Exploring vertical motions in convective and stratiform precipitation using spaceborne radar observations: insights from EarthCARE and GPM coincidence dataset

Abstract. With the Doppler velocity (Vd) measurements from the Cloud Profiling Radar (CPR) onboard the Earth Cloud Aerosol and Radiation Explorer (EarthCARE), it has become possible to observe the vertical motions of hydrometeors inside cloud and precipitation globally. While W-band radar observations by CPR can capture clouds and upper-level ice hydrometeors well, Ku- and Ka-band radar observations by the Dual-frequency Precipitation Radar (DPR) onboard the Global Precipitation Measurement (GPM) Core Observatory are more effective under conditions involving rain or moderate-to-heavy ice precipitation, where attenuation and multiple scattering hinder reliable reflectivity measurements by CPR. This study constructed the EarthCARE–GPM coincidence observation dataset and investigated hydrometeor fall speeds and vertical air motion in stratiform and convective precipitation systems by integrating the complementary information from the two radars. Two case studies were conducted for stratiform and convective events, along with statistical analyses of reflectivity and Vd using nearly one year of dataset. CPR well captured ice particle growth in the upper troposphere above −10 °C, while DPR captured the properties of larger hydrometeors in the lower layers, including melting and rain layers. Vd generally increased with decreasing altitude, which is consistent with particle growth inferred from reflectivity observations from both CPR and DPR. Classification into four precipitation types based on echo top heights showed distinct differences in vertical profiles. In deep stratiform cases, Vd reveals slow downward speeds above the melting layer and faster speeds below, consistent with the bright band observed by DPR. Vd in deep convective types indicates faster-falling speed of densely rimed ice particles with high reflectivity and the presence of stronger updrafts and turbulence compared to stratiform cases. These findings indicate that Vd can provide insights into dynamical and microphysical processes inside deep clouds where the quality of reflectivity measurements in W-band deteriorates, and support future development of algorithms for precipitation retrieval and classification using Vd.