数值模拟研究北京地区冰雹云宏微观特征和闪电特征.doc

文档介绍：
数值模拟研究北京地区冰雹云宏微观特征
和闪电特征#
马明,张闯创,祝宝友*
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(中国科学技术大学地球和空间科学学院,合肥 230026)
摘要:采用雷暴云起电、放电数值模式模拟了北京地区 12 次雹暴天气过程,研究北京地区
冰雹云的微物理过程和电过程。在冰雹云的快速发展阶段,模拟的闪电频次呈现出“跃增”
现象,且闪电频次的峰值时刻提前于地面降雹时刻。闪电频次“跃增”是动力、微物理过程和
起电过程综合作用的结果,“跃增”前冰晶与霰的比水量都发生了“跃增”现象,它们的碰撞速
度同时增大,此时非感应起电机制发挥作用,起电过程迅速加强,云内电荷浓度快速增强,
云内电场也迅速增长并且维持较强电场,电场强度高过放电阈值产生放电现象,因此造成闪
电频次的“跃增”。
关键词:大气电学数值模拟冰雹云微物理过程闪电
中图分类号:P41
The Numerical Simulation of Macro and Micro-physical
Characteristics and Lightning Characteristics in Hailstorm
of Beijing
Ma Ming, Zhang Chuangchuang, Zhu Baoyou
(School of Earth and Space Sciences,University of Science and Technology of China, Heifei
230026)
Abstract: In this paper, in order to study the processes of microphysics and electrification in
hailstorm, we used a Thunderstorm Electrification and Lightning Model to simulate 12 hailstorms
in Beijing. There is a distinct intensive increase in lightning frequency in the quickly developing
period of hail cloud. Cases indicate that the peak lightning frequency occurs earlier than the time
of hailstone falling. The analysis shows that the reason why there is a distinct intensive increase in
lightning frequency in the quickly developing period of hail cloud is bined result of
dynamical and microphysical processes. Before the distinct intensive increase happening, the
water contents of ice and graupel particle