarado, O., Gray, S. L., and Methven, J.: Diabatic Processes and the Evolution of Two Contrasting Summer Extratropical Cyclones, Mon.
Weather Rev., 144, 3251–3276, https://doi.org/10.1175/MWR-D-15-0395.1, 2016.
McTaggart-Cowan, R., Galarneau, T. J., Bosart, L. F., and Milbrandt, J. A.:
Development and Tropical Transition of an Alpine Lee Cyclone. Part I: Case
Analysis and Evaluation of Numerical Guidance, Mon. Weather Rev., 138, 2281–2307, https://doi.org/10.1175/2009MWR3147.1, 2010a.
McTaggart-Cowan, R., Galarneau, T. J., Bosart, L. F., and Milbrandt, J. A.:
Development and Tropical Transition of an Alpine Lee Cyclone. Part II:
Orographic Influence on the Development Pathway, Mon. Weather Rev., 138,
2308–2326, https://doi.org/10.1175/2009MWR3148.1, 2010b.
Miglietta, M. M. and Rotunno, R.: Development mechanisms for Mediterranean
tropical-like cyclones (medicanes), Q. J. Roy. Meteorol. Soc., 145, 1444–1460, https://doi.org/10.1002/qj.3503, 2019.
Miglietta, M. M., Moscatello, A., Conte, D., Mannarini, G., Lacorata, G., and
Rotunno, R.: Numerical analysis of a Mediterranean `hurricane' over south-eastern Italy: Sensitivity experiments to sea surface temperature, Atmos. Res., 101, 412–426, https://doi.org/10.1016/j.atmosres.2011.04.006, 2011.
Miglietta, M. M., Laviola, S., Malvaldi, A., Conte, D., Levizzani, V., and
Price, C.: Analysis of tropical-like cyclones over the Mediterranean Sea
through a combined modeling and satellite approach, Geophys. Res. Lett., 40, 2400–2405, https://doi.org/10.1002/grl.50432, 2013.
Miglietta, M. M., Mastrangelo, D., and Conte, D.: Influence of physics
parameterization schemes on the simulation of a tropical-like cyclone in the
Mediterranean Sea, Atmos. Res., 153, 360–375, https://doi.org/10.1016/j.atmosres.2014.09.008, 2015.
Miglietta, M. M., Cerrai, D., Laviola, S., Cattani, E., and Levizzani, V.:
Potential vorticity patterns in Mediterranean “hurricanes,” Geophys. Res.
Lett., 44, 2537–2545, https://doi.org/10.1002/2017GL072670, 2017.
Mlawer, E. J., Taubman, S. J., Brown, P. D., Iacono, M. J., and Clough, S. A.: Radiative transfer for inhomogeneous atmospheres: RRTM, a validated
correlated-k model for the longwave, J. Geophys. Res., 102, 16663–16682, https://doi.org/10.1029/97JD00237, 1997.
Möller, J. D. and Montgomery, M. T.: Tropical cyclone evolution via potential vorticity anomalies in a three-dimensional balancemodel, J. Atmos.
Sci., 57, 3366–3387, 2000.
Nastos, P. T., Papadimou, K., and Matsangouras, I. T.: Mediterranean tropical-like cyclones: Impacts and composite daily means and anomalies of
synoptic patterns, Atmos. Res., 208, 156–166,
https://doi.org/10.1016/j.atmosres.2017.10.023, 2018.
Neu, U., Akperov, M. G., Bellenbaum, N., Benestad, R., Blender, R., Caballero, R., Cocozza, A., Dacre, H. F., Feng, Y., Fraedrich, K., Grieger,
J., Gulev, S., Hanley, J., Hewson, T., Inatsu, M., Keay, K., Kew, S. F., Kindem, I., Leckebusch, G. C., Liberato, M. L. R., Lionello, P., Mokhov, I.
I., Pinto, J. G., Raible, C. C., Reale, M., Rudeva, I., Schuster, M., Simmonds, I., Sinclair, M., Sprenger, M., Tilinina, N. D., Trigo, I. F.,
Ulbrich, S., Ulbrich, U., Wang, X. L., and Wernli, H.: IMILAST: A community
effort to intercompare extratropical cyclone detection and tracking
algorithms, B. Am. Meteorol. Soc., 94, 529–547, https://doi.org/10.1175/BAMS-D-11-00154.1, 2013.
