Mackerel Sky Over Duluth, Georgia
July 25, 2007
The photo above shows a beautiful "mackerel" sky over Duluth, Georgia. A sky having this appearance is so named because seafarers of long ago though that close banding in cirrocumulus clouds resembled the scales on a mackerel. Cirrocumulus clouds are composed of ice crystals and form at high altitudes (greater than about 15,000 feet or 4,572 m). They're often, but not always, aligned roughly parallel to the direction of the wind. Photo taken on December 3, 2006. See also the Earth Science Picture of the Day for November 11, 2005.