Through their interaction with solar and thermal infrared radiation, clouds and aerosols have been implicated as two of the greatest sources of uncertainty in climate projections. The EarthCARE (Earth Cloud, Aerosol and Radiation Explorer ) satellite is a joint ESA–JAXA mission designed to provide key new information to tackle this crucial challenge. Launched on 28 May 2024, it carries a Doppler cloud profiling radar (CPR), a high-spectral-resolution atmospheric lidar (ATLID), a multi-spectral imager (MSI), and a three-view broadband radiometer (BBR). CPR is the first radar in space that can measure how fast cloud and precipitation particles are falling in the atmosphere or rising in the cores of thunderstorms, while the ability of ATLID to separately measure the backscatter of particles and air molecules enables it to unambiguously retrieve the all-important profile of the cloud and aerosol extinction. A large number of cloud, aerosol, precipitation, and radiation data products have been produced, some derived from individual EarthCARE instruments and others from the synergy of multiple instruments. This inter-journal special issue presents early scientific results from the satellite, including calibration and validation of EarthCARE data, development of new retrieval algorithms and improvement of existing algorithms, improved understanding of atmospheric properties and processes, evaluation of atmospheric models, and assimilation of EarthCARE data into weather forecast and air quality models.

Review process: This inter-journal special issue co-lists papers of different journals. Thereby, each paper was submitted to 1 particular journal and underwent the regular interactive peer-review process of that journal. Depending on the journal, the peer review was handled by regular members of the editorial board and/or by guest editors designated by the journal’s chief/executive editors.