Numerical Simulation of the Convective Intensity Influence on the Microphysical Development and Electric Charge Structure of Thunderstorm Clouds

In order to investigate the effect of different convective intensity on the microphysical development and electrification process of thunderstorm cloud, sensitivity experiments based on the existing two-dimensional convective cloud and discharge mode have been carried out with various disturbance temperatures. The results show that convective intensity has influences on the microphysical development characteristics, electrification rate and charge structure of the thunderstorm cloud. (1) When the convective intensity is small, the maximum value of ice crystals is located in high temperature region (above -13.8℃); when the convective intensity is large, ascending motion obviously enhances, and more water vapor is brought to upper levels. Meanwhile, the aerosol activation process significantly intensifies, the number of cloud droplets obviously increases and ice crystal particles are produced earlier and the maximum value of ice crystals is located at low temperature region (below the -13.8℃), and the development process is more intense. At the same time, the stronger the convective intensity is, the more the rainfall would be. Besides, the number of graupel particles also increases during the convection development period. (2) The non-inductive charging rate is mainly related to the collision and separation process of ice crystals and graupels. When the convective intensity is large, the non-inductive charging rate is also large, and the polarity reversal duration is obvious. This is also the case for inductive charging rate. (3) When the convective intensity is large, more complicated charge structure appears. The charge structure is tripolar during the earlier stage of the lifespan of the thunderstorm, but a smaller negative charge region is embedded during the later stage of the lifespan of the thunderstorm. When the convective intensity is small, the tripolar charge structure presents during the early stage of the thunderstorm, and the dipolar charge structure appears in the dissipating period of the thunderstorm.