Upper Tangent Arc Above Orsta, Norway

Provided by: Geir T. Øye
Summary authors & editors: Geir T. Øye, Jim Foster

The sporty upper tangent arc shown above was captured near sunset, on February 13, 2007, from Ørsta, Norway. Arcs tangent to the 22 degree halo are formed by pencil-shaped hexagonal ice crystals found in cirrus clouds. See also the Earth Science Picture of the Day for December 28, 2006.

Related Links:

• Geir's Web Page
• Atmospheric Optics
• Halos, Arcs, and Bows
• Color and Light in Nature