BALL LIGHTNING SOLVED

A statement of the essential elements of my ball lightning theory is contained in the letter to the Royal Meteorological Society of the UK in publication called 'Weather' Jan 1993 vol 4, No 1, page 30.

An explanation of ball lightning ?

“Vonnegut (1991) identified the Dorset tornado of December 1989 (Brown 1990) as a kind of “prester” whose luminous activity was possibly of an electrical nature. It was said to have resembled a “twisting ball of fire” to the farmer who observed the phenomenon. An alternative explanation of this luminosity is the combustion of an atmospheric fuel such as natural gas, within the tornado. However any flame would be quickly blown out by the high air-speeds. The only conceivable way combustion could occur is when the tornado undergoes axisymmetric vortex breakdown where there is a great reduction in air velocity.

Such a phenomenon does, on occasion, take place. Particularly clear observations of vortex breakdown of the Minneapolis tornado of 18 July 1986 were reported by Pauley and Snow (1988). Once this air speed reduction occurs, then it becomes possible that the flame speed can match the air speed. In fact, this matching will define the flame boundary. In addition, the vortex core expands laterally and a bubble-like recirculation region is established. The “ball of fire” observation might then be explained on this basis.

Actually, the observation of the Dorset tornado appears to bear a close resemblance to an event reported by Campbell (1982) near Crail in Scotland in 1968. There, a whirlwind was observed in the middle of Roome beach in close association with a ball lightning object which had a 200 mm diameter and was 0.5 m off the ground. This sort of observation indicates that ball lightning might well be explained as a vortex acting as a burner of combustible fuel such as natural gas or other.”

Peter F. Coleman, Lincoln University, New Zealand.

References.

Brown, R., (1990), Tornado in North Dorset: 21 December 1989, Weather, 45, p.240.

Campbell, S., (1982) Ball Lightning at Crail-1968, Weather, 37, pp.75-78.

Pauley, R.T. and Snow, J.T. (1988), On the kinematics and dynamics of the 18 July 1986 Minneapolis tornado, Mon. Wea. Rev., 116, pp. 2731-2736.

Vonnegut, B., (1991) Presters, Weather, 46, pp. 360-361.