Sundog (noun, soon derg)
Sundogs are bright flares of light that appear on either side of the sun in the sky. They form when incoming sunlight bends or refracts off small prismatic ice crystals in the atmosphere.
The angle within these six-sided ice crystals causes Sundogs to appear 22 degrees away from the sun in the sky. Sundogs can appear singly or in pairs on either side of the sun or on the halo orbiting the sun. It can also occur on nights when the moon is bright. These are known as moondogs.
Sundogs often have colorful rainbow-like stripes. That’s because the white light from the sun is made up of different wavelengths and colors of light. And those light waves bend at slightly different angles from the ice crystals in the air. This separates the incoming sunlight into the colors of the rainbow. But unlike a rainbow, where the outer edge is always red, the red appears on the inside of the sundog, closest to the sun. Blue appears on the outer edge of the sundog furthest from the sun.
Sundogs only appear when the sun is fairly low in the sky. When the sun gets too high, the sunlight doesn’t hit the ice crystals at right angles. Sundog disappears because light cannot be refracted in a way that we can see. Sundogs occur most often when temperatures are cold, but they can also occur when it’s not freezing. As long as there are ice crystals in the atmosphere, they can appear anywhere on Earth. This often happens with thin, high-flying cirrostratus clouds. The appearance of those clouds can indicate that rain is on the way.
in one sentence
If people spot sundogs or moondogs, there is a good chance of precipitation within the next 24 hours.
Check out the complete list ofscientists say.
Source: www.snexplores.org
