Lightning characteristics of extreme weather events

Abstract

Lightning characteristics of extreme weather events are reviewed by first introducing the variety of thunderstorm types and large scale weather systems with embedded thunderstorms which may cause extreme events. In a description of charge separation processes, we identify the non-inductive charging mechanism as the most relevant one and outline the resulting basic charge layer distribution, the normal (or inverted) polarity dipoles and tripoles. Several case studies serve to illustrate and exemplify the concepts of the introductory part and relate the lightning evolution characteristics to hail storms, tornadoes, mesoscale convective systems, derechos or tropical and extratropical cyclones. There is compelling evidence that severe weather from thundering convection is often correlated to anomalous lightning activity, for instance signified by unusual values of lightning frequency or polarity. We also identify areas in which further research is needed, like the causes of the land-ocean contrast in lightning activity or the interrelation between recently discovered cold-ring cloud top structures and the storms' total lightning evolution (cloud-to-ground and intracloud flashes). Due to recently improved total lightning discrimination capabilities of lightning detection networks, we are confident that significant progress can be achieved in clarifying these open issues in the near future. © Springer Science+Business Media B.V. 2009.