Sun Dog and Circumzenithal Arc Photographed by Eric Grieve

Eric Grieve — By pcburns on August 3, 2009 at 5:35 pm

A sun dog or sundog is a type of ice halo. It is a colored patch of light to the left or right of the sun. The circumzenithal arc is similar in appearance to a rainbow. It is caused by refraction of sunlight through horizontally-oriented ice crystals.

Sundog and Circomzenithal Arc - Click to Enlarge