Wednesday, June 11, 2014

Bellingham, 12:53 pm

On the drive down from Mount Baker, I saw a good example of a 22º halo, an optical phenomenon caused by the refraction of sunlight by hexagonal ice crystals in a layer of cirrostratus nebulosus cloud. The inner edge of the halo is red and the outer edge bluish, though this could be seen more clearly with the naked eye than in the photo.

The 22º halo is actually a fairly common phenomenon, occurring up to 100 days a year in temperate latitudes. If you haven't seen it, it's probably because you are wise enough not to stare at the sun.