A Shielding Theory in Consideration of Upward Leader Initiation

Abstract

A shielding theory which considers upward leaders from high structures is proposed to predict the characteristics of lightning strokes to high towers on the coast of the Sea of Japan in winter season. In this theory, it is assumed that when the electric field at the top of a tower exceeds a critical value by the charge in thunderclouds, an upward leader begins to develop and lightning strikes the tower. Calculated shielding characteristics of high towers are compared with field observations.