Washington State, June 3, 2006. "The Great Spokane
halo display" was
widely seen and will be remembered for the brightness and duration
of the arc. Jonathan Fox took this image when the sun was 64° high.
The halo lights the cirrus streaks with pure prismatic colours.
The circumhorizon and circumzenithal arc
colours are hardly smeared by ice crystal rotation and so are spectrally
pure, more so than those of the rainbow. Image ©Jonathan
Fox, shown with permission.