THE RELATIONSHIP OF LEADER AND RETURN STROKE PROCESSES IN CLOUD-TO-GROUND LIGHTNING

The unique relationship between the leader and return stroke in cloud- to-ground flashes and the ambient cloud potential distribution is form ulated. This relationship in the form of a ratio of an electric field produced by a leader, Delta E(l), to that of a return stroke, Delta E( r), is analyzed for two electrostatic leader models, the bi-directiona l leader and the Schonland ''source charge'' models, and is then compa red with field measurements. It is found that the Delta E(l)/Delta E(r ) ratios of real flashes fall between the curves of the ratios calcula ted for the two leader models, with each model representing an extreme condition of ambient electric field distribution.