The importance of realistic surface radiation in cloud-resolving models

Clouds, radiation, and the Earth’s surface closely interact. Properly representing these interactions is crucial for accurate predictions of weather, climate, and renewable energy production. Radiative transfer can be simulated accurately in 3D or simplified in the vertical direction only (1D) to reduce costs. In this thesis, we investigated how the differences between 1D and 3D radiative transfer impact clouds. We find that simulated clouds are bigger and wetter when using 3D radiation. However, the total amount of radiation at the surface is unchanged. We show that the differences in clouds are driven by the position of the cloud shadows and the horizontal distribution of scattered radiation. Furthermore, we show that capturing only the probability distribution of radiation is not sufficient, the spatial patterns are at least as important. Lastly, we show that the model used in this thesis captures the physics of convective clouds in line with an operational weather model.