Quantification of drizzle fraction using large eddy simulation model output: The multi-purpose of the earthcare simulator

Earth's low altitude, warm, layered clouds play a major role in the climate system, reflecting back a large amount of the incoming shortwave radiation from the Sun. Stratocumulus (Sc) clouds are typical representatives of such type of clouds. They cover vast areas, extensively spreading in horizontal direction, having a considerable impact on the radiation budget. To look into the process of the Sc structure variability and evolution, retrievals of the microscale cloud properties are used. These can be related back to the large scale processes that consequently onset due to a change in the microscale. One of such chain of events is the growth of cloud droplets via process of diffusion until a critical size is achieved, from where process of collisions and coalescense takes over, forming light drizzle drops. This type of feedback could lead to development of pockets of open cells (Stevens et al., 2005), also changing the cloud radiative properties. Drizzle onset process regarding such clouds is of great importance to comprehend the cloud evolution and its impact on the radiation budget. To analyze the consequence chain this microphysical process holds on a large scale, a modified version of the EarthCARE mission Simulator (ECSIM) is used here to ingest cloud scenes from a Large Eddy Simulation (LES) model, represented with microphysical output. Full description of the LES model used is given in Heus et al., 2010. Recreated scenes in ECSIM were used in order to generate realistic observations for ground-based radar instrument.Geoscience & Remote SensingCivil Engineering and Geoscience