Vertical motions in clouds from EarthCare satellite and a global storm-resolving modeling

Abstract

Understanding vertical motions in clouds is essential for improving weather and climate models but remains challenging due to limited observations. The newly launched EarthCARE satellite with a Doppler radar now provides global measurements of how fast particles fall through clouds, offering a way to estimate vertical air movements. In this study, we provide an initial assessment of EarthCARE’s Doppler radar observations by comparing them with high-resolution global simulations using NICAM and a satellite simulator. We analyze two representative cases of frontal and convective precipitation to examine how vertical motions influence the relationship between radar reflectivity and the fall speed of ice hydrometeors, and to identify potential discrepancies between observations and simulations. The results show that the simulations reproduce the overall vertical structures observed by EarthCARE, while differences in Doppler velocity, particularly in convective regions, indicate biases in simulations and uncertainties in the observations. Nevertheless, these complementary perspectives reveal EarthCARE’s capability to provide physically consistent information on hydrometeor vertical motions and demonstrate its potential to constrain and refine the representation of cloud microphysics and dynamics in global weather and climate simulations.