Sundog and Hole Punch Over Wales

October 12, 2011

Moel y Ci sun dog - 20110805 - 02

Photographer: Graham A Stephen; Graham's Web site
Summary Author: Graham A Stephen; Jim Foster

These beautiful sunset cloud formations were complemented by the appearance of a striking parhelion, (or sundog), seen just above the horizon and to the right of the summit of the 1,345 ft (410 m) hill known as Moel y Ci. Sundogs are caused by sunlight refracting through hexagonal plate, ice crystals found in cirrus clouds. Dispersion of the rays passing through the crystals result in the "rainbow" colors. If the plate crystals wobble, the sundog will be noticeably elongated, as seems to be the case here.

Note also the curving distrail and hole punch cloud at center. A distrail is in essence the opposite of a condensation trail (contrail) -- we're seeing the path of the aircraft through the clouds rather than the contrail in a clear sky. Photo taken on  August 5, 2011.