Numerical Simulation of the Effects of the Aerosol on Thunderstorm Cloud Charge Structure
|School||Nanjing University of Information Engineering|
|Course||Of lightning scientific and technical|
|Keywords||Aerosol Numerical Simulation Charge Quantity Multi-layer Charge Structure|
In this paper, we have joined the aerosol module into an existing thunderstorm electrification model, and completed the thunderstorm electrification process in the two-dimensional (2D)250meters’numerical simulation. Meanwhile, the correctness of the program is tested with the actual sounding data. For the purpose of examine the aerosol impact on micro-physical and the electric process, a thunderstorm electrification model is established initially. Moreover, by changing the initial concentration and spectral distribution of the aerosol in the model, we have found the changes in the charge structure of thunderstorm, that will provide a theoretical basis on actual thunderstorm charge distribution, and propose a new insight. The numerical simulation of the results obtained as follows:(1) Based on the existing thunderstorm cloud model by Mansell and Tan Yongbo’s works, we have completely joined the aerosol module into an existing thunderstorm electrification model, and contrasted with the classic model which is considered the cloud droplet number concentration by the empirical formula. After joining the aerosol module, the model still has a good ability to simulate the thunderstorm cloud at the250meters resolution.(2) By increasing the concentrations of the aerosol, the charge density and the total charges in the thunderstorm cloud is increased, but the peak time they reached is not be affected. The thunderstorm cloud turns the simple polar structure to the multi-polar structure. The increase of every layer of charge heap is not uniform, mainly concentrated in the middle of the main negative charge heap and the bottom of the positive charge heap.(3) The different scale of the initial aerosols spectral distribution have a significant impact on the distribution of the charge structure in thunderstorm clouds space. The aerosol which particle spectrum in the radius is greater than1μm has a considerable contribution to the generation of thunderstorm charge structure. With the increase of the giant particles, the more obvious negative charge heap appeared at the bottom of the thunderstorm cloud, that charge heap occurrence is closely related with polarity reversal caused by space charge heap concentration unevenly increase.