The Performance of the EarthCARE CPR in Marine Stratiform Clouds

Marine stratiform clouds play a critical role in the global radiation budget and hydrological cycle, and thus in climate and climate change. Their considerable influence on Earth's climate can be attributed to their vast horizontal coverage, their ability to strongly reflect incoming shortwave radiation and their regulating effect on the marine boundary layer structure through drizzle and turbulence production. Here, we examine the performance of the EarthCARE 94‐GHz Doppler Cloud Profiling Radar (CPR) in: i) detecting these clouds and their boundaries, ii) improving drizzle rain rate retrievals through the use of the CPR Doppler velocity measurements. The evaluation is conducted using a state‐of‐the‐art simulator that emulates the CPR radar reflectivity and mean Doppler velocity measurements. Observations from the Atmospheric Radiation Measurements (ARM) Mobile Facility at Azores and Marine ARM GPCI Investigation of Clouds are used as input to the CPR simulator to provide a healthy sample of realistic marine stratus scenes. The ground‐based observations are treated as the “truth” and are compared to the simulated EarthCARE CPR observations and statistics from CloudSat observations from the same geographical locations. The impact of the surface echo return, sensitivity and range resolution in the detection of marine stratiform clouds are discussed.