Climate models predict an increase in the Earth’s surface temperature between 2 and 5 K for a doubling of the atmospheric carbon dioxide concentration. This uncertainty strongly depends on cloud feedbacks, which suffer from enduring biases affecting the representation of cloud processes in climate models. To tackle this problem, a more robust physical understanding of the coupling between clouds, mixing processes and the large-scale circulation is necessary. Likewise, to understand the implications of a given sensitivity an understanding of how circulations respond to warming, and the role of clouds therein, remains paramount. Together these constitute a Grand Challenge of the World Climate Research Programme.

Satellite remote sensing, particularly from active sensors, is increasingly serving as the observational foundation for studying these questions, and evaluating ideas developed with the help of a variety of modelling and theoretical tools. Dedicated field studies and long-term ground-based measurements are often used to advance our ability to interpret satellite remote sensing and models. As the community moves into the second generation of active satellite borne remote sensing of clouds and precipitation this session endeavors to take stock of what we have learned, what an exciting second generation of measurements -- from EarthCARE to AEOLUS to GPM -- stands to teach us, how they can be linked to theoretical developments in the field, and how prospects on the drawing board for a third generation of such measurements (such as the proposed CNES MESCAL & ESA Qsat missions) might inform understanding of cloud-circulation coupling.