Assimilating EarthCARE into numerical weather prediction

ESA’s EarthCARE satellite was developed to make a unique set of simultaneous measurements that shed new light on the role that clouds and aerosols play in regulating Earth’s climate. Now, in a remarkable example of a research mission delivering direct practical benefits, global observations from the satellite’s cloud profiling radar are being used operationally by the European Centre for Medium-Range Weather Forecasts (ECMWF) to improve daily weather forecasts – this landmark achievement marks the first time that cloud radar data from space have been assimilated into a global weather forecasting system.

Data assimilation is a complex endeavour. This infographic highlights the main steps involved in assimilating EarthCARE’s cloud profiling radar data in the ECMWF numerical weather predication model to update the current state of the atmosphere, providing initial conditions which ultimately improve the forecast of future weather.

As an example, cloud profiling radar observations shown here are of Typhoon Ragasa over the west Pacific on 21 September 2025, before data assimilation started.

Read full story: A first: EarthCARE cloud data sharpen weather forecasts