Variability of Microphysical Characteristics in Different Climate Region and Precipitation System

The drop size distribution (DSD) is a key component to understand the microphysical process of precipitation systems and to improve the accuracy of rainfall estimation. The variability of DSD is affected by not only climate regimes but also precipitation systems. In this study, the variability of DSD is examined in different climate regimes (Daegu in East Asia; DG and Oklahoma in the US; OK) and four different precipitation systems using the generalized DSD parameters (generalized number concentration; N0’, and generalized diameter; Dm’) derived from disdrometric measurement and dual-polarimetric radar observation.The generalized DSD parameters contain significant microphysical information and are calculated from 3rd and 4th moments of DSD. The DSD data collected from 2DVD during 2011-2012 years in DG and 1998-2006 year in OK are used to investigate the DSD variation according to climate regimes.

The spatial variations of generalized DSD parameters are derived from S-band dual-polarization radar for foure different precipitation systems (isolated storm, squall line, cloud cluster and Changma) based on classification of Lee and Kim (2007) using the radar reflectivity and EIR (enhanced infra-red) image of the satellite. Results shows very distinctive feature of warm rain process in East Asia and dominant ice biophysical processes in Oklahoma. Evolution of DSDs as functions of increasing rainfall intensity is quite distinctive for four different systems, manifesting different controlling growth mechanism. We will further emphasize effect in rainfall retrieval due to this distinctive microphysical feature.