Rochester, Minnesota Sundog

June 25, 2006

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Provided by: David Welsh
Summary authors & editors: David Welsh; Jim Foster

This eye-catching sundog was captured near sunrise on February 17, 2006 from near Rochester, Minnesota.

Sundogs are formed when light is refracted through the side faces of hexagonal, plate-shaped ice crystals -- most always in thin cirrus clouds. As viewed from above, sunlight entering a side face of a crystal is bent 22 degrees (toward an observer) as it exits an alternate face. For this dog, the crystals weren't all oriented in the same way, thus it's shape is somewhat elongated.

Photo details: Kodak DX6340 Digital camera, 5.6 mm focal length, .001sec. exposure, f/5.6 aperature.

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