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Old February 5th 05, 10:00 PM posted to uk.sci.weather
Waghorn Waghorn is offline
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First recorded activity by Weather-Banter: Dec 2003
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Default Cloud feature ober Holland


"Bernard Burton" wrote in message
...
These two images show the features quite well. They look like Von Karman
vortices, but I have also seen ones similar to these develop over the open
ocean. In that case, if they were downwind of any land it was more than
500
km away.

Processing Bernard's images reveals at least 3 vortices.I can't buy the von
Karman vortex idea as one wld expect to see evidence of pairs of
vortices.IMO the better the better analogy is with Kelvin Helmholtz
instability along a shear line -in this case a steep potential vorticity
gradient.
See eg-
A. van Delden and R. Neggers, 2003: A case study of tropopause
cyclogenesis. Meteorological Applications, 10, 197-209.
http://www.phys.uu.nl/~nvdelden/Trop.Cyclogenesis.pdf
but note the synoptic situation and resulting scale of vortex is
different.In principle the physics is similar,
regards,
David