HR: 08:15h
AN: AE41A-02    [Abstracts]
TI: Transient Synchronicity and Coupling of Lightning Flashes
AU: * Yair, Y
EM: yoavya@openu.ac.il
AF: The Open University of Israel, 108 Ravutski Street, Ra'anana, 43107, Israel
AU: Aviv, R
EM: aviv@openu.ac.il
AF: Tel-Hai Academic College, Tel-Hai, Upper Galilee, 12210, Israel
AU: Ravid, G
EM: gilad@ravid.org
AF: Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva, 84105, Israel
AB: We analyzed sequences of lightning flashes in Mediterranean winter thunderstorm, based on data obtained during the 2004/5 and 2005/6 seasons from ground-based lightning location systems. Patterns of clustering and synchronicity of flashes in individual thunderstorm cells, separated by tens to hundreds of kilometers, were identified. This is similar to early findings of lightning synchronicity based on space shuttle images [Yair et al., 2006], hinting at a possible mutual electromagnetic coupling of remote thunderstorms. We developed a theoretical model that is based on the "leaky fire and integrate" approach, commonly used in models of neural activity, in order to simulate the flashing behavior of a coupled network of thunderstorm cells. In this type of network, the intensity of the electric field Ei within thunderstorm (i) grows with time until it reaches the critical breakdown value, generates a lightning flash while its electric field drops to zero, simultaneously adding a delta-E to the intensity of the internal electric field in all thunderclouds (Ej,k,l…) that are linked to it. The value of delta-E is inversely proportional to the distance between the "firing" cloud i and its neighbors j,k,l... We assumed that all thunderstorms are identical and occupy a grid with random spacing and organization. Several topologies of the thunderstorm network were tested with varying degrees of coupling, assuming a fixed probability of links between active cells. The results suggest that when the coupling in the network is higher than a certain critical value, all thunderstorm cells will eventually flash in a synchronized manner. The physical mechanisms that are possibly interacting in such a network of coupled thunderclouds will be discussed.
DE: 3304 Atmospheric electricity
DE: 3324 Lightning
SC: Atmospheric and Space Electricity [AE]
MN: 2007 Fall Meeting