Abstract
This paper discusses the availability of the vertically integrated liquid (VIL) water content product from 3-cm wavelength polarimetric radar in precipitation detection and estimation. Based on a case of localized severe rainfall around Zoshigaya, Tokyo, Japan on 5 August 2008, VIL values are compared with radar derived rain intensity and surface rain-gauge data. VIL is calculated by three methods: (1) using only the horizontal reflectivity (Z), (2) using only specific differential phase (KDP), and (3) using both Z and KDP. Two integral height scales are tested: a height near the melting layer (5 km) and a height over the echo top (15 km). The composite method of Z and KDP proved to be the best approach for calculating VIL. VIL values were consistent with gauge measurements: the maximum normalized cross-correlation coefficients at all three observation sites (Edogawa Elementary School, Daiichi Junior High School, and Toshima Branch) exceed 0.9, and detection by VIL has a 5-10 min lead time than gauge measurements.
