> Another thought, or data point:
>
> People think of lightning striking under the storm, but I've seen
> lightning
> bolts come out of a cloud horizontally. One was a straight line 7 or
8
> miles long that then curved down and struck the ground nearly 10 miles
> from
> the storm.
>
> I remember it well as the pilot who normally stayed on the ground in
that
> kind of weather had just asked me how close we dared get to that
storm. It
> was as if nature heard and answered for me. <:-))
>
> Based on such a large distance it's difficult to imagine the charge
> differential that far away exceeding the differential between the
cloud
> and
> the ground under it. Particularly with all the water falling out of
the
> cloud.
>
> Of course there is far more involved than just the charge differential
> where
> lightning is involved. I do have to work though to imagine the feeders
and
> ionization following a path like that.
>
the way those happen is like this... normally charges separate in the
cloud so the negative charge is at the bottom and the positive at the
top. The negative charge at the bottom of the cloud attracts positive
charge on the ground, or you can look at it that it pushes the negative
charge away... often miles away. This is why you can get corona and
precip noise miles from a storm. Since the ground under the storm is
positive there is no incentive for the positive charge at the top of the
cloud to go there, but it does have a clear shot at the ring of negative
charge that has been pushed out from under the cloud. This makes it
natural that long and very high energy strokes to originate from the top
area of a thundercloud and strike a long distance from the cloud itself.
10 miles is not unusual. And since the top of the cloud doesn't
originate as many strokes as the bottom it usually has more coulombs
saved up so those strokes have lots of energy and long tails, thus doing
more damage than most other strokes.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://www.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
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See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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