FDTD simulation of field-reduction effect at ground due to corona at lightning-triggering wire

The effect of an upward-extending wire used for artificial lightning initiation from natural thunderclouds and the corona space charge emanated from this wire on the close electric field (prior to lightning initiation) on the ground surface has been examined using the FDTD method. When the wire-top altitude is 200 m, the reduction of upward-directed electric field E_z at a horizontal distance of d= 60 m is 15, 23, 28, and 38% relative to the background value at ground surface of 10 kV/m for corona radii, r = 0.27, 2, 4, and 10 m, respectively. These calculated results agree reasonably well with measurements.