抄録
The authors observed the thunderclouds in winter season using a C band dual polarization radar in 1989, 1990, 1992 and 1993. We have investigated the distribution and the movement of the precipitation particles, especially graupel and ice crystals which play an important role in the riming electrification theory that is perceived as an potent electric charge generation mechanism in the thunderclouds. As a result, we have reported that there is a close relationship between the mixing of graupel and ice crystals and the lightning discharge.
In this paper, we denote the validity of the discriminating method of the precipitation particles, namely graupel and ice crystals by the radar reflectivity (ZH) and the differential radar reflectivity (ZDR) of the dual polarization radar in comparison with the sonde data, observed simultaneously.
Also, we have proposed two types of predictable parameters for the lightning discharge occurrence based on the discrimination method of the precipitation particles mentioned above, and we discuss the applicability of these predictable parameters.
