Arcs Above Caen, France
October 06, 2012
Photographer: Rudolf Wehrung; Rudolf's Web site
Summary Authors: Rudolf Wehrung; Jim Foster
The photo above showing a bright circumzenithal arc (CZA) at top right as well as a dimmer and straighter strip of color at left center was taken from Caen, France. This fainter strip is an infrequently seen supralateral arc. Whenever a CZA is observed take a look for other arcs, such as supralateral arcs, in the same vicinity of the sky. Sunlight streaming through hexagonal, plate shaped ice crystals form CZAs. In order to see supralateral arcs, however, columnar crystals, having their long axes horizontal, must be present. Note that the Sun is behind the tree at bottom. Photo taken during the late afternoon of August 31, 2012.