Capturing and explaining the effects of three-dimensional radiative transfer on cloud evolution with the dynamic TenStream solver

Richard Maier, Fabian Jakub, Fabian Hoffmann, and Bernhard Mayer

Data sets

PALM-LES dataset for evaluating the impact of radiative transfer solvers on shallow cumulus cloud development Richard Maier et al. https://doi.org/10.57970/np5r3-t5x93

PALM-LES dataset for evaluating the impact of radiative transfer solvers on shallow cumulus cloud development — Part 2 Richard Maier et al. https://doi.org/10.57970/nzmwf-70w34

Model code and software

PALM model system, version 25.04 PALM https://gitlab.palm-model.org/releases/palm_model_system/-/tree/v25.04

Short summary

Most atmospheric models only use 1D radiation, neglecting any 3D radiative effects. Here, we show that the dynamic TenStream solver provides a computationally efficient way to represent these effects. Like full 3D radiation, it causes daytime clouds to organize into streets, grow larger, and contain more liquid water. We show that this occurs because 3D radiation does not shade cloud updrafts and modifies the surface energy balance, resulting in an increased latent heat flux into the atmosphere.