Variations of Ice Microphysical Properties in Tropical MCS Using Cloud In-Situ Data and Corresponding Radar Reflectivity Profiles
Résumé
Mesoscale convective systems (MCS) can last several hours or more and affect human societies in different ways. In order to predict and identify hazardous weather (e. g. in view of aviation safety) linked to MCS, numerical weather forecast and active/passive remote sensing products are currently the most useful tools. A major obstacle to increasing the accuracy of those tools is the fact that cumulonimbus clouds in MCS are composed of liquid droplets and ice hydrometeors (ice crystals); the latter have complex shapes based on diffusional growth, aggregation, and riming, which complicates the interpretation of remote sensing products and increases the uncertainties in numerical weather forecast. In this context, the study presented here investigates the properties of ice hydrometeors in MCS as a function of temperature and horizontal distance from the convective core. For this purpose, ice hydrometeor images, bulk TWC, and simultaneously measured radar reflectivity factors from three airborne campaigns in tropical MCS have been used. The underlying scope of producing these results is to improve the retrieval of MCS microphysical properties from satellite products and also improve cloud parameterizations in numerical weather prediction models.