利用积云动力-起电二维轴对称模式,模拟分析了雷暴不同发展阶段在云中上升气流速度最大区播撒金属丝对雷暴云电结构的总体影响。通过与未播撒模拟结果相比较,发现各种降水粒子的荷电率及电场强度都有所减小,这种减小在雷暴发展的成熟阶段尤为明显,雷暴云内的扩散、电导和感应起电机制作用减弱。通过不同播撒位置和播撒率的敏感性试验得到,在云中强上升气流区播撒对垂直电场的抑制效果比在云底和云顶更好,不同的播撒率引起的电场强度减小幅度不同,播撒率存在一阈值,由此提出了播撒金属丝抑制雷暴内电过程发展的最佳方案。

A two-dimensional,axisymmetric,time-dependent,dynamic-eletrification numerical cloud model has been applied to simulate chaff seeding effects on charge structure inside the thunderstorm.Transports of the chaff fibers in the wind field are calculated and ion production by chaff in the electric field is also parameterized.The results show the chaff ions reduce not only the charge on all kinds of hydrometers by conduction and diffusion but the inductive charging efficinecy.Finally,under this ideal condition,the best way to supress electric field is advanced.