温湿层结对雷暴云起电过程及闪电活动的影响

为了探究环境温湿配置对雷暴云微物理、电过程及闪电的影响,本文利用法国三维非静力中尺度数值模式Meso-NH,通过改变该模式初始各层的环境温度和相对湿度,对南京地区雷暴云云微物理过程及闪电活动的发生情况进行了模拟。研究发现:大气低层、中低层环境温度和湿度的改变对雷暴云中对流强度,电场强度及分布,4种水成物粒子(雨、冰晶、雪、霰)的分布及其所带电荷量和总闪电数造成了较大影响;在低层和中低层增湿对雷暴云及闪电发生的增强效果要好于增温;在中层和中高层,降温对雷暴云及闪电发生的增强效果要好于降湿。结果表明,对低层、中低层大气环境温湿层结的影响能显著地改变雷暴云的云微物理过程,影响起电和放电,并剧烈地改变闪电活动的强度。

Temperature and humidity stratification effects on electrification process and lightning activity of thunderstorms

A mesoscale three-dimensional non-hydrostatic atmospheric model of French, Meso-NH was used by changing the initial atmospheric temperature and relative humidity of each layer, to simulate the thunderstorm and lightning flash in Nanjing, and the effect of environment temperature and humidity on thunderstorm and lightning flash analyzed. It is found that the change of temperature and humidity on lower atmosphere and middle-low level has great impact on convection intensity, the electric field intensity and distribution, the distribution and electric charge of four kinds of hydrometeors (rain, ice, snow and graupel), and the total number of lightning flash. In the lower and middle-low layers, the humidification enhancement of thunderstorm cloud and lightning is better than warming. In the middle and middle-high layers, cooling on the strengthening of the thunderstorm cloud and lightning is better than humidity elimination. The results show that the change of the lower and middle-low level atmospheric temperature and humidity condition can effectively change the microphysical process of the thunderstorm cloud, and affects the intensity of lightning activity.