Ground-based scanning Ka-band cloud radar observations for validation of EarthCARE Cloud Profiling Radar (CPR)

The National Research Institute for Earth Science and Disaster Resilience owns five scanning Ka-band cloud radars. Using these radars, we are planning to validate the cloud profiling radar (CPR) of the EarthCARE satellite. The EarthCARE CPR only observes along the line directly under the satellite path and has a return period of about 25 days. Therefore, we will facilitate the comparison by collecting data from what we can consider to be the similar region as the EarthCARE path. Statistical validation will be performed by creating a Contoured Frequency by Altitude/Temperature Diagram (CFAD/CFTD) and comparing the distributions. Both case and relatively long-term comparisons are possible. On the other hand, although the opportunity is rare, it is possible to compare the vertical profiles at the intersection with the vertical (RHI) observations of the ground-based radar if the EarthCARE path comes within the range of the ground-based cloud radar with the observation range of 30 km. Three-dimensional observations using Plan Position Indicator (PPI) scans can be used to generate data on the Cartesian grid (CAPPI data). From this CAPPI data, it is possible to create a vertical cross section along the path of the EarthCARE satellite. Because of the limited number of elevation angles, the comparison is relatively coarse in the vertical direction. Since this observation is not done in the vertical direction, only radar reflectivity is used for comparison, not Doppler velocity. Other methods of verifying liquid water contents using cloud radar and microwave radiometer are also under consideration.