Tuesday, June 27, 2006

Rare "Rainbow" Spotted Over Idaho


It looks like a rainbow that's been set on fire, but this phenomenon is as cold as ice. Known in the weather world as a circumhorizontal arc, this rare sight was caught on film on June 3 as it hung over northern Idaho near the Washington State border.

The arc isn't a rainbow in the traditional sense—it is caused by light passing through wispy, high-altitude cirrus clouds. The sight occurs only when the sun is very high in the sky (more than 58° above the horizon). What's more, the hexagonal ice crystals that make up cirrus clouds must be shaped like thick plates with their faces parallel to the ground.

When light enters through a vertical side face of such an ice crystal and leaves from the bottom face, it refracts, or bends, in the same way that light passes through a prism. If a cirrus's crystals are aligned just right, the whole cloud lights up in a spectrum of colors.

This particular arc spanned several hundred square miles of sky and lasted for about an hour, according to the London Daily Mail.

5 comments:

JaundiceJames said...

That's awesome. Thanks for that.
The religious loonies must have thought it was some kind of gay invasion. -JJ

Parge said...

Wow! I actually witnessed this first hand that same day. I was actually quite a distance northwest of there in Vancouver. I thought it was an odd phenomenon when I saw it so I snapped a photo of it. I've posted it on my blog. Thanks for the info!

Stardust said...

jaundicejames- maybe it's a sign from gawd for his support of gays :)

parge --That must have been a fantastic sight to see that with your own eyes! When I see magnificent photos like these I always regret that I was not there to see it for myself.

Delta said...

The religious loonies must have thought it was some kind of gay invasion

"Hurry! Everyone put in their Jesus butt plug!"

And awesome pic stardust.

Stardust said...

delta - You are such a "sinner" LOL!
Maybe they make them in allah shape too for lightbulb guy featured in another post???