First insights into deep convection by the Doppler velocity measurements of the EarthCARE Cloud Profiling Radar

Abstract

Convective updrafts and downdrafts play a vital role in Earth's energy and water cycles by modulating vertical energy and moisture transport and shaping precipitation patterns. Despite their importance, the characteristics of convective motions and their relationship to the near-storm environment remain poorly constrained by observations. Doppler radars, in principle, are able to measure the vertical air motion within clouds, thus providing critical insight into convective dynamics and enabling estimates of convective mass flux. The payload of the recently launched EarthCARE satellite mission includes a 94 GHz Cloud Profiling Radar (CPR) with Doppler capability. In this study, we present first-light CPR Doppler velocity observations in deep convective clouds. These early examples offer a first glimpse into the dynamic nature of cloud systems. The narrow footprint of the CPR helps reduce the impact of multiple scattering and non-uniform beam filling (NUBF) on the Doppler velocity measurements. However, the instrument's low Nyquist velocity presents a significant challenge for recovering the true Doppler velocity profiles in deep convective systems. The CPR Doppler velocity observations are expected to challenge traditional methodologies for identifying deep convective cores, which typically rely on reflectivity-based thresholds. We showcase examples that demonstrate the synergy between CPR Doppler velocity measurements and geostationary satellite observations, illustrating how their combined use can help capture the evolution of the convective lifecycle. These results align with EarthCARE's broader mission objectives and highlight the potential of spaceborne Doppler radars to significantly advance our understanding of cloud dynamics and convection in the climate system.