C³IEL : Cluster for Climate and Cloud Imaging of Evolution and Lightning, an innovative way to observe clouds and their environment

The French-Israeli C³IEL (Cluster for Climate and Cloud Imaging of Evolution and Lightning) is an innovative mission currently in the pre-formulation stage that will provide unprecedented new insights to outstanding climate questions. This demonstration mission, mainly focused on convective clouds, aims at characterizing dynamically the clouds and the interactions with their environment at a high spatial and temporal resolutions of the scales of the individual convective updrafts. The C³IEL coordinated train of nano-satellites will carry visible cameras measuring at a spatial resolution of ~20 meters, near-infrared imagers measuring in and near the water vapor absorption bands, and optical lightning sensors and photometers. The observations of these space-borne sensors will simultaneously document the vertical cloud development retrieved by a stereoscopic method, the lightning activity and the distribution of water vapor at a high resolution by exploiting the multi-angle measurements for application of tomography methods.

The scientific objectives of the C³IEL mission will be introduced, and the nano-satellite train configuration, the observational strategy and the different sensors of the mission will be discussed. Finally, we will introduce the observations and products of the C³IEL mission that will give new understanding of the redistribution of the energy and water vapor in the atmosphere, and of the relation between storm vigor and frequency of lightning activity.