Circumzenithal Arc Over La Seyne
November 25, 2004
The above photo of an especially colorful circumzenithal arc was captured above La Seyne-sur-Mer (southern France), this past September, at about 7:00 p.m (local time). The Sun was approximately 30 degrees above the western horizon, and the circumzenithal arc was perhaps 70 degrees above the horizon). Circumzenithal arcs, as is the case with all halo phenomena, owe their color to refraction in hexagonal ice crystals. In order to observe these majestic arcs, the Sun must be lower than about 32 degrees above the horizon.