Climate variability of the Med region detected by ERA-40 surface water vapour data

An analysis of the climate variability of the Mediterranean region is performed by using ERA-40 surface water vapour data. Previousstudies show that this parameter may be used as an index for detecting the prevalence of weather condition more related to the tropicalaspects of the Mediterranean area. The ECMWF project ERA-40 provides the long time series of values used in this investigation. Theresults are examined according to some climate indices and to the main pattern of variability observed in the circulation of theMediterranean Sea.