EARTHCARE+ INNOVATION – OBS3RVE

Obs3RvE (Optimising 3D RT EarthCARE product using geostationary observations and AI) proposes an innovative approach towards more accurate quantification of the 3D radiative effects of clouds and their impact on climate, utilising the observations of EarthCARE and MTG missions with AI tools. The results of Obs3RvE will also aim to extend the contribution of the EarthCARE data on solar energy applications, a scientific domain beyond the mission primary objectives.

EarthCARE mission provides 3D radiative transfer (RT) calculations to address the 3D radiative effects of clouds, which is already a big step beyond the state-of-the-art for Earth Observation. These products utilize constructed 3D cloud scenes, combining top-of-the-atmosphere (TOA) 2D observations with vertical profiles of aerosols and clouds along the satellite track. The vertical information of the off-track pixels is deduced from the nadir pixel profiles that present similar radiative properties. Although the uncertainties introduced by this approximation have not been extensively tested yet, this technique may fail when e.g. the off-track clouds are not observed in the nadir profiles (Qu et al., 2023).

Obs3RvE proposes a different methodology for constructing the 3D scenes of EarthCARE, where the missing vertical information of the off-nadir pixels is provided by a Machine Learning (ML) algorithm, trained to derive the vertical structure for all the pixels in the 3D atmospheric scene, using the corresponding 2D radiances at the top of the scene, combined with the vertical structure provided for the nadir track.

The proposed study will produce two innovative 3D products:

• EarthCARE 3D product: 3D scenes of cloud types and cloud microphysical properties along the EarthCARE track
• MTG 3D product: high-temporal-resolution 3D scenes of cloud types and cloud microphysical properties for the MTG observations

These products will be validated with ground-based and airborne observations of cloud properties, as well as with radiation measurements at aircraft level, in Europe and in the Atlantic Ocean (from the ORCESTRA/PERCUSION EarthCARE Cal/Val campaign).

The EarthCARE 3D product is expected to have a high impact on decreasing the uncertainty of the cloud radiative impact on climate, (also) due to its global coverage. The MTG 3D product will be used for assessing the cloud impact on solar radiation/energy applications, due to its high-temporal resolution.

Moreover, Obs3RvE will be coordinated with the projects ESA/EU-CERTAINTY, ESA-AIRSENSE and EarthCARE DISC, through the participation of the Obs3RvE team members in the activities of the respective projects.