Over The Horizon

Great Balls of Lightning!

A mountainous area in Japan which is the traditional home for the mysterious lights known locally as kitsune-bi (fox-fire), was the venue recently for the Fifth International Symposium on Ball Lightning. Delegates came to Tsugawa from as far afield as Russia, Austria and New Zealand to discuss ball lightning and theories on the phenomenon's formation.

The vortex burner theory of New Zealand researcher Peter Coleman came in for special mention by Dr Stanley Singer, president of the International Committee on Ball Lightning (ICBL) as a candidate theory for explaining the phenomenon. Coleman suggests that ball lightning involves the combustion of a fuel gas within a naturally occurring atmospheric vortex. When a sudden reduction in the speed of the vortex core occurs, radial expansion results producing a bubble-like shape [Ball Lightning Dec/Jan 95/96].

At the conference, Coleman presented a paper which indicated the vortex burner theory could explain a number of anomalous atmospheric phenomena (themselves scientific puzzles, treated as distinct from ball lightning), such as bead lightning. Bead lightning is a phenomenon which is apparently even more rare than ball lightning. In a lightning storm a number of lights are seen in a long line, persisting far longer than the lightning stroke itself. The beads may be a series of ball lightnings strung together -- a chain of vortex burners created in the wake of a lightning stroke.

Hessadalen Valley, in Norway, is the site for an unusual light that frequently exhibits a peculiar motion. Scientific field studies have revealed the property and behaviour of these lights but not their nature. Hessadalen is subject to earthquake tremors and is near a fault, so the possibility of the emission of natural gas cannot be discounted. This would provide a fuel gas to feed a vortex fireball, and the vortex theory predicts that ball lightning will be seen more frequently along seismically active zones where there is an emission of natural gas.

A huge revolving fireball seen on the axis of rotation of the Newbottle tornado (30 September 1972) is a prime candidate for explanation by the theory. The reduced air speeds in the vortex breakdown would provide a conducive environment for combustion to take place.

Peter Coleman is author of Ball Lightning -- A Scientific Mystery Explained, to be published shortly by Fireshine Press. For further information contact Colemanpf@xtra.co.nz