Persistent EarthCARE underflight studies of the ITCZ and organized convection (PERCUSION): Contribution to EarthCARE Validation

Abstract. In May 2024, the Earth Clouds, Aerosols and Radiation Explorer (EarthCARE) satellite was launched. For the first time a satellite combines two active instruments, i.e., the Atmospheric Lidar and the Cloud Profiling Radar, together with two passive instruments, a multi-spectral imager and a broad-band radiometer, on one single spacecraft platform. EarthCARE is thus the most complex satellite mission to date to for collocated aerosol, cloud, radiation and precipitation measurements. To utilize the data collected by the EarthCARE mission to its full extent and to support and quantify the data quality and measurement uncertainty, careful and holistic validation activities are needed. For this purpose, we set up an airborne instrument payload on the German High Altitude and LOng-range research aircraft (HALO), which is similar to the EarthCARE instrumentation. We used this payload during an extensive measurement campaign in summer and fall 2024 in the tropic, sup-tropic and mid- to high-latitudes targeting to validate the EarthCARE measurements and data products early in its commissioning phase. With 33 passes under the EarthCARE satellite during 30 research flights we were able to address target scenes that have been identified by the EarthCARE algorithm developers to be of importance for the validation of the mission, and to assure the retrieval performance under different meteorological conditions and aerosol-cloud situations.