Flaounas et al. (2022) Mediterranean cyclones: current knowledge and open questions on dynamics, prediction, climatology and impacts

Identification

Journal: Weather and Climate Dynamics
Year: 2022
Date: 2022-02-14
Authors: Emmanouil Flaounas, Silvio Davolio, Shira Raveh‐Rubin, Florian Pantillon, Mario Marcello Miglietta, Μiguel Angel Gaertner, Maria Hatzaki, V. Homar, Samira Khodayar, Γεράσιμος Κορρές, Vassiliki Kotroni, Jonilda Kushta, Marco Reale, Didier Ricard
DOI: 10.5194/wcd-3-173-2022

Research Groups

Institute of Oceanography, Hellenic Centre for Marine Research, Athens, Greece
Institute of Atmospheric Sciences and Climate (CNR-ISAC), National Research Council of Italy, Bologna and Padua, Italy
Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot, Israel
Laboratoire d’Aérologie, Université de Toulouse, CNRS, UPS, IRD, Toulouse, France
Faculty of Environmental Sciences and Biochemistry, University of Castilla-La Mancha, Toledo, Spain
Department of Geology and Geoenvironment, National and Kapodistrian University of Athens, Athens, Greece
Meteorology Group, Physics Department, Universitat de les Illes Balears, Palma, Mallorca, Spain
Mediterranean Centre for Environmental Studies (CEAM), Valencia, Spain
Institute of Environmental Research and Sustainable Development, National Observatory of Athens (NOA), Athens, Greece
Climate and Atmosphere Research Centre (CARE-C), The Cyprus Institute, Nicosia, Cyprus
National Institute of Oceanography and Applied Geophysics – OGS, Trieste, Italy
Abdus Salam International Centre for Theoretical Physics (ICTP), Trieste, Italy
CNRM, Université de Toulouse, Météo-France, CNRS, Toulouse, France

Short Summary

This paper reviews the current state of knowledge on Mediterranean cyclones, encompassing their climatology, dynamics, prediction, and impacts, while also identifying key open questions and future research directions. It highlights significant advancements in the field, emphasizing the ongoing need for coordinated, interdisciplinary research to address remaining challenges.

Objective

To review the status of knowledge in the broad field of Mediterranean cyclones, focusing on their climatology, dynamics, prediction, and impacts.
To outline future research directions and open questions that require coordinated and interdisciplinary efforts to advance the understanding and forecasting of these high-impact weather systems.

Study Configuration

Spatial Scale: Mediterranean basin (western, central, eastern), North Atlantic Ocean, Europe, North Africa, Alps, Tyrrhenian Sea, Adriatic Sea, Ionian Sea, Aegean Sea, Black Sea, Levantine basin, Gulf of Genoa, Gulf of Cadiz, Algerian Sea, Iberian Peninsula, Red Sea, South Asia, Central Europe, Italy, France, Spain, Greece, Cyprus, Malta, Newfoundland.
Temporal Scale: Review of studies spanning several decades (e.g., 1950s-2020s), with specific datasets covering periods like 1980-2015, 1950-2011, 1979-2010, 2001-2011, 1980-2018, 2001-2010. Focus on seasonal cycles (winter, summer, autumn, spring) and future climate projections (21st century, 2051-2100).

Methodology and Data

Models used: Global Climate Models (GCMs) such as ECHAM4 and CMIP5; Regional Climate Models (RCMs) including Med-CORDEX ensemble (coupled and uncoupled ocean-atmosphere RCMs, RCSMs), Weather Research and Forecasting (WRF) model, BOLogna Limited Area Model (BOLAM), AROME-WMED, COSMO-H2-EPS, and PEARP; Axisymmetric, nonhydrostatic, cloud-resolving models; Ensemble Prediction Systems (EPSs).
Data sources: Reanalysis datasets (ECMWF operational analyses, ERA-40, ERA-Interim, ERA5); Satellite data (MSG-SEVIRI, Tropical Rainfall Measuring Mission (TRMM), microwave humidity sounder (MHS) radiometer, Aeolus Doppler wind lidar satellite mission); Ground-based observations (lightning observations from ZEUS, visibility observations, PM10 dust concentrations); Databases (MEDEX, HyMeX Special Observation Periods (SOPs), FLOODHYMEX, Mediterranean Flood Fatalities (MEFF), European Flood Fatalities (EUFF), International Maritime Organization (IMO) database for ship accidents); Cyclone tracking methods (IMILAST dataset); Diagnostic tools (cyclone phase-space analysis, factor separation techniques, piecewise potential vorticity (PV) inversion, data targeting systems (DTS), ensemble Kalman filters (EnKFs), stochastic perturbations).

