CR 23:195-215 (2003)  -  doi:10.3354/cr023195

Analysis of wintertime atmospheric moisture transport and its variability over southern Europe in the NCEP Reanalyses

Jesús Fernández1,*, Jon Sáenz1, Eduardo Zorita2

1Depto. Física Aplicada II, Universidad del País Vasco, Apdo. 644, 48080 Bilbao, Spain
2GKSS Research Centre, Institute of Hydrophysics, 21502 Geesthacht, Germany

ABSTRACT: A common analysis of instrumental monthly precipitation records and 6 h meteorological Reanalysis from the National Centers for Environmental Prediction (NCEP) was performed to diagnose the main modes of tropospheric, vertically integrated moisture transport over the Mediterranean basin and southern Europe. The moisture transport and its variability at each grid point and at the boundaries of the domain were quantified. Quantities such as the standard deviation of filtered geopotential height, one-point correlation maps and Z300-Z500 and Z500-Z700 thicknesses, related to the intensity and typical paths of baroclinic disturbances, were also computed to help in the interpretation of the results. It is clear that the leading mode of Mediterranean precipitation has its roots in the dynamics of the Atlantic storm track and the associated moisture transports. The second mode represents the internal redistribution of moisture inside the Mediterranean basin. Moisture is supplied to the atmosphere in the western Mediterranean, and this moisture is transported and precipitates over the eastern Mediterranean (mainly Turkey and Greece). Finally, the third mode depends on the role of European topography as a blocking factor for westerly moisture transport advected from the North Atlantic region.

KEY WORDS: Mediterranean · Southern Europe · Precipitation · Variability · Winter · Moisture

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