Solar Halo
 

http://www.canoe.ca/May17/photo10.jpg

People in Miami were treated to a rare sight
called a solar halo in the early afternoon of
Friday, May 17, 2002. It's a localized weather
phenomon caused by a thick layer of ice crystals
in the atmosphere refracting light from the sun.
The solar halo is a precusor to a weather front.
(AP Photo/J.Pat Carter)

Ooooooooooooooooooooooooooooooooooooooooooooooo!

It almost looks like a cheap camera trick.

But doesnt it have to be cold to have ice crystals? Miami isnt the first place I think of when I think chilly.

I saw something like that around the moon once. It was much bigger too.

Quite strange.

"But doesnt it have to be cold to have ice crystals? Miami isnt the first place I think of when I think chilly."


Yes, but the ice crystals form miles above ground level. The air up there is always cold... According to one web site I looked at, the temperature at 30,000 feet up is around -50 C. (That's about cruising altitude for big jets.)

For more information on temperature variation as a function of altitude, check out http://lidar.ssec.wisc.edu/papers/pp_thes/node22.htm

Fun and games with physics!

- Pie