Simulated Impacts of Two Adjacent Cloud-To-Ground Lightning Flashes on the Sprite Inception by Using a Three-Dimensional EMP Model

To evaluate the impacts of two adjacent cloud-to-ground (CG) lightning flashes on the sprite inception, a three-dimensional (3D) EMP model is built in this paper using finite-difference time-domain (FDTD) method. It is found that, compare to a single +CG flash case, the electric field amplitude generated by two adjacent +CG flashes increases after superposition, which is favorable to the initiation of sprite. Conversely, two neighboring CG flashes of opposite polarity are not conducive to the initiation of sprite. The generation of adjacent CG flashes also provides a new explanation for the causation of horizontal offset between discharge channel and sprite.