Atmospheric precipitation analysis using both disdrometric and satellite data for desertificaton studies.

In the study of desertification processes, an important role is obviously played by the atmospheric precipitation investigation. The Italian project RIADE (Ricerca Integrata per l’Applicazione di tecnologie e processi innovativi per la lotta alla Desertificazione), has been setup to study the atmospheric precipitation in southern Italy and islands (Sicily and Sardinia), that can be potentially affected by desertification phenomena. A comparison with observation from different sensors having different resolution has been realized. The analysis has been conducted in a quantitative way using the new generation X-band microwave raingage-disdrometer named PLUDIX, installed in three different Italian sites. PLUDIX data have been used both for rainfall events detection and for a climatological analysis of the rain events. Moreover, through rainfall rate (R) and drop size distribution (DSD) parameters estimation, the instrument has allowed a microphysical characterization of rain at the ground and the discrimination between convective and stratiform events. We also used satellite data from Meteosat-7, SSMI (Special Sensor Microwave Imager) and MODIS (Moderate Resolution Imaging Spectro-radiometer) for a qualitative analysis of the precipitation systems. Because of the different spatial scale of the disdrometer and satellites, satellite data was used for the temporal scale analysis and for the cloud characterization (quality, type and structure of the rain clouds) of the selected events, as well as for the comprehension of the spatial extension of each rain event (genesis and evolution). We have also linked the observed events to the corresponding conceptual models in the Mediterranean area.