Medicanes: cataloguing criteria and exploration of meteorological environments
Tethys no. 8 pp.: 53 - 61
Depressions with a similar structure to tropical cyclones, that can reach the intensity of hurricanes, are occasionally generated in the Mediterranean. Such phenomena are called “medicanes”. Although the geographical dimensions of tropical oceans and the Mediterranean Sea are clearly different, the precursor mechanisms of these perturbations, based on the air-sea thermodynamic imbalance, are similar. This fact made us think about the existence of a physical parallelism between both phenomena. We tried to identify such cases from historical images of the Meteosat satellite, for the period 1982-2005. Different lists have been created, each of them increasingly delimiting the selection criteria based on the cyclone structure in the infrared channel. Some of these criteria are, for instance, the size of the cyclone, the clear existence of an eye and the lifetime of the system. This identification has been made in a subjective way. In total, twelve cases of medicanes were identified. The characterization of meteorological environments that are a precursor to medicanes can help us understand the genesis mechanisms and to improve forecasts. This study compares the values of several meteorological variables of interest in the cases of medicanes with those of cyclones catalogued in the database of the MEDEX project to try to identify the environments that favor the genesis and development of medicanes instead of other Mediterranean cyclones. In this sense, the sea surface temperature, the diabatic contribution to the local trend of surface equivalent potential temperature and an empirical index derived from the genesis of tropical cyclones are presented as possible discriminatory parameters.
- - Campins, J., Genovés, A., Picornell, M., and Jansà, A., 2010: Climatology of Mediterranean cyclones using the ERA-40 dataset, Int J Climatol, 31, doi: 10.1002/joc.2183.
- - Emanuel, K., 2003: Tropical cyclones, Annu Rev Earth Planet Sci, 31, 75–104.
- - Emanuel, K., 2005: Genesis and maintenance of Mediterranean hurricanes, Adv Geosci, 2, 217–220, doi: 10.5194/adgeo-2-217-2005.
- - Ernest, J. and Matson, M., 1983: A Mediterranean tropical storm?, Weather, 38, 332–337.
- - Homar, V., Romero, R., Stensrud, D., Ramis, C., and Alonso, S., 2003: Numerical Diagnosis of a Small, Quasi-Tropical Cyclone over the Western Mediterranean: Dynamical vs. boundary factors, Q J R Meteorol Soc, 129, 1469–1490, doi: 10.1256/qj.01.91.
- - Jansà, A., 2003: Miniciclons a la Mediterrània, IX Jornades de Meteorologia Eduard Fontserè, Associació Catalana de Meteorologia (ACAM), Barcelona, ISBN: 84-930328-6-7, 75-85.
- - Mayengon, R., 1984: Warm core cyclones in the Mediterranean, Mariners Weather Log, 28, 6–9.
- - Picornell, M., Jansà, A., Genovés, A., and Campins, J., 2001: Automated database of mesocyclones from the Hirlam(INM)-0.5 analyses in the western mediterranean, Int J Climatol, 21, 335–354, doi: 10.1002/joc.621.
- - Pytharoulis, I., Craig, G., and Ballard, S., 2000: The hurricane-like Mediterranean cyclone of January 1995, Meteorol Appl, 7, 261–279, doi: 10.1017/S1350482700001511.
- - Reale, O. and Atlas, R., 2001: Tropical cyclone-like vortices in the extratropics: observational evidence and synoptic analysis, Weather Forecast, 16, 7–34, doi: 10.1175/1520-0434(2001)016<0007:TCLVIT>2.0.CO;2.
- - Romero, R. and Emanuel, K., 2006: Space-time probability density of Mediterranean hurricane genesis in the light of an empirical tropical index, 5a Assambleia Luso-Espanhola de Geodesia e Geofisica, Sevilla, CD-Rom, Ministerio Medio Ambiente, ISBN: 84-8320-373-1.
- - Tous, M., Genovés, A., Campins, J., Picornell, M., Jansà, A., and Mizuta, R., 2009: Mediterranean Cyclones in a changing climate. Results from JMA-GSM model, 11th Plinius Conference on Mediterranean Storms, Barcelona, final Book programme, 11, p. 102.
This work is licensed under a Creative Commons Attribution 3.0 Unported License
Indexed in Scopus, Scientific Commons, Latindex, Google Scholar, DOAJ, ICYT (CSIC)
Partially funded through grants CGL2007-29820-E/CLI, CGL2008-02804-E/, CGL2009-07417-E and CGL2011-14046-E of the Spanish Ministry of Science and Innovation