Nissen, K. M., Leckebusch, G. C., Pinto, J. G., Renggli, D., Ulbrich, S., and
Ulbrich, U.: Cyclones causing wind storms in the Mediterranean: characteristics, trends and links to large-scale patterns, Nat. Hazards
Earth Syst. Sci., 10, 1379–1391, https://doi.org/10.5194/nhess-10-1379-2010, 2010.
Petterssen, S.: Weather analysis and forecasting. McGraw-Hill, New York, 1956.
Piaget, N., Froidevaux, P., Giannakaki, P., Gierth, F., Martius, O., Riemer,
M., Wolf, G., and Grams, C. M.: Dynamics of a local Alpine flooding event in
October 2011: moisture source and large-scale circulation: Dynamics of a Local Alpine Flooding Event, Q. J. Roy. Meteorol. Soc., 141, 1922–1937,
https://doi.org/10.1002/qj.2496, 2015.
Plant, R. S., Craig, G. C., and Gray, S. L.: On a threefold classification of
extratropical cyclogenesis, Q. J. Roy. Meteorol. Soc., 129, 2989–3012,
https://doi.org/10.1256/qj.02.174, 2003.
Prezerakos, N. G., Flocas, H. A., and Brikas, D.: The role of the interaction
between polar and subtropical jet in a case of depression rejuvenation over the Eastern Mediterranean, Meteorol. Atmos. Phys., 92, 139–151,
https://doi.org/10.1007/s00703-005-0142-y, 2006.
Price, C., Asfur, M., and Yair, Y.: Maximum hurricane intensity preceded by
increase in lightning frequency, Nat. Geosci., 2, 329–332, https://doi.org/10.1038/ngeo477, 2009.
Pytharoulis, I., Kartsios, S., Tegoulias, I., Feidas, H., Miglietta, M.,
Matsangouras, I., and Karacostas, T.: Sensitivity of a Mediterranean Tropical-Like Cyclone to Physical Parameterizations, Atmosphere, 9, 436,
https://doi.org/10.3390/atmos9110436, 2018.
Pytharoulis, I.: Analysis of a Mediterranean tropical-like cyclone and its
sensitivity to the sea surface temperatures, Atmos. Res., 208, 167–179, https://doi.org/10.1016/j.atmosres.2017.08.009, 2018.
Raveh-Rubin, S. and Flaounas, E.: A dynamical link between deep Atlantic
extratropical cyclones and intense Mediterranean cyclones: Dynamics upstream
intense Mediterranean cyclones, Atmos. Sci. Lett, 18, 215–221,
https://doi.org/10.1002/asl.745, 2017.
Raveh-Rubin, S. and Wernli, H.: Large-scale wind and precipitation extremes
in the Mediterranean: a climatological analysis for 1979–2012: Mediterranean
Large-scale Wind and Precipitation Extremes, Q. J. Roy. Meteorol. Soc, 141,
2404–2417, https://doi.org/10.1002/qj.2531, 2015.
Rotunno, R., Grubišić, V., and Smolarkiewicz, P. K.: Vorticity and
Potential Vorticity in Mountain Wakes, J. Atmos. Sci., 56, 2796–2810, 1999.
Saffin, L., Methven, J., and Gray, S. L.: The non-conservation of potential
vorticity by a dynamical core compared with the effects of parametrized physical processes: Dynamical Core PV, Q. J. Roy. Meteorol. Soc., 142,
1265–1275, https://doi.org/10.1002/qj.2729, 2016.
Schär, C. and Durran, D. R.: Vortex Formation and Vortex Shedding in
Continuously Stratified Flows past Isolated Topography, J. Atmos. Sci., 54,
534–554, 1997.
Schär, C., Sprenger, M., Lüthi, D., Jiang, Q., Smith, R. B., and Benoit, R.: Structure and dynamics of an Alpine potential-vorticity banner,
Q. J. Roy. Meteorol. Soc., 129, 825–855, https://doi.org/10.1256/qj.02.47, 2003.
Schlemmer, L., Martius, O., Sprenger, M., Schwierz, C., and Twitchett, A.:
Disentangling the Forcing Mechanisms of a Heavy Precipitation Event along
the Alpine South Side Using Potential Vorticity Inversion, Mon. Weather Rev.,
138, 2336–2353, https://doi.org/10.1175/2009MWR3202.1, 2010.
