ACPD Atmospheric Chemistry and Physics Discussions ACPD 1680-7375 Copernicus GmbH Göttingen, Germany 10.5194/acpd-9-21425-2009 Origin and transport of Mediterranean moisture and air Schicker I. 1 Radanovics S. 1 Seibert P. 1 Institute of Meteorology, University of Natural Resources and Applied Life Sciences, Vienna, Austria 12 10 2009 9 5 21425 21461 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys-discuss.net/9/21425/2009/acpd-9-21425-2009.html The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/9/21425/2009/acpd-9-21425-2009.pdf

Considering the Mediterranean as a region of high evaporation and low precipitation, evaluations of the moisture and precipitation sources and sinks in the Mediterranean basin have been carried out within the frame of the CIRCE project. In addition, residence time and stagnation/ventilation have been analysed to investigate transport to and from the Mediterranean basin and in the basin itself. A Lagrangian moisture diagnosis method calculating budgets of evaporation minus precipitation was applied to a 5.5 year (October 1999–April 2005) trajectory data set and evaluated for eight Mediterranean regions of interest. The Mediterranean basin has been identified as a major source of moisture and precipitation to the surrounding land area and to the basin itself. Regions of stagnation have been identified through the analysis of the average 24-hour and 5-day displacements for the four seasons, and the Po basin was identified as being strongly affected by stagnation. Evaluation of the transport to and from the basin shows that the Mediterranean is a crossroad of airstreams where air enters mainly from the northwest and continues in two separate airstreams: one turns towards southwest, passing over North Africa into the trade wind zone while the other one continues northeastwards through Central Asia.

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