Further Discussion on Deriving Drop-Size Distribution and Vertical Air Velocities Directly from VHF Doppler Radar Spectra

Abstract

Raindrop size distribution and vertical air velocity are directly derived from VHF Doppler radar spectra in precipitation environments. As was first proposed by Wakasugi et al., we use a least-squares fitting parametric estimation for VHF Doppler spectra to determine the distribution and air motions. After discussing further the VHF Doppler spectrum method, especially the effects of spectral broadening mechanisms, the method is applied to Doppler spectra obtained during the seasonal rain front (Bai-u front) observation in Japan. Variations of vertical air velocity and distribution parameters are discussed, based on this longer period dataset.