by Diane Walsh

Created on: August 11, 2008

Mother Nature's Dogs

Combining the sun with ice crystals seems like an impossible task, but leaves it to Mother Nature to produce yet another beautiful image on her atmospheric canvas. One of these images is called a "sun dog" or "mock suns."

Sun dogs are bright white bursts of light, or can be colored spots caused by the precise combination of ice crystals, atmosphere conditions, refractions and sun light. They usually appear in pairs, one to the right of the sun and one to the left.

Ice crystals in the sky forms many, many ice mirrors. These "mirrors" reflect the sun's rays and the earth's atmosphere to form visual images. Water freezes in the atmosphere and produces ice crystals. The ice crystals form in many different shapes. The refraction of light on a six-sided hexagonally shape or stop sign shaped ice crystal is used to make a sun dog. These ice crystals fall to the ground near sunrise and sunset. Sun dogs appear when the sun is near the horizon and when the sky is saturated with ice crystals.

Water droplets falling from the ice crystals reflect the sun's rays in many directions. The rays bounce off the inside of the droplets many times and many ways before exiting. This ping pong effect of light dancing combined with the atmosphere produces sun dogs.

The atmosphere must be filled with cirrus clouds. The cirrus clouds trap and reflect the sun's rays. Cirrus clouds are made of heavy ice crystals. Ice crystals can also be produced from the frozen exhaust from air planes. The atmosphere gets filled with ice crystals making the conditions favorable to form sun dogs.

Sun dogs were recorded in Ancient Egypt has a day with two suns. The Greeks recorded the sun dogs as "mock suns," and always at the side of the sun, never above or below it. The Greeks were the first to use the sun dog as a weather predictor. This could be true, because cirrus clouds are known to produce precipitation. Many cirrus clouds may be a sign of a frontal system.

Sun dogs can appear at any time of the year, but are closest to the sun during the winter months. This is because the sun is lower in the sky and ice crystals are more abundant.

Sun dogs are the second most frequent display of the sun and her images. The halo phenomena or the 22o halo is the first. The major difference between the forming of the two is the shape of the ice crystals. Elongated and flat crystals are used to form other images.

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