Schneidereit, A., Peters, D. H. W., Grams, C. M., Quinting, J. F., Keller,
J. H., Wolf, G., Teubler, F., Riemer, M., and Martius, O.: Enhanced tropospheric wave forcing of two anticyclones in the prephase of the January 2009 major stratospheric sudden warming event, Mon. Weather Rev., 145, 1797–1815, https://doi.org/10.1175/MWR-D-16-0242.1, 2017.
Schubert, W. H., Hausman, S. A., Garcia, M., Ooyama, K. V., and Kuo, H.-C.:
Potential vorticity in a moist atmosphere, J. Atmos. Sci., 58, 3148–3157,
2001.
Seiler, C.: A Climatological Assessment of Intense Extratropical Cyclones from the Potential Vorticity Perspective, J. Climate, 32, 2369–2380,
https://doi.org/10.1175/JCLI-D-18-0461.1, 2019.
Skamarock, W. C., Klemp, J. B., Dudhia, J., Gill, D. O., Barker, D. M., Duda, M., Huang, X. Y., Wang, W., and Powers, J. G.: A description of the advanced research WRF version3, 603NCAR, Tech. Note, Mesoscale and Microscale Meteorology Division, National Center for Atmospheric Research, Boulder, Colorado, USA, 2008.
Spreitzer, E., Attinger, R., Boettcher, M., Forbes, R., Wernli, H., and Joos,
H.: Modification of Potential Vorticity near the Tropopause by Nonconservative Processes in the ECMWF Model, J. Atmos. Sci., 76, 1709–1726, https://doi.org/10.1175/JAS-D-18-0295.1, 2019.
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, 1996
Teubler, F. and Riemer, M.: Dynamics of Rossby wave packets in a quantitative potential vorticity–potential temperature framework, J. Atmos. Sci., 73, 1063–1081, https://doi.org/10.1175/JAS-D-15-0162.1, 2016.
Teubler, F. and Riemer, M.: Potential-Vorticity Dynamics of Troughs and Ridges within Rossby Wave Packets during a 40-year reanalysis period, Weather Clim. Dynam. Discuss. [preprint], https://doi.org/10.5194/wcd-2020-52, in review, 2020.
Tous, M. and Romero, R.: Meteorological environments associated with medicane development, Int. J. Climatol., 33, 1–14, https://doi.org/10.1002/joc.3428, 2013.
Tsidulko, M. and Alpert, P.: Synergism of upper-level potential vorticity and mountains in Genoa lee cyclogenesis – A numerical study, Meteorol. Atmos. Phys., 78, 261–285, https://doi.org/10.1007/s703-001-8178-8, 2001.
Vannière, B., Czaja, A., Dacre, H., Woollings, T., and Parfitt, R.: A
potential vorticity signature for the cold sector of winter extratropical
cyclones, Q. J. Roy. Meteorol. Soc., 142, 432–442, https://doi.org/10.1002/qj.2662, 2016.
Whittaker, I. C., Douma, E., Rodger, C. J., and Marshall, T. J. C. H.: A
quantitative examination of lightning as a predictor of peak winds in tropical cyclones, J. Geophys. Res.-Atmos., 120, 3789–3801,
https://doi.org/10.1002/2014JD022868, 2015.
Wu, C. C. and Emanuel, K. A.: Potential vorticity diagnostics of hurricane
movement. Part 1: A case study of Hurricane Bob (1991), Mon. Weather Rev., 123, 69–92, 1995.
Zhang, C. and Wang, Y.: Projected Future Changes of Tropical Cyclone Activity over the Western North and South Pacific in a 20-km-Mesh Regional Climate Model, J. Climate, 30, 5923–5941, https://doi.org/10.1175/JCLI-D-16-0597.1, 2017.
Short summary
In this study, we quantify the relative contribution of different atmospheric processes to the development of 100 intense Mediterranean cyclones and show that both upper tropospheric systems and diabatic processes contribute to cyclone development. However, these contributions are complex and present high variability among the cases. For this reason, we analyse several exemplary cases in more detail, including 10 systems that have been identified in the past as tropical-like cyclones.
In this study, we quantify the relative contribution of different atmospheric processes to the...
