Three-dimensional characteristics of polarimetric radar variables and their precipitation-type dependence

The characteristics of cloud microphysics in the precipitation are important for the rainfall estimation in good accuracy from space borne microwave radiometers on TRMM and/or GPM. One of the basic problems is to clarify the differences of cloud microphysical characteristics such as drop size distributions (DSD) in the convective precipitation and in the stratiform precipitation. Identification of hydrometeor above the level of 0°C is also indispensable information for rain retrieval algorithms. From the view of cloud microphysical characteristics, some more classifications are necessary in addition to a simple classification of convective and stratiform precipitation. For example, shallow and deep convective precipitation, isolated and embedded convective precipitation seem to show different characteristics in the distribution of hydrometeor and DSD, respectively. However, a few studies have documented and compared the three-dimensional characteristics of cloud microphysics in the precipitation on the basis of the observational data. In the present study, three-dimensional characteristics of polarimetric radar variables for several convective and stratiform precipitation cases over the East China Sea are studied, mainly using the observational data of COBRA (CRL Okinawa Bistatic Polarimetric RAdar). Radar reflectivity factor (Zh), differential reflectivity (Zdr), correlation coefficient (rHV) and their relations are investigated to characterize the cloud microphysics in each precipitation. Classification of precipitation type based on the three-dimensional distribution of hydrometeor in each precipitation will be discussed.