| 05 Feb 2026
Characteristics of tropical clouds with strong updrafts revealed by Doppler velocity measurements from EarthCARE/CPR
Abstract. Updrafts within clouds are important for the climate system, yet global assessments have traditionally relied on indirect proxies. The EarthCARE satellite's 94 GHz Cloud Profiling Radar (CPR) provides the first global, spaceborne Doppler velocity (Vd) profiles of clouds, enabling direct constraints on convective updraft intensity beyond proxy-based diagnostics. We analyze CPR cloud-property products over the tropics and extract convectively driven columns. We define MaxVd as the maximum upward Vd within the subfreezing portion of each column. Columns with MaxVd > 2.5 m s⁻¹ are classified as strong-updraft (SU) columns. They exhibit systematically higher echo-top heights at 0 and 10 dBZ than weaker-updraft columns, linking microphysics to dynamics. The probability of SU occurrence strongly depends on the separation between the cloud top and the 0 dBZ echo top, defined as ΔH. A small ΔH robustly identifies SU, including relatively low-topped systems. Spatiotemporally, SU occurrence is enhanced over land, with notably higher values at the 14:00 local-time overpass than at 02:00. In contrast, oceanic regions have a smaller SU fraction and exhibit a weaker difference between the two overpass times. These SU enhancements primarily reflect a shift toward horizontally compact, small-ΔH systems rather than higher cloud tops alone. Doppler folding preferentially occurs in small-ΔH structures, with maxima during the continental afternoon, providing a qualitative tracer of extreme updrafts. The combined constraints from Doppler-derived updraft intensity and echo structure offer a process-oriented benchmark for evaluating the coupling between convective dynamics and microphysics in numerical models.
The paper investigates the characteristics of tropical convective clouds in light of the novel Doppler velocity measurements from EarthCARE/CPR. The topic is of great interest for the cloud dynamics community. Results are well presented and introduce the first global climatology of convective motions (of course with the limitations of the CPR measurements). I would suggest a clear statement in the abstract that the SU (strong convection) cases actually are not surely representing the strongest updrafts measured by EC (which viceversa will corresponds to the folded cases). This has to come clear even to readers who are not EC-CPR experts. I have then some specific comments.
1) "We exploit EarthCARE’s Doppler capability to analyze vertical velocity w even in clouds with weak radar echoes". Not sure what the authors mean. What Reflectivities are we talking about? I would avoid vague statements.
2) Line154-155: "To correct for ε_pointing, we apply a bias correction based on the assumption that the Doppler velocity averaged horizontally over 100 km at the surface is zero ". I am not so sure about this. Ocean surface is fine for Doppler calibration but not the same can be said for the land (see Bernat et al., 2025 paper on mispointing).
3) Folding and averaging of Vd: it is not clear to me what has been done. The authors mention "first-pass dealiasing applied following Hagihara et al. ", maybe it would be good to include details here. Afterwards, how is the averaging of Vd over 3 km windows performed?(are these simple Vd averages?Are you averaging in the lag-1 correlation space)? What happens if there are multiple scattering contaminated pixels in the averaging region?
4) Definition of MaxVd: "We then define MaxVd, the column-maximum Doppler velocity, as the largest Vd within the portion of the 3-km– and 200-m–averaged profile that is colder than 273.15 K for columns that are not flagged as folded." Not sure this is the right definition. I suppose you are searching for a maximum in the entire column among the the 3-km– and 200-m–averaged Vd values?
5) "The main results are insensitive to reasonable variations in these parameters". A little bit too vague. Can we be more specific? I suppose that if we start averaging too much we may end up with serious issues. Also if the averaging has been done in the velocity space, aliasing issues can come into play (and tend to bias averaged velocities towards zero values)
6) "the native 1 km × 200 m Doppler-velocity field": I thought the native was 500m x 100m
7) Fig1:
a) Fig1c: I do not see any flagging to multiple scattering. I would expect there is something around pixel 500.
b) Panel d: difference between orange and blue line. Of course going to 3 km scale significantly reduce the Vd intensity (convective cores are typically much smaller than 3 km). Again if averaging is done in the Vd space this may be an "artificial" effect due to folding. Indeed I strongly disagree with the statement at line 218-219 "while preserving the location and relative magnitude of embedded updraft cores" (in fact the difference between the blue and orange line shows exactly that!). All the dsicussion at line 235-238 in fact mention that. Airborne measurements are typically representative of averages at much shorter scales!
c)"Grey shading denotes columns flagged as being affected by residual velocity folding": I am surprised not to see any at around index 75.
8) Sect3.2 and after. All Tables and percentages are defined with respect to the number of QC 3-km columns, correct?
This could be improved. In fact in some cases you get percentages up to 9% which is definetely too high!! We would like to know how frequent these convective clouds are (thus with respect to all 3-km columns). Also it is probably better to put together in the same Table results for SU and EU (extreme updraft corresponding to velocity folding, I would introduce some terminology there). I would actually term SU ==> MU (moderate updrafts) and Doppler foldings ==> SU (strong updrafts).
9) Line 601-602: "As a result, we cannot yet directly evaluate echo-top
height climatologies at 20–40 dBZ derived from the TRMM and GPM precipitation radars". Well the Ku-band 20-40 dBZ levels are certainly detected by EC but non-Rayleigh effects are substantially reducing those levels (in addition to attenuation). The recent paper by Chase et al., A Multifrequency Spaceborne Radar Perspective of Deep Convection should be mentioned here.