Rainbows are formed when beams of sunlight hit a raindrop and separate into various colors. A circumhorizontal arc, on the other hand, happens when light passes through clouds at a high-altitude. The light is refracted through the cloud's ice crystals and forms a bright color spectrum.
So even though the most glaring issue with the name is the use of the word "fire" — fires have nothing to do with this — the biggest problem is that there was no rain involved in the formation of Sunday's circumhorizontal arc.
The term is a "complete misnomer, akin to identifying a conventional gasoline engine as an electric motor," says Raymond Lee, a meteorologist at the US Naval Academy. That said, given the ongoing drought in California, it's pretty refreshing to see such positive coverage of a weather event in the US. But just make sure you call this colorful phenomenon by its proper name.
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Fire rainbow at at Atlantic City International Aiport in New Jersey. (Matt Hecht / Wikimedia Commons)
Fire rainbow in Austin, Texas. (Mrsburton / Wikimedia Commons)
Fire Rainbow at Emerald Isle beach, NC (Timothy Shauger / Wikimedia Commons)
Fire rainbow taken near the Kennedy Space Center in Florida. (Bulent abali / Wikimedia Commons)
(Matthew Plew / Wikimedia Commons)
Read more http://www.theverge.com/2015/8/22/9186973/heres-why-you-shouldnt-call-this-a-fire-rainbow
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