Electrical Phenomena in Thunderstorms

by Mrs Laetitia Gibaud (Keraunos - Observatoire Français des Tornades et Orages Violents)

Tuesday 18 Feb 2014, 17:00 → 18:00 Europe/Berlin

Auditorium (MPI fuer Physik)

While being the most spectacular event of a thunderstorm, lightning is the detectable manifestation of the electrical structure of the thundercloud "Cumulonimbus". The triggering of lightning flashes indeed implies the separation of electric charges in the cloud. The first part of this presentation will be dedicated to the electric charges cycle: from the electrification of the cloud to the redistribution of charges. We will see that there are different types of lightnings. I'll illustrate these mechanisms with photos from my storm chasing activity. Less familiar, another electric discharge phenomenon is observed above storm systems. A review of these short optical emissions, called transient luminous events, is presented in the second part. We will see that all these electrical discharges are an important factor in the electrodynamic coupling between troposphere and the mesosphere/lower ionosphere. Studying these exchanges give a broad understanding of what is known as the global circuit of atmospheric electricity.