Cluster analysis of tropical clouds using CloudSat data

The mesoscale patterns of cloud/precipitation radar reflectivity from early CloudSat data are used to identify distinct tropical cloud regimes via a cluster analysis. Five basic cloud regimes are identified, and the geographical distribution of their occurrence frequency is quantified. Although the contemporary MODIS observations show some limitations to CloudSat observations, comparison with traditional passive satellite observations shows that CloudSat describes the major features of the vertical structure of the tropical cloud regimes. Using the monthly mean vertical velocity at 500 hPa as an indicator, the elements of each cloud regime are sorted into different dynamical regimes, and the results demonstrate the links between clouds and the atmospheric circulation.