Fire Rainbow Spotted In Avalon, New Jersey Over Memorial Day Weekend
AVALON, N.J (CBS) – A fire rainbow was spotted on a Jersey Shore beach over the holiday weekend. A beachgoer in Avalon posted a photo of a "Fire Rainbow" on Twitter Sunday.
This type of scene is an optical phenomena that falls into the same category as others such as ice halos, light pillars and sun dogs.
The scientific name of this phenomena is "circumhorizontal arc." The term "Fire Rainbow" is a bit misleading as this particular phenomena is not related to fire nor rainbows.
In its full form, the arc has the appearance of a large, brightly spectrum-colored band, running parallel to the horizon.
This optical phenomena forms when sunlight passes through high-level clouds, known as cirrus clouds, which are composed of tiny ice crystals. As the light passes through, it's scatted and creates a cloud iridescence.
"The halo is formed by sunlight entering horizontally oriented, flat hexagonal ice crystals through a vertical side face and leaving through the near horizontal bottom face," CBS3 meteorologist Matt Peterson explained. "The ice crystal acts as a prism, separating the white light into its various colored components."
How often a circumhorizontal arc is seen depends on location and latitude.
Peterson says it's a relatively common halo in the United States that is seen several times each summer in any one place, but it is a rare phenomenon in Northern Europe.
The halo requires that the sun be very high in the sky, at an elevation of 58 degrees or greater.
"This means that the solar variety of the halo is impossible to see at locations north of 55 degrees north," Peterson said. "The arc has a considerable angular extent and thus is rarely complete."
When only fragments of a cirrus cloud are in the appropriate sky and sun position, they may appear to shine with spectral colors, as shown in the photo.
