雷暴云下空间电荷层形成的数值研究

A Numerical Study of Space Charge Formation Beneath Thunderstorm

利用一个引入了地面尖端电晕放电物理过程的二线轴对称积云起电模式，讨论了雷暴云下空间电荷层的空间分布和随时间的演化规律。在模式计算上采用了“时步分离法”，即在小时步上计算电导及各种反极性离子的复合作用，在大时步上计算平流、对流和湍流扩散项，对于不同的时间步长垂直方向采用不同的格距。通过模拟分析，得到了一些较为合理的结果。最后简单地讨论了本工作在以后需改进的地方。

With a two-dimensional axissymmetric model and a ground corona discharge model, we have numerically calculated the temporal and spatial distribution of space charge density and analyzed the formation of space charge layer, especially concerning transportation mechanism for all kinds of ions, under the thunderclouds. The results show that ground point discharge is always controlled by electric structure in the low part of the thunderstorm. On the other hand, ground point discharge, in, turn, emprass the development of electric structure inside the thundercloud.