Better known as sundogs, ice halos, sunbows, tangent arcs, sun pillars, ring around the moon and moon dogs, these refractions of sunlight on ice crystals in a cold stratosphere have a large and interesting family of effects and can be truly beautiful.
Ranging from subtle yellowish and blue colored tints around a bright moon to powerful and clear Roy G. Biv (red orange yellow, green, blue indigo and violet) color bands twenty two degrees on either side of a low angle sun. From faint rainbow colored rings around the sun in a hazy sky, to fantastic geometric shapes, crosses and inverted arcs traversing the sky, parhelia are some of the most interesting of all visual sky phenomenon.
Difficult to photograph and hard to predict, these wispy ice halos require some fairly rare atmospheric conditions to exist for them to be seen. Some, like the "sundogs," small rainbow colored bands commonly seen on either side of a late afternoon sun, are more familiar, while the inverted arcs, sky crosses, and tangent arcs require a whole host of conditions in the upper atmosphere to be just right in order for us to see them.
While small light refracting ice crystals are present in the upper atmosphere at all times of the year, the colder winter months and higher latitudes (lower sun angle) contribute to better sky watching. This calls for the "sundog patrol."
Sun pillars, that vertical shaft of light that is occasionally seen above a setting sun combined with a hazy cold sky, is perhaps one of the most spectacular parhelia effects because it is often seen in association with a colorful sunset. If you mix the colors of a beautiful winter sunset on the Pacific Ocean with the refractions from slowly falling microscopic-sized ice crystals above the sunset, the result can be fantastic.
The terrific light shows of parhelia, resulting from sunlight being refracted and or reflected from ice crystals, combined with a spectacular Aurora Borealis, can make for sky conditions that understandably have been connected with the spirit world in native cultures 'round the poles.
In a cold land where lightning and thunder are fairly rare, it doesn't take much to imagine our ancestors reckoning that the disposition of their various gods could be read in the colors of the sky and by the kind of weather that followed these "sky signs."
Much like sky signs today, if we see those same refracted rainbow colors coming from the ice crystals seeded high up in the the stratosphere, by say a B-1 bomber headed to Iraq, it follows then, that gasoline prices, will in all likelihood rise out of sight.
Sky ice in its many varied forms can produce some really breathtaking sights, so grab your camera, head out to a place with a clear view of the setting sun when high thin clouds appear, and maybe you'll get lucky and see the sky dogs towing the Inuit sun star down to the horizon.
Check out our new weekly Quicktime Mini-Movie on the web at: http://home.pacifier.com/~sparks/ wildlife!!.html.
Craig Sparks is the director of NAWA, and much prefers winter over summer. Found injured wildlife? Questions? Call NAWA