This session will address interactions between solar and terrestrial radiation and cloud and aerosol particles in the atmosphere from the point of view of numerical weather prediction (NWP) and climate modelling. The increasing need for accurate radiation outputs for the growing renewable energy sector will also be addressed. Special attention will be paid to the validation of NWP radiation outputs by using ground-based and satellite measurements of fluxes.

This session is expected to focus on the above points and to gather presentations and posters on the following topics:

• General aspects of radiation and microphysics parametrizations and their interactions in NWP models
• Obtaining the inherent optical properties of cloud, precipitation and aerosol particles for the use of NWP models
• Time, space and spectral resolution of the radiation parametrizations required by the models from mesoscale to global circulation
• Evaluation of radiation and cloud output from NWP models; use of shortwave radiation measurements for cloud verification
• Handling of radiative transfer in clear and cloudy atmospheric boundary layers; three-dimensional aspects and complex topography; radiative properties of the underlying surface

Invited keynote speaker:

Petri Räisänen: "Radiative transfer in atmospheric models-why do we still have to work on it?"