Sundogs are formed when light passes through hexagonal plate crystals of ice, suspended in cirrus or cirrostratus clouds located at altitudes of around 20,000 feet (6,000 meters) and higher, up to ...

An unusual atmospheric phenomenon known as a circumhorizontal arc, or "fire rainbow," was spotted in southern Ohio, caused by sunlight refracting through ice crystals in cirrus or cirrostratus clouds.

The clouds must be very thin and made of ice crystals or water droplets of uniform size. So cloud iridescence usually happens in lenticular or alto-cumulus, cirrus and cirrocumulus clouds.

This occurs when “water droplets or ice crystals in the cloud diffract the light around the outside of the droplet, as opposed to bending the light through it,” according to Weather Channel ...

The ice crystals that make up these clouds provide a surface upon which chlorine in the stratosphere can be converted to highly reactive compounds like chlorine monoxide.

An unusual atmospheric phenomenon known as a circumhorizontal arc, or "fire rainbow," was spotted in southern Ohio, caused by sunlight refracting through ice crystals in cirrus or cirrostratus clouds.

They occur when the sun's rays interact with ice crystals or water droplets in the high-altitude clouds. That causes the light to diffract and scatter into a spectrum of the colors of the rainbow.

Rare nacreous clouds, known as rainbow clouds, form in the skies over Tynemouth Priory in the northeast of England on Dec. 21, 2023. Owen Humphreys/PA Images via Getty Images ...

Nash clarified that he is not an expert on the phenomenon but provided as much information as he could, explaining that a circumhorizontal arc is caused by “sunlight going through ice crystals ...

Lunar rainbow: Ice crystals create subtle art . Witness Reporter. THE eerie sight of a Moon halo and Scorpio’s tail was captured on camera by reader Keith Fey in Hilton on Wednesday night.