【作者】 徐良韬；

【导师】 张义军；

【作者基本信息】 中国气象科学研究院 ， 大气物理学与大气环境， 2012， 硕士

【摘要】 本文将雷暴云的起电、放电物理过程引入中尺度的WRF (Weather Research andForecasting)模式，并对超级单体、飑线和台风过程进行了模拟研究。起电过程在Milbrandt双参数微物理方案中写入，包含霰、雹与冰晶、雪之间的非感应起电机制，以及霰、雹与云滴之间的感应起电机制。放电参数化方案考虑了闪电的整体效应。对一次超级单体的模拟结果表明，电荷结构呈现正、负、正的三极性结构，主正电荷区在-40oC到-60oC之间，主负电荷区在-10oC到-30oC之间，下部正电荷区在零度层附近，总电荷浓度最大值接近2nc/m3。这种电荷结构的垂直分布同以往在强对流天气系统中观测到的典型电荷结构一致。对飑线过程的模拟结果表明，部分单体电荷结构呈现出反的偶极性且飑线中最大电荷浓度小于超级单体。分析发现粒子间相互碰撞的起电位置主要在反转温度层以下，使得霰粒子荷正电，而冰晶粒子荷负电，导致了电荷结构极性的反转。在飑线成熟阶段，模拟得到的闪电分布与观测的地闪活动在分布型上相似。同化雷达资料后模拟的累积降水量和闪电活动都同实际观测更加接近。对台风的模拟结果表明，在台风外雨带中，模拟出的闪电活动分布同实际观测的地闪活动在位置上相接近，在台风内雨带中，地闪定位系统没有探测到地闪，但是模式模拟出了部分闪电活动，台风内雨带中可能存在云闪活动。更多还原

【Abstract】 The processes of cloud electrification and lightning parameterization are introduced intothe Weather Research and Forecasting (WRF) model, in which the supercell, squall line andtyphoon are simulated. The numerical formulation of the electrical processes includes thenoninductive graupel-ice, hail-ice, hail-snow and inductive graupel-cloud, hail-cloud chargeseparation mechanisms coupled with the Milbrandt two-moment microphysical scheme. Inthe mean time, a bulk lightning parameterization is considered in the model.On the one hand, the simulation of supercell produced a normal tripolar charge structure,consisting of a main negative charge region (-10oC to-30oC) with an upper main positivecharge region (-40oC to-60oC) and a lower positive charge region (near0oC). The maximumtotal charge density is approximately2nc/m3. The simulated vertical profile of chargestructure is in accordance with the previous classical structure observed in the severeconvective weather.On the other hand, the simulation of the squall line showed the inverted dipolar chargestructure in some cells and the maximum total charge density is smaller than that of thesupercell. The result also showed that the charge separation process take place mainly belowthe level of charge reversal, hence the graupel particles charged positively and the iceparticles charged negatively, leading to the reverse of the charge structure. Moreover, thesimulated distribution of lightning density is similar with observed cloud-to-ground (CG)lightning density in the mature stage of the squall line. While the predicted distribution of theaccumulative rainfall and lightning activity with assimilation of radar data are more similarwith the observation.The simulation of typhoon indicated that the simulative distribution of the CG lightningactivity is close to the observation in outer rain band. In the inner rain band, No CG lightningwas detected by the CG lightning location system, whereas the simulation showed somelightning activity which suggested that the intra-cloud lightning activity may exist in innerrain band.更多还原