CloudSat Observations of Three-Dimensional Distribution of Cloud Types in Tropical Cyclones

Abstract

The present study investigates the three-dimensional distribution of various cloud types in tropical cyclones formed in the North Indian Ocean surrounding the Indian subcontinent using CloudSat observations of 25 cyclones occurred during 2006–2014. A composite cloud type distribution of cirrus (Ci), altostratus (As), altocumulus, stratocumulus, cumulus, nimbostratus and deep convective (DC) is constructed by combining all the observations as a function of the radial distance from the eye of a cyclone for the first time. The present analysis shows that the peak frequency of occurrence of the DC clouds is 50% at ∼50–100 km radial distance from the cyclone's eye. The Ci clouds are found at altitudes around 13–15 km with a maximum frequency of occurrence of 30% at ∼200 km from the center of the cyclone's eye. The present results suggest that there could be a possible discrepancy in classifying the observed clouds into DC and As clouds using CloudSat observations. All the observations during the study period led to the construction of composite cloud type distribution in the tropical cyclones, which aids in visualizing what type of clouds dominates in which part of the cyclone. Thus, the present study provides a three-dimensional distribution of various clouds embedded in tropical cyclones and associated dynamics, which is very important in better representation of tropical cyclones in numerical weather models and can be used to evaluate the tropical cyclone simulations.