| 01 Oct 2026
Global climatology of vertical cloud motion observed by EarthCARE/CPR: Cloud-type dependence with link to microphysics
Abstract. Nadir-pointing cloud-radar Doppler velocity (Vd) quantifies the reflectivity-weighted vertical motion of hydrometeors by combining sedimentation and vertical air motion. Thus, it provides an observational constraint on cloud microphysical–dynamical processes. However, as spaceborne Doppler measurements have only recently become available, its global climatology remains poorly documented. This study utilized EarthCARE Cloud Profiling Radar observations to establish the global climatology of Vd and evaluate its association with temperature, reflectivity, and cloud type. Quality-controlled Vd samples were analyzed after classifying cloud layers into five types based on the cloud-top temperature and column-maximum reflectivity. Results indicate that Vd is predominantly downward, consistent with hydrometeor sedimentation, and that the downward motion becomes faster at warmer temperatures. Below the melting layer, Vd varies among cloud types, even at comparable reflectivities. Further, warm precipitating clouds exhibited faster downward Vd than non-precipitating warm clouds, whereas precipitation originating from cold cloud layers demonstrated even faster downward Vd. These cloud-type differences indicate that Vd describes precipitation pathways and vertical air motion, which are not captured by reflectivity alone. Geographical patterns of mean Vd display faster downward velocities over tropical convective regions dominated by precipitating clouds, but much weaker downward velocities over subtropical stratocumulus regions dominated by non-precipitating warm clouds. Additionally, the fractional occurrences of substantially positive Vd highlight upward particle motion signatures obscured in the mean fields, particularly in strongly precipitating cold clouds in the tropics. Therefore, spaceborne Doppler measurements provide a benchmark for evaluating cloud microphysics, precipitation formation, and convective transport in global models.
Competing interests: At least one of the (co-)authors is a guest member of the editorial board of Atmospheric Chemistry and Physics for the special issue “Early results from EarthCARE (AMT/ACP/GMD inter-journal SI)”.
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