Quantifying three-dimensional radiative transfer effects of clouds using EarthCARE observations and collocated airborne data

The effect of clouds on radiation remains a critical source of uncertainty in climate and weather prediction models. Moreover, the 3D structure of the clouds, including horizontal heterogeneity along with cloud vertical placement, further affects the radiation fields. Herein we utilize the 3D cloud scenes provided by EarthCARE to quantify the effect of the cloud 3D structure on radiation. Monte Carlo radiative transfer (RT) simulations from the MYSTIC/libRadtran model are employed to calculate the 1D vs 3D radiation fields. Airborne observations are also utilized, acquired during the ORCESTRA/PERCUSION EarthCARE Cal/Val campaign in the tropical Atlantic.

Simulated top-of-atmosphere 1D and 3D radiances and irradiances are compared with EarthCARE Broadband Radiometer (BBR) observations, along with collocated radiation observations from the Munich Aerosol Cloud Scanner (specMACS) onboard the HALO aircraft during the ORCESTRA/PERCUSION campaign. The 1D vs 3D RT simulations are performed to investigate the importance of the 3D cloud structure on the cloud radiation fields, for different types of clouds.

This analysis is part of the Obs3RvE EarthCARE+ project, which aims to develop new realistic 3D cloud scenes, combining EarthCARE and Meteosat Third Generation (MTG) observations, employing machine learning tools. These new 3D cloud scenes are expected to improve estimates of the cloud radiative effect from EarthCARE, as well as extend its suite of products to solar energy applications.

 

Acknowledgements:

This work has been financially supported by the Obs3RvE (Optimising 3D RT Earthcare product using geostationary observations and AI) project, funded from the European Space Agency under Contract No. 4000147848/25/I/AG, the PANGEA4CalVal project (Grant Agreement 101079201) funded by the European Union , the CERTAINTY project (Grant Agreement 101137680) funded by Horizon Europe program, the EarthCARE DISC project, funded by the European Space Agency under Contract No. 4000144997/24/I-NS and the AIRSENSE (Aerosol and aerosol cloud Interaction from Remote SENSing Enhancement) project, funded from the European Space Agency under Contract No. 4000142902/23/I-NS. It is also based upon work from COST Action EARLICOST, CA24135, supported by COST (European Cooperation in Science and Technology). DK, ΑΤ and SK would like to acknowledge COST Action HARMONIA (International network for harmonization of atmospheric aerosol retrievals from ground-based photometers), CA21119, supported by COST (European Cooperation in Science and Technology).