Physics Photo of the Week
November
21, 2008
Flying Figures - Photos by Doug Sudduth, Bakersville, NC
These are lenticular clouds. Doug Sudduth has a major hobby of
collecting photos of fascinating lenticular clouds from his home north
of Mt. Mitchell in North Carolina. Doug photographed this amazing
"flying elephant" in mid-February, 2008. The camera is looking
south east at about 3:30 pm.
Mt. Mitchell in the Black Mountain range is to the right and about 25
km distant - out of view of the photo. Even though Mt. Mitchell
is fairly distant from these clouds, it is believed to contribute
highly to the formation of these clouds that appeared about 25 km
northwest of the range. Lenticular clouds form only on fairly
rare days when the air is very stable against thremal convection.
Normally, when clouds form, the heat released by the condensation of
water vapor heats up the air in the cloud and gives it buoyancy in the
surrounding air. As a result, most forming clouds rise to give
the pillowy cumulus clouds. However, if the upper air is warmer
and less dense
than the lower-level air, the condensing cloud doesn't have enough
buoyancy
to rise, and the cloud material moves horizontally making eerie
lens-like shapes - hence the name "lenticular". Air deflected
over
mountain ranges often triggers the formation of lenticular clouds as in
the drawing at right.
More ghost-like clouds from the same day are shown below. Doug
has named these clouds in memory of his late friend Bruce Ledford who
was also an avid lenticular cloud photographer.
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Due to Thanksgiving vacation at Warren Wilson College, there will
be no
Physics Photo of the week on November 28. The next Physics Photo
of the Week will appear on December 5, 2008.
Physics
Photo of the
Week is
published weekly during the academic year on Fridays by the Warren
Wilson College Physics
Department. These photos feature an interesting phenomena in
the world around us. Students, faculty, and others are invited to
submit digital (or film) photographs for publication and
explanation. Atmospheric phenomena are especially welcome.
Please send any photos to dcollins@warren-wilson.edu.
All photos and discussions are copyright by Donald
Collins or by the person credited for the photo and/or
discussion. These photos and discussions may be used for private
individual use or educational use. Any commercial use without
written permission of the photoprovider is forbidden.
Click
here to see the Physics Photo
of
the Week Archive.
Observers are invited to submit
digital photos to:
