The role of the export of tropical moisture into midlatitudes for extreme precipitation events in the Mediterranean region
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The aims of the study are twofold: firstly, to investigate the role of the export of humid tropical air in the formation of cool season heavy precipitating events (HPEs) in the Mediterranean region (MR); and secondly, to examine the possible linkage between the export of humid tropical air and the multiyear trend in extreme precipitation in the region. For this purpose, we analyze the spatial distributions of a number of key atmospheric variables with a reanalysis data for more than 50 intense HPEs for the MR. The results of this evaluation for both individual and composite events suggest that the HPEs are associated with atmospheric rivers (ARs). The MR HPEs are being characterized by the poleward export of humid air of tropical origin into the midlatitude MR from the Atlantic Ocean and Arabian Sea. These export events appear to be associated with the effects of hurricanes or intense cyclones in the North Atlantic. It was also found that the linear trend (for 1979–2013) of the frequency of humid days (days with precipitable water greater than 20 kg m−2) is consistent with recent changes in the character of precipitation over the MR and southern Europe.
KeywordsMediterranean Region Extreme Precipitation Precipitable Water Convective Available Potential Energy Eastern Mediterranean Region
The financial support for this work has been provided by The United States-Israel Binational Science Foundation (BSF) under research grant no. 2008436, the United States National Science Foundation (NSF) under grants AGS-1036858 and AGS-1401220, Research Grant 4500568707 for 2011–2013 by the Israeli Water Authority of the Ministry of Infrastructures, and the European Union Sixth Framework programme project Climate Change and Impact Research: Mediterranean Environment (CIRCE) [www.circeproject.eu] under contract GOCE-036961. This work is also a contribution to the Hydrological Cycle in Mediterranean Experiment (HyMex) and The Northern Eurasian Earth Science Partnership Initiative (NEESPI). One of the authors (SG) thanks the projects GEMINA and NextData funded by the Italian Ministries of University and Research (MIUR) and of Environment (MATT). Discussions supported through the European Cooperation in Science and Technology (COST) Earth System Science and Environmental Management (ESSEM) Action ES0905 “Basic concepts for convection parameterization in weather forecast and climate models” and the WMO MEDEX and European Science Foundation MedClivar programs are also acknowledged. Additionally, the authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model and/or READY website (http://www.ready.noaa.gov) used in this publication. Finally, we acknowledge the use of the NCEP Reanalysis data provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, USA from their website at http://www.esrl.noaa.gov/psd/; of the data from the 20th Century Reanalysis from the website http://www.esrl.noaa.gov/psd/data/20thC_Rean/; as well as the use of the maps of indices of precipitation extremes and their multiyear trends during the twentieth century over the European region available at the website (http://eca.knmi.nl/) of the European Climate Assessment & Dataset project (ECA). The authors thank two anonymous reviewers for their insightful comments.
- Avila LA (2001) Hurricane Olga, 24 November–4 December 2001. Tropical cyclone report. [Available online at http://www.nhc.noaa.gov/2001olga.html]
- Bancroft GP (2003) Marine weather review—North Atlantic Area September 2002 to February 2003, Mariners Wea. Log, NOAA, 47, 1, 8 ppGoogle Scholar
- Draxler RR, Rolph GD (2013) HYSPLIT (HYbrid Single-Particle Lagrangian Integrated Trajectory) model access via NOAA ARL READY Website (http://www.arl.noaa.gov/HYSPLIT.php). NOAA Air Resources Laboratory, College Park, MD
- Gualdi S, Somot S, May W, Castellari S, Déqué M, Adani M, Artale V, Bellucci A, Breitgand JS, Carillo A, Cornes R, Dell’Aquila A, Dubois C, Efthymiadis D, Elizalde A, Gimeno L, Goodess CM, Harzallah A, Krichak SO, Kuglitsch FG, Leckebusch GC, L’Heveder B, Li L, Lionello P, Luterbacher J, Mariotti A, Nieto R, Nissen KM, Oddo P, Ruti P, Sanna A, Sannino G, Scoccimarro E, Sevault F, Struglia MV, Toreti A, Ulbrich U, Xoplaki E (2013) Future climate projections. In: Navarra A, Tubiana L (eds) Regional assessment of climate change in the Mediterranean. Springer, Dordrecht, 870 pGoogle Scholar
- Lionello P, Bhend J, Buzzi A, Della-Marta PM, Krichak SO, Jansa A, Maheras P, Sanna A, Trigo IF, Trigo R (2006) Cyclones in the Mediterranean region: climatology and effects on the environment. In: Lionello P, Malanotte-Rizzoli P, Boscolo R (eds) Mediterranean climate variability, 4. Elsevier, Amsterdam, pp 325–372Google Scholar
- Pinto JG, Klawa M, Ulbrich U, Rudari R, Speth P (2001) Extreme precipitation events over southwestern Italy and their relationship with tropical–extratropical interactions over the Atlantic Mediterranean storms. Proc. Third Plinius Conf., Baja Sardinia, Italy, European Geophysical Society, GNDCI Publication 2560:327–332Google Scholar
- Ramis C, Jansá A, Alonso S, Heredia MA (1986) Convection over the western Mediterranean. Synoptic study and remote observation (in Spanish). Rev Meteorol 7:59–82Google Scholar
- Zhang X, He J, Zhang J, Polyakov I, Gerdes R, Inoue J, Wu P (2013) Enhanced poleward moisture transport and amplified northern high-latitude wetting trend. Nat Clim Chang 3, doi: 10.1038/NCIMATE1631