Comparison of TRMM precipitation radar with NEXRAD and in-situ rain gauges in central and South Florida

Abstract

The purpose of this paper is to use various mathematical methods for processing precipitation data and presenting an independent ground-based measurement of rainfall rate and accumulation for calibration of TRMM Precipitation Radar (PR). Reflectivity data from the Melbourne National Weather Service WSR-88D Next generation Radar (NEXRAD) were collocated in time and space with gauge data located in Central and South Florida. The corresponding NEXRAD reflectivity (Z) and gauge rain rates (R) were matched. Different regression methods were tested to find a suitable Z-R relationship for convective and stratiform rainfall for Melbourne NEXRAD. This Z-R relationship was used to produce instantaneous rain rate maps, and monthly rain accumulation maps. This resulted in a large coverage area for comparison with TRMM PR rain products; instantaneous rain rate, and average monthly rain rate. Statistics are presented for three months operations during August and September 1998, and June 1999.