Using regional simulations and spatial lidar to study regional cloud variability

Abstract : This work aims to study the clouds' role on regional climate variability. At first order, European climate is driven by large scale circulations. However, clouds are known to have two major radiative effects impacting the surface's temperature: the greenhouse effect and the mask effect. These effects are strongly dependent on macrophysical and microphysical properties of clouds. It is then necessary to consider the vertical distribution of clouds to better understand their impact on regional climate. Since June 2006, A-train observations are available and allow the description of this vertical distribution and of other microphysical properties. However, the sampling is limited. To complete these observations, we use a regional climate model which may allow to extend the period of study and to better understand the link between clouds and surface temperature. In this study we are evaluating our tools and estimating the sampling bias in order to know which scale we can consider with these tools. We are also considering clouds' distribution of the particularly warm winter of 2007