Global multiscale evaluation of satellite passive microwave retrieval of precipitation 1 during the TRMM and GPM eras : effective resolution and regional diagnostics for 2 future algorithm development

10 The constellation of space-borne passive microwave (MW) sensors, coordinated under 11 the framework of the Precipitation Measurement Missions international agreement, 12 continuously produces observations of clouds and precipitation all over the globe. The Goddard 13 Profiling Algorithm (GPROF) is designed to infer the instantaneous surface precipitation rate 14 from the measured MW radiances. The last version of the algorithm (GPROF-2014) -product 15 of more than 20 years of algorithmic development, validation and improvement -is currently 16 used to estimate precipitation rates from the microwave imager GMI onboard the GPM core 17 satellite. The previous version of the algorithm (GPROF-2010) was used with the microwave 18 imager TMI onboard TRMM. In this paper, TMI-GPROF-2010 estimates and GMI-GPROF19 2014 estimates are compared with coincident active measurements from the Precipitation Radar 20 onboard TRMM and the Dual-frequency Precipitation Radar onboard GPM, considered as 21 reference products. The objective is to assess the improvement of the GPM era microwave 22 estimates relatively to the TRMM era estimates and diagnose regions where continuous 23