(TMU) — The term “Fire Rainbow” is a perfect example of a misnomer. But while the name is totally inaccurate and the phenomena has absolutely nothing to do with fire or rainbows, it does seem a much more appropriate term for an optical phenomena actually called circumhorizontal arcs.
What makes fire rainbows particularly special is the fact that they need very specific conditions to occur.
First, the sun must be higher than 58 degrees in the sky. Second, they require cirrus clouds—those wispy, thin clouds that are formed at higher altitudes where the air temperature is low enough to form the clouds from hexagonal (six sided) ice crystals. And third, these conditions need to be perfectly aligned for the ice crystals to act as a prism to create refractions and reflections from the sunlight, resulting in a horizontal “rainbow” display of color.
View this post on Instagram
Witnessed a pretty cool phenomenon out on lake sammamish today. A horizontal rainbow! 🌈 To me it was a little reminder to hold onto hope and love instead of fear and panic in these unknown times. Stay safe out there, friends💞 #rainbowsofhope #flattenthecurve . . The second photo is available for purchase on my website! Link in bio 🙂
In spite of the exacting requirements, this iridescent halo effect is not as rare as one might think. Their frequency depends on the required conditions being in the right location in a particular latitude in the northern hemisphere during summer, notably in the months of June and July in the USA. They often appear on the horizon and beautiful examples have been captured above the clouds through aircraft windows.
On their website, International Cloud Atlas explains:
The circumhorizontal arc occurs only when the elevation of the light source is more than 58°. When the Sun reaches an elevation of about 68°, the circumhorizontal arc reaches its maximum intensity. In countries north or south of latitude 55°, the circumhorizontal arc cannot be seen because the Sun is always lower than 58° there. So, this is one of the few haloes that is not visible everywhere on Earth.
In March of this year, photographer Cessna Kutz captured a magnificent fire rainbow over Lake Sammamish, King County, Washington State.
Cessna shared her stunning photos on her Instagram and wrote of the experience, saying:
“Witnessed a pretty cool phenomenon out on lake Sammamish today. A horizontal rainbow! To me, it was a little reminder to hold onto hope and love instead of fear and panic in these unknown times. Stay safe out there, friends.”
The only person surprised that the photos went viral and made the news was Cessna herself, who said:
“I honestly had no idea these photos would make the news. I was just wanting to share a beautiful moment I got to witness. I’m super passionate about photography so I’m grateful that God has used my photos to touch people, not only throughout the nation but throughout the world. It’s boosted my photography business as well as make an impact on people so it feels pretty amazing.”
Thanks to social media, posts like Cessna’s bring a ray of light into the lives of millions of people during this unprecedented time of lock downs and shelter in place orders.
This too shall pass, so be patient and please stay in place and stay safe!