Numerical Modeling Studies of Thunderstorm Charging and Lightning Influence on Storm Electricity in Two and Three Dimensions

本研究的目的是雷暴的电气化物理，包括闪电放电，使用一个数值云模型。最近的实验室结果表明，温度和液态水含量都具有重要意义。此外，还将研究冰分裂在产生低正电荷中心中的意义。闪电参数化方案的改进将包括基于放电尖端附近随机自由电子存在的传播路径的随机化，在路径计算中包含尖端电场，以及云对地放电的模拟。这些改进和上面提到的将被纳入三维模型。我们将把麦克斯韦电流的计算纳入我们的分析软件，以测试Krider和Musser（1982）关于感应和非感应过程在驱动麦克斯韦电流中的作用的推断。将使用2D和3D模型对几个新案例进行建模研究，以检查各种风暴中的电气化过程。

The objective of this research is the physics of electrification of thunderstorms, including the lightning discharge, using a numerical cloud model. The formulation of riming charge transfer will be guided by recent laboratory results showing the significance of both temperature and liquid water content. Also, the significance of ice splintering in producing lower positive charge centers will also be investigated. Improvements in the lightning parameterization scheme will include a randomization of the propagation path based on the presence of random free electrons in the vicinity of the discharge tip, the inclusion of the tip electric field in the path calculation, and a simulation of the cloud-to-ground discharge. These improvements and those mentioned above will be incorporated in the three-dimensional model. We will include a calculation of the Maxwell current into our analysis software to test the inference of Krider and Musser (1982) concerning the role of inductive and noninductive processes in driving the Maxwell current. Modeling studies of several new cases will be undertaken with both 2D and 3D models to examine electrification processes in various storms.