Well, what do the educated people here think?

They exist, no question, but why?

What causes them?

I saw a rather sansationalist programme recently, but it suggested
that they were something to do with "positive lightning".

It suggested that these opposite-from-usual-polarity lightning strikes
were much more energeric tham normal strikes, and that the sprtes and jets
were coincident with those strikes.

Interested in opinions.

M.A.Poyser Tel.: 07967 110890
Manchester, U.K. http://www.fleetie.demon.co.uk