Investigation of liquid cloud microphysical properties of deep convective systems: 1. Parameterization raindrop size distribution and its application for stratiform rain estimation

The Gamma shape and slope parameters are then compared with those derived from surface disdrometer measurements. The similar - relationships but different and value ranges from two independent platforms at different elevations may represent the real nature of DSD shape information in clouds and at the surface. To apply the exponentially fitted DSD parameters to precipitation estimation using Next Generation Weather Radar (NEXRAD) radar reflectivity factor Z(e), the terms N-0E and (E) have been parameterized as a function of Z(e) using an empirical N-0E-(E) relationship.

The averaged SR rain rate retrieved from this study is almost identical to the surface measurements, while the NEXRAD Q2 precipitation is twice as large. The comparisons indicate that the new DSD parameterization scheme is robust, while the Q2 SR precipitation estimation based on Marshall-Palmer Z-R relationship, where a constant DSD intercept parameter (N-0E) was assumed, needs to be improved for heavy precipitation cases.