Main Results

Mediterranean cyclones are frequent, intense, and responsible for severe socio-economic and environmental impacts, making the region a climate change hotspot.
Climatologically, cyclogenesis is most frequent in winter (northern and central Mediterranean) and autumn (for medicanes), with a minimum in summer (often shallow systems over North Africa). Intense cyclones frequently form in the northwest Mediterranean.
Future climate projections (e.g., CMIP5, RCP8.5 scenarios) indicate a robust overall reduction in Mediterranean cyclone occurrence but a projected increase in intensity, particularly for medicanes, largely attributed to rising sea surface temperatures.
Mediterranean cyclone dynamics are primarily driven by baroclinic instability, often initiated by southward intrusions of high potential vorticity (PV) air masses (Rossby wave breaking, PV streamers/cut-offs), and are significantly modulated by diabatic processes (latent heat release from convection) and complex topography (e.g., lee cyclogenesis).
Airstreams such as Warm Conveyor Belts (WCBs) and Dry Air Intrusions (DIs) are crucial for precipitation and wind extremes, with WCBs contributing 50 % to 60 % of extreme precipitation events.
Medicanes, rare tropical-like cyclones, typically evolve from baroclinic systems, with their development highly sensitive to sea surface temperatures, wind shear, and convection. They are projected to decrease in frequency but increase in intensity.
Forecasting Mediterranean cyclones is challenging due to their multiscale nature, complex topography, and sparse observations. Predictability is strongly linked to the accurate prediction of large-scale atmospheric circulation, particularly the evolution of the North Atlantic Rossby wave train.
High-resolution models (convection-permitting) and coupled atmosphere-ocean-wave systems show promise for improved forecasts but necessitate advancements in physical parameterizations (microphysics, turbulence) and more effective observation assimilation strategies.
Cyclones are the primary drivers of high-impact weather in the region, contributing over 70 % of annual total precipitation and up to 90 % of extreme rainfall events, as well as causing flash floods, windstorms, storm surges, high sea waves, and significant dust transport events (10 % to 25 % of total, 30 % to 70 % of extreme dust events).

Contributions

Provides a comprehensive, up-to-date review of the scientific understanding of Mediterranean cyclones, synthesizing knowledge across climatology, dynamics, prediction, and impacts.
Identifies critical open questions and outlines specific future research priorities, encouraging coordinated and interdisciplinary approaches within the scientific community.
Highlights the need to balance asymmetric progress in different subdomains and geographical regions of Mediterranean cyclone research.
Emphasizes the importance of advanced modeling techniques (e.g., high-resolution, coupled atmosphere-ocean-wave systems) and enhanced observational strategies for improving understanding and forecast skill.
Serves as a foundational document to guide and support future international collaborative efforts, such as the COST Action CA19109 MedCyclones.

Funding

COST Action CA19109 “MedCyclones” (European Cooperation in Science and Technology)
Italian Ministry for Education, University and Research (MIUR) project “Climate change: risk mitigation for sustainable development”
Spanish Ministry of Science, Innovation and Universities, Spanish State Research Agency, and European Regional Development Fund through grant CGL2017-89583-R (IBERTROPIC project)
Talented Researchers Support Programme – Pla GenT – CIDEGENT by the Ministry of Innovation, Universities, Science and Digital Society, Generalitat Valenciana (GVA), project MED-EXTREME (CIDEGENT/2018/017)
OGS and CINECA under HPC-TRES award number 2015-07
Project FAIRSEA (Fisheries in the Adriatic Region – a Shared Ecosystem Approach) funded by the 2014–2020 Interreg V-A Italy–Croatia CBC Programme (standard project ID 10046951)
Spanish Ministry of Science, Innovation and Universities, Spanish State Research Agency, and European Regional Development Fund through grant CGL2017-82868-R (COASTEPS)
De Botton Center for Marine Science
EMME-CARE project (European Union’s Horizon 2020 Research and Innovation Programme under grant agreement no. 856612 and the Cyprus Government)

Citation

@article{Flaounas2022Mediterranean,
  author = {Flaounas, Emmanouil and Davolio, Silvio and Raveh‐Rubin, Shira and Pantillon, Florian and Miglietta, Mario Marcello and Gaertner, Μiguel Angel and Hatzaki, Maria and Homar, V. and Khodayar, Samira and Κορρές, Γεράσιμος and Kotroni, Vassiliki and Kushta, Jonilda and Reale, Marco and Ricard, Didier},
  title = {Mediterranean cyclones: current knowledge and open questions on dynamics, prediction, climatology and impacts},
  journal = {Weather and Climate Dynamics},
  year = {2022},
  doi = {10.5194/wcd-3-173-2022},
  url = {https://doi.org/10.5194/wcd-3-173-2022}
}

Original Source: https://doi.org/10.5194/wcd-3-173-2022