Continuing current intensity in positive ground flashes

The highest directly measured lightning currents and the largest charge transfers to ground are thought to be associated with positive lightning. Brook at al. [1] for one positive lightning in a winter storm in Japan, inferred a charge transfer in excess of 300 coulomb (C) during de first 4ms. But charge transfers to beyond 3000C were reported from direct current measurements, by Miyake et al.[1] for positive winter lightning in Japan. Positive strokes may have high peak currents followed by long continuing current (CC), and thus combine these two threatening features for lightning protection. Although positive flashes are usually less frequent than negative lightning, the special characteristics of their CC make the understanding of positive lightning an important issue. Positive lightning were recorded in southeastern Brazil during the summers of 2009-2011. This study presents some CC intensity estimates obtained from an electric field capacitive antenna. Most CC intensities were much higher than the usual intensity values of CC in negative flashes.