Clouds play a dominant role in the climate system. To a large extend, their interaction with solar and infrared radiation determines the atmospheric radiation balance. One of the crucial questions in the study of climate change is how the clouds will respond to global warming, and consequently, how this will alter the radiation balance.
This project deals with the observational part of the problem: can we measure the cloud properties will enough to determine their impact on the atmospheric radiation with sufficient accuracy? To this end, multi-sensor techniques, based on ground-based cloud radar, lidar and microwave radiometry, will be used to retrieve cloud microphysical properties and to calculate the radiative transfer through the clouds. With ground-based and space-borne radiation observations of the same cloud scene, the accuracy of the calculated radiation will be assessed. Different radiation transfer models will be used and compared. This project will be carried with other ITaRS partners.