Analysis on Radar Echo Characteristics of a Hail Cloud Development and the Physical Test of Its Hail Suppression Effect
Using the data from Zhaotong CC radar and Weining sounding station,we analyze the variation characteristics of radar basic reflectivity factor and radial velocity of the developing hail clouds in Weining,Guizhou Province on July 23,2017.At the same time,we investigate its vertical structure evo-lution of the hail clouds by interpolating to obtain profiles.Then,hail suppression effects are demonstra-ted after the time series analysis of four characteristic physical quantities of radar detection,that is,the radar echo top height,the 45 dBZ strong echo height,composite reflectivity and vertically integrated liq-uid water content(VIL).The results show that:(1)The merging of convective cells before the hail shooting increased the radar echo intensity and the VIL to more than 60 dBZ and 50 kg·m-2,respectively.The radar echo features of hail clouds such as parabolic echo and V-shaped inflow gap were also cap-tured.(2)The radial convergence of the middle and low-level airflows and the strong suction effect gener-ated by the strong divergence of the upper air produced updrafts,enabling the stable existence and devel-opment of hail clouds.(3)After the hail suppression operation,the hail cloud started to split from top to bottom until it completely split into two isolated weak monoliths.The echo top height descended signifi-cantly,and the composite reflectivity decreased by nearly 30 dBZ from the peak.(4)Within the life time of the operational unit and the comparison unit,the decrease rate of each of the four radar detecting pa-rameters of the operational unit was faster than that of the comparison unit,indicating that the hail sup-pression operation effectively suppressed the development of the hail clouds.The double-ratio analysis de-notes that the double-ratio values of the four characteristic physical quantities of radar detection were all less than 1 after 24 min,which further proves that the hail suppression achieved a positive effect and ex-pedited the dissipation of hail cloud.
radar echohail cloud characteristicshail suppression effectphysical test
NETL
NSTL
万方数据
