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What are sundogs and how are they formed?

Dec 28, 2022 11:17AM ● By Content Editor
Photo: Kerry Seitz via KARE 11 News

By Alexandra Simon - KARE 11 News - December 20, 2022

On a cold morning in Minnesota, you might see what looks like a halo around or mini rainbows around the sun. 

Those are called sundogs, and they happen when light refracts through ice crystals high up in the atmosphere.

Those crystals are shaped like hexagonal prisms and float down to the ground horizontally. When sunlight enters the crystals, the light is bent and creates mini rainbows about 22 degrees on the left, right, or both sides of the sun.

Red light bends less, and blue light bends more, so when you see a sundog, you'll notice that the red part of the rainbow is closer to the sun, and the blue part is on the outer side.

We see sundogs much more often in winter because of the colder temperatures, but it's still possible to spot them in the summer. KARE 11 meteorologist Ben Dery says that can happen when the temperatures in the mid and upper levels of the atmosphere are cold enough.


To read this original story and more news, follow this link to the KARE 11 News website.

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