Solar Halo

Nic Name • May 17, 2002 7:12 pm
Image

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)
verbatim • May 17, 2002 9:05 pm
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.
Count Zero • May 17, 2002 10:52 pm
I saw something like that around the moon once. It was much bigger too.

Quite strange.
Pie • May 18, 2002 1:27 pm
"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