Daily precipitation over southern Africa: A new resource for Climate Studies

This paper describes a new high-resolution multiplatform mullisensor satellite rainfall product for southern Africa covering the period 1993-2002. The microwave infrared rainfall algorithm (MIRA) employed to generate the rainfall estimates combines high spatial and temporal resolution Meteosat infrared data with infrequent Special Sensor Microwave Imager (SSM/I) overpasses. A transfer function relating Meteosat thermal infrared cloud brightness temperatures to SSM/I rainfall estimates is derived using collocated data from the two instruments and then applied to the full coverage of the Meteosat data. An extensive continental-scale validation against synoptic station data of both the daily MIRA precipitation product and a normalized geostationary IR-only Geostationary Operational Environmental Satellite (GOES) precipitation index (GPI) demonstrates a consistent advantage using the Former over the latter for rain delineation. Potential uses for the resulting high-resolution daily rainfall dataset are discussed.