Calculation of Electromagnetic Fields in the Vicinity of the Lightning Channel

The electric and magnetic fields in the vicinity of the lightning channel were measured in 2004 at the International Center for Lightning Research and Testing. In this paper, a numerical lightning channel model is presented based on the physical mechanism of lightning development. The calculation of electric and magnetic fields is divided into three stages. Before the lightning leader arrives to ground, the field is induced by the charges in the thundercloud and lightning leader. During the return stroke, the field is induced by the return stroke current and the remainder charges in lightning channel and thundercloud. After the return stroke, the field is induced by the remainder thundercloud charges. The electric and magnetic fields are calculated by means of the image method and calculated fields are compared with those measured.