Precipitation retrieval and nowcasting from satellite within project “NOWCASTING-PROSA”of the Italian Space Agency

Three years ago, the Italian SpaceAgency (ASI), in agreement with the Italian Department for Civil Protection (DPC), funded a project finalized to the nowcasting of the intense storms that produce floods over the Italian peninsula. A goal of this project was the development of algorithms for the estimation of precipitation from satellite data and, consequently, of products that may be used for issuing meteorological warnings on the basis of satellite observations (Italian acronym: PROSA). The project, which is still running, is coordinated by Carlo Gavazzi Space which is responsible both for the system engineering/quality aspects and for the coordination of the pre-operational activities, while it is scientifically coordinated by the CNR-ISAC Institute which is responsible for the harmonization of the various products that are generated by the scientific partners. Specifically, these precipitation products are generated according to algorithms that are developed by CNR-ISAC and the Universities of Ferrara and Roma in collaboration with the international community, and that exploit the following satellites and instruments: - SSM/I, SSMIS, and AMSR-E conically-scanning microwave (MW) radiometers onboard low Earth orbit (LEO) DMSP and EOS-Aqua satellites; - AMSU-A and AMSU-B / MHS cross-track scanning MW radiometer couples onboard NOAA and MetOp LEO operational satellites; - SEVIRI visible-infrared (VIS-IR) imager onboard the European geosynchronous MSG satellite. The specific products of PROSA are: - Instantaneous precipitation rate at ground from MW radiometer observations, using both physical (Bayesian) and neural network (NN) algorithms; - Instantaneous precipitation at ground from combined MW/VIS-IR observations, using NN, blending and morphing algorithms; - Cumulated precipitation at ground using blending and morphing approaches; - Nowcasted precipitation at ground using hybrid and morphing approaches. While precipitation products are generated in a preoperational fashion, with a delay of few minutes to few hours from observation depending on product and satellite data access, the emphasis is on near-real-time applications – as requested by DPC. Here, we will present and discuss the basic precipitation algorithms, products and processing schemes that are being developed within this project.