Someone showed me a photo of a “Fire Rainbow”, a rainbow image on cirrus clouds.
I think this is a doctored photo. According to the article, Fire Rainbows are very rare and happen only when the sun is at “exactly 58 degrees” it then went on to say that this Fire Rainbow lasted almost an hour. I don’t think that adds up, after all wouldn’t the sun change position by 15° during that hour?
Recap of the questions: Do FRs exsist and if they do could they last an hour?
Here is a clickable version of the link, for the truly lazy.
I think it’s real, if for no other reason than the image is copyright Associated Press, as you can see in the bottom right corner. The AP isn’t known for faking photos, insofar as I’m aware.
I’m sure it’s real, however the sky is too deep a blue. The publisher probably jacked up the color saturation. That’s pretty common with pictures of iridescent clouds.
You can find many more photos of iridesence at this Atmospheric Optics page.
I’ve seen 'em fairly often, at least 10-12 times over the years. They’re rare but not all that rare. Certainly not as rare as the black ring around the sun phenomenon.
If you are lying on your back in the cool, sweet grass on a hot July day, lazing in the sunshine, and watching the clouds go by high above… Oh, sorry, lost in a summertime reverie, there. Anyway, if you look carefully at clouds on a sunny day, you can see bits of ‘rainbow’ at the edges. It’s the same principal, I believe, and a highly enjoyable way to spend a half hour.
I have never heard the term “fire rainbow” before. Is this phenomenon related to that of nacreous clouds?
I remember seeing the very display shown in the photo I just linked to. It was in February 1996 and I had just emerged from the university bar in Sheffield. I honestly thought I was seeing things, it was a truly amazing sight, which this photo does not do justice to.
Actually, my guess would be that the photographer used a polarizing filter; it blocks out a larger fraction of the light from the sky than from the clouds, and you’d get much the same effect without any need for post-processing shenanigans.
I’m glad this thread came along. I spotted an iridescent cloud hanging in the Austin sky over my office this past Tuesday. Having never seen anything like it I pointed it out to a coworker, but didn’t have a camera at hand.
If you follow the link **Squink **provided, the one I saw looked a lot like the last photo in the third row.
I’ve seen this phenomenon on the Palouse (the area along the Washington/Idaho border). The sky is not “too blue”. The sky really looks like that sometimes in that area.
I see this kind of thing pretty often, just not as big and vibrant. Little patches close to sunset are not uncommon around here. I think my old man used to call it a “false sun,” though I have no idea why.
I don’t know if this is relevant or not. When I fly, in a private plane, close the the clouds, I can see the shadow of my plane on the cloud below. If the conditions are right, there is a rainbow - in a complete circle - surrounding the shadow of my plane.
I’ve always wondered what caused this. I guess it’s just the sun reflecting off the water crystals in the cloud.
Also similar, and very cool, are sun dogs. I saw some very bright vivid ones in Seattle early this winter. They lasted about fifteen minutes, and had a beautiful spectral rainbowish spread.