Rain Relations Inferred from Microphysical Data in TOGA COARE and Their Use to Test a Rain-Profiling Method from Radar Measurements at Ku-Band

Abstract The first part of this paper is dedicated to establishing relations among rain-integrated parameters representative of west Pacific precipitation. This is achieved by using airborne microphysical data gathered within a rain event on 6 February 1993 during the Tropical Ocean and Global Atmosphere Coupled Ocean–Atmosphere Response Experiment (TOGA COARE). The relations between the rain rate R, the reflectivity factor Z, and the attenuation coefficient K are calculated for moderate to heavy precipitation at 13.8 GHz. They give twice as much attenuation for a given Z than the relations obtained for an exponential distribution with N0 = 8 × 106 m−4. This effect is related to the large number of small size particles observed in TOGA COARE convective systems. In the second part of the paper, these relations are used to check the reliability of a rain-profiling method applied to ARMAR (airborne radar-mapping radar) observations at 13.8 GHz in the same rain event. This method provides a bulk correction fa...