The precipitation field over Calabria: Large-scale correlations

In this paper we analyze the variability of the precipitation field over Calabria for the period 1948-1990 and its correlation with large-scale flow. Precipitation data are from “Istituto Mareografico ed Idrografico” database, have a monthly basis and cover the period 1921-1990. It is shown that precipitation is concentrated in the cold semester, from October to April, and that there is a large annual-to-annual variability. After studying correlation between precipitation and North Atlantic Oscillation (NAO), rainfall variability is further discussed by relating the precipitation standardized anomaly index to surface pressure, 500 hPa geopotential height and sea surface temperature. These dataset are derived from NCAR reanalysis project, and cover the 1948-2002 period. Due to temporal coverage of our databases the analysis is limited to 1948-1990. While a weaker correlation with NAO emerges, compared to other areas of the Mediterranean basin, precipitation over Calabria shows an interesting correlation with another dipolar structure located further East. This correlation is mainly related to the strength of Azores anticyclone over the Mediterranean area in the cold season and to the oscillation of Siberian high