The EarthCARE (Earth Cloud, Aerosol and Radiation Explorer)satellite was launched in May 2024 as a joint ESA-JAXA mission for observing the three-dimensional structure of cloud, aerosol and radiation, with the goal on improving our characterisation of clouds and aerosols, and their radiative effects on the climate. The satellite holds 4 sensors; Cloud Profiling Radar (CPR) and ATmospheric LIDar (ATLID) are active sensors, whereas MultiSpectral Imager (MSI) and BroadBand Radiometer (BBR) are passive instruments. With 4 instruments, EarthCARE provides both microphysical and radiation properties of cloud/aerosol, revealing their connection to convective dynamics. Particularly exciting for the scientific community is also the unprecedented ability to make observations of the vertical cloud motion from space by measuring the doppler velocity with CPR, as well as to more accurately classify aerosol and cloud particle types with ATLID.
These new observations have tangible benefits for the climate modelling community by reducing the uncertainty of microphysical processes in climate models. This is why the CMIP 2026 Community Workshop had a dedicated side session on the EarthCARE mission, showcasing early scientific results and the demonstrating the new EarthCARE satellite signal simulator for climate model evaluation.
Improving climate models with EarthCARE
EarthCARE observations are expected to help constrain cloud and aerosol uncertainties in climate models. Certainly, early comparisons of EarthCARE with global storm-resolving climate models show how the observations challenge the way cloud tuning is currently done in models. For example, the evaluation of vertical motion of cloud particles in MIROC6 (the sixth version of Model for Interdisciplinary Research on Climate) revealed error compensations at a process level, which would not have been identified without EarthCARE. Comparisons of satellite simulations using NICAM (Nonhydrostatic ICosahedral Atmospheric Model) with EarthCARE observations also revealed good model representation of the overall vertical structures, with some biases in convective regions. Scientists participating in the EarthCARE-ORCESTRA Model Intercomparison Project (ECOMIP) have developed methods which endeavours to improve models by exploiting EarthCARE observations. All these examples have showcased how EarthCARE helps advance global models towards those generating “right answers for right reasons” with a lesser extent of error compensation.
Comparing like with like
The second half of the learning lab demonstrated the newly developed EarthCARE satellite simulators within COSP2 (CFMIP Observation Simulator Package version 2). A new lidar simulator accommodating ATLID and a doppler velocity simulator accommodating CPR were introduced, and early results of using these simulators to evaluate climate models were presented. The demonstration elicited a very positive response from those attending the session, and the climate modelling community are excited about EarthCARE’s unprecedented capabilities for advancing climate model development.
