Validation and applications of a realtime global precipitation analysis

A series of validation statistics are presented from a operational global, minimum 3-hourly updating precipitation analysis. The technique was developed at the Naval Research Laboratory (NRL) for use in numerical weather prediction (NWP) model data assimilation and now casting operations. The technique is an adaptive statistical/hybrid technique which incorporates data from all current operational infrared-based geostationary satellites and from all (currently) available low-Earth orbiting microwave-based sensors, the Special Sensor Microwave Imager (SSMI), the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI), and the Advanced Microwave Sounding Unit (AMSU-B). Knowledge of the rain estimation error statistics are needed in order to properly utilize precipitation observations in NWP variational assimilation techniques. Validation statistics are presented from comparisons with operationally supported raingauge networks in Australia and Korea in a two-dimensional fashion, where the spatial and temporal dimensions are each individually varied.