Circumzenithal Arc Over Southern New Jersey

November 02, 2008


Photographer: Lisa Gonnelli
Summary Author: Jim Foster, Lisa Gonnelli

This gauzy circumzenithal arc was photographed over Pilesgrove, New Jersey on September 17, 2008. Circumzenithal arcs are brightest when the Sun is about 22 degrees above the horizon. Many circumzenithal arcs have vibrant colors, although the wavy cirrus clouds shown above have dimmed this arc's coloration. Nonetheless, it's always fun to spy a stray strip of color somewhere in the sky. These arcs form only when sunlight enters through the upper basal faces of like-oriented plate-shaped ice crystals in the cirrus clouds and exits through one of the six vertical side faces.