Sunday, December 8, 2013

sundogs


A sundog  is an atmospheric phenomenon that creates bright spots of light in the sky, often on a luminous ring or halo on either side of the sun.
Sundogs may appear as a colored patch of light to the left or right  in ice halos. They can be seen anywhere in the world during any season, but they are not always obvious or bright. Sundogs are best seen and are most conspicuous when the sun is low.  Prisms of ice form in the air and light is refracted by them.   Amazing.

The following is a science lesson that was e-mailed to me so I thought I would include it also.

There are some beautiful things about winter. Did you see the sundogs?

From Hal Borland's lovely book "Sundials of the Seasons":

"The snowflake and the ice crystals have their own symmetrical beauty, colorless as water; but a cloud of minute ice crystals flung across the eastern sky at sunrise on a frosty morning can produce sun dogs which are as colorful as rainbows and are sometimes mistaken for rainbow fragments in the wrong part of the sky. Sun dogs and rainbows are related, since both are caused by sunlight's being reflected and refracted from moisture in the air. The rainbow is sunlight broken down into the spectrum by the curved surfaces of raindrops; the bow is all the way across the sky from the sun. Sun dogs are sunlight broken into the spectrum by the prism surfaces of the ice crystals, and sun dogs are seen in the same area of the sky with the sun. The ice crystals are very small. They make up those cirro-stratus clouds which ride high in the sky ahead of a Winter storm center. Sun dogs (and moon dogs) are as beautiful accents to a Winter day or night as the rainbow is to a showery Summer day."

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