Relationship between ice supersaturation and ice microphysics inferred from CloudSat, CALIPSO and AIRS

Super saturation of ice clouds was investigated by using CloudSat, CALIPSO and AIRS on Aqua. Global distributions of relative humidity and temperature were first retrieved by using Ishimoto 2009 AIRS algorithm that used 110 channels and 46 channels for temperature and humidity retrievals, respectively. Retrievals have been conducted between 600hPa and 200hPa and also above clouds when cloud top height was below 800hPa. We relied on the information of clouds, i.e., cloud location and ice water content, from CloudSat radar and CALIOP lidar. The water vapor density from AIRS had been sampled along CloudSat and CALIPSO tracks in order to retrieve relative humidity in the vicinity of ice clouds. Relative humidity when ice formation occurred was estimated by using ice water content and the water vapor density near ice clouds.