News

Actions

Did you see this over metro Detroit? Meteorologist Dave Rexroth explains

CORP-Digital-Default-Image-1280x720-WXYZ.png
Posted at 4:48 PM, Aug 01, 2017
and last updated 2017-08-01 17:11:01-04

It's a bird! It's a plane! It's a........ a halo?

It's no super hero, but it is super cool and more common than you might think.

The atmosphere is made up of all kinds of gases. The one that we see the most is water vapor in the form of clouds, fog, and precipitation. At high levels of the troposphere, the part of the atmosphere where are weather happens, it is cold enough to freeze some of that water vapor to make clouds out of ice crystals.

When the sun's light passes through these crystals it gets refracted, or bent like light through a prism. That refraction spreads out the different colors of sunlight so we see them all.

The most common forms of halos are sun dogs when the sun is low and full circular halos around the sun when it is high. The sun dogs happen when sunlight passes through frozen crystals in high clouds.  Rainbows happen when sunlight passes through raindrops and is refracted in the same way because of the prism effect of the raindrops.

The photos sent to us were taken at Farmington and I-96 in Livonia this afternoon by viewer Jason Dessert. The images do not show what is known as a sun dog, but just a small piece of a halo around the sun. It just happens that the right kind of ice cloud ( cirrus or cirrostratus) was in the right place (22 degrees from the sun) at the right time to make the sunlight spectrum visible. The sun is off camera, but is above the halo seen making it a small part of the bottom of the sun halo if we could see the entire thing.

A sun dog are more subtle looking "fake" suns on either side of the real sun along the 22 degree halo. They are the most common type of sun halo optical event and are best seen when the sun is low in the sky. The sun dogs are always located at the same altitude above the horizon as the sun.

Look around when you see high wispy clouds and you will be amazed at how common halos really are. Keeping an eye on the sky is a very cool thing! That's why we always do it.