Relation between the near-Earth electric field at high latitudes and intense cloud-to-ground lightning strokes initiating VLF emission bursts

Since 1998, the gradient of the near-Earth atmospheric electric field potential ( vertical bar Ez vertical bar) has been continuously registered at Vostok Antarctic station within the scope of the joint Russian-Australian project. The data of the continuous 10-day period of fine weather in April 1998 have been selected for the following analysis. The field vertical bar Ez vertical bar behavior at Vostok station was compared with a number of lightning strokes obtained from data of the ground-based network of electromagnetic measurements. It has been found out that the average hourly values of vertical bar Ez vertical bar evidently negatively correlate with the number of intense lightning strokes. The causes of these relations are discussed. The obtained results are interpreted based on a theory of global electric circuit.