Spatial and Seasonal Variability of Clouds over the South-West Indian Ocean Based on DARDAR v2 Products

We will present a characterization of the spatial and the seasonal variability of clouds over the Indian Ocean based on satellite observations. CALIPSO and CLOUDSAT measurements are processed in synergy with a variational algorithm to retrieve the DARDAR (raDAR/liDAR) products providing a cloud thermodynamic classification (ice, warm liquid, supercooled liquid, supercooled water and ice mixed, cold rain, warm rain, drizzle…). In this study, we first investigate the occurrence frequency of clouds on subtropical and tropical areas from 5°S to 60°S and from 35°E to 95°E between 2007 and 2010. We focus on the southwestern Indian Ocean (SWIO) where satellite measurements are essential for observing tropical convective systems, as these are developing in remote oceanic regions with less conventional observations. Convective systems, cyclonic or non-cyclonic, can generate heavy precipitation in the emerging lands. This study should improve our understanding of precipitating clouds in SWIO. The DARDAR target classification, the CALIPSO lidar backscatter coefficient, the CLOUDSAT radar reflectivity and even complementary satellites observations will be used to develop detection criteria for different cloud types (cirrus, cumulus...) and properties (mode of convection, precipitation…).