3d Simulation of Positive Corona Effect On the Upward Leader Initiation of Tall Building

The initiation of the stable upward leader (UL) is an important criterion to judge whether a building can be struck by lightning. Corona discharge in thunderstorm will affect the initiation of UL. However, there are few studies on the degree of its specific impact. Therefore, based on the established three-dimensional (3D) corona discharge model and the dynamic critical length criterion model (This article uses DCLCM to abbreviate) as reported by Guo et al. (2020), an UL initiation model with corona discharge has been established in this paper. It is found that the model after considering the corona discharge is closer to the observations. The model has been used to simulate buildings with different heights and different peak current of lighting strike (IP). And the downward negative cloud-to-ground lightning with positive corona discharge effects on the positive UL initiates from the building tip have been discussed. The results show that: 1) For the certain IP, the effect of corona discharge has greater effects on the taller building than the short one. 2) For the same height of building, with the decrease of the IP, the greater the effect of corona discharge. For example, when the IP is 30 kA, the effect of corona discharge on the stable UL initiated from a 200 m building can be up to 30%.