A colorless rainbow isn’t a rainbow at all, Alaska park rangers said.
A curved beam of white light appeared over Glacier Bay National Park and Preserve in Alaska, photos posted by park rangers showed. It looks a lot like a rainbow, but that’s not what it is.
Park rangers said Tuesday, May 17, the light is a fogbow. It’s similar to a rainbow but has key differences.
“This phenomenon can be seen when traveling through a low-lying fog bank on an otherwise sunny day,” park rangers said. “Fogbows appear white in color because fog is made up of much finer water particles than rain.”
Fogbows are like “rainbow’s cousins,” EarthSky reported. They’re sometimes called white rainbows, cloudbows or ghost rainbows, according to the news outlet.
The smaller water droplets in fog are too weak to create the vibrant colors seen in rainbows, EarthSky reported.
The sun has to be at a low angle for a fogbow to form, according to the Farmers’ Almanac.
“This is the reason why fogbows are most commonly spotted in the mornings and evenings, or from high vantages that place the viewer above the fog, like on a mountainside, seaside cliff, or even from an airplane,” the Farmers’ Almanac reported.
Fogbows aren’t uncommon at Glacier Bay.