Quilotoa

Can anyone tell me how this rainbow cloud is formed?

https://lemmy.ca/post/55001912

Nov 11 at 9:40pmWeb
Show threadzifkNov 11
Cloud iridescence! . Typical with thin high atmosphere clouds. When very small ice crystals or water droplets form the cloud they can diffract the light from the sun, causing an interference pattern to form. Not entirely dissimilar from an oil slick.
Cloud iridescence - Wikipedia

Show threadQuilotoaNov 11
Thanks a bunch. Are they more common in hot countries? Never seen them in Canada.
Show threadStinkyFingerItchyBumNov 11
Am Canadian. Have seen them. It’s more about altitude than lattitude.
Show threadEightLeggedFreakNov 12
Last night’s sky was especially amazing.
Show threadStinkyFingerItchyBumNov 12
Aurora?
Show threadapfelwoiSchoppenNov 12
I see them in the Midwest quite regularly. If you’re outside enough, you see them.
Show threadJul (they/she)Nov 12
What part of Canada? If west coast, probably the clouds are just typically too low and thick.
Show threadQuilotoaNov 15
Northern Ontario
Show threadAlvaro5d ago
I’m in a hot country and I have only seen it twice in my life with about 20 years between the two times.
Show threadch00fNov 11
Super interesting that this is an entirely different mechanism from a rainbow.
Show threadKrudlerNov 12

The way they are describing it isn’t entirely accurate.

It’s not an interference pattern, it’s basic refraction. And since each wavelength of incoming “white” light is refracted slightly different, you get the rainbow display

Show threadch00fNov 12

You are correct! I think the use of the word “diffraction” is a bit confusing because “diffraction patterns” are an interference effect.

So is this any different than a rainbow? The path of light must be at least different since rainbows only occur in the opposite direction of the Sun.

Show threadKrudlerNov 12
No it’s the same effect. Suspended water particulate refracting sunlight.
Show threadapfelwoiSchoppenNov 11
Similar to a sun dog.
Show threadOisteinkNov 11
Sun dogs are refraction, and these clouds are diffraction
Show threadshalafiNov 11
Oh! I thought OP’s pic was what a sun dog looks like.
Show threadapfelwoiSchoppenNov 12
I think it is, just with particular ice at a particular radius around the sun above.
Show threadameancowNov 12
If you’re really lucky and conditions are perfect, you might see a lot of updog too.
Show threadowseiNov 12

*sigh*

what’s updog?

Show threadameancowNov 12

Crap, I didn’t think it would actually work or we would get this far… I’m freezing up…

LINE

Show threadHadriscusNov 11
Niiiiice