Interaction between lightning channel and CTS

Ion current starts to flow into surrounding air from all objects on the ground when the electric field produced by the charges in thunderstorm clouds and in a stepped leader will reach some critical value, E/sub on/. Calculations of the total electric field of the lightning channel at the points close to the ground do not usually take into consideration the component originated by the space charges produced by those ionic currents from the ground objects. The efforts to evaluate the influence of the space charge on the total electric field are undertaken in this paper. It was shown that a relatively small space charge, q/sub se/, above the sharpened points, (a small fraction of the charge of the stepped leader) causes a significant reduction of the total electric field strength at the points. This is because the electric field is proportional to the size of the charge but inversely proportional to the square of the height of this charge. A simplified model of a thunderstorm cloud and average lightning properties of a thundercloud cell and stepped leader were employed to calculate the electric field at the ground level for each single step of the leader. Calculations of the space charge were based on the experimental data of the charge transfer system (CTS) performance under influence of the changing electric field. The number of points of the CTS was varied from 1 (lightning rod) to 10000 (dissipation array system-DAS). The calculation results of the interaction between the lightning channel and the space charge clearly show that starting from certain heights above the ground of the tip of a stepped leader the influence of the space charge on the total electric field is very significant and can not be neglected. It is especially important.