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Old December 5th 05, 10:18 AM posted to rec.aviation.soaring
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Default New Mexico Fire-Devils

Eric Greenwell a écrit :
W.J. (Bill) Dean (U.K.). wrote:
If thermals rotate, why don't the clouds rotate?


Apparently, most thermals lose what rotation they have by the time the
cloud forms, or perhaps forming a cloud causes the end of the rotation.
I have seen (albeit rarely) dust devils that went to cloud base at 6000'
to 8000' agl, but did not notice any rotation in the cloud itself. The
diameter of the dust devil was much less than that cloud diameter, so I
would not expect the entire cloud to rotate.


If the rotation is stationary, you cannot see the rotation of the cloud,
just as you cannot see lenticular clouds move... But if there are dust
devils, clouds do rotate !


--
Denis

R. Parce que ça rompt le cours normal de la conversation !!!
Q. Pourquoi ne faut-il pas répondre au-dessus de la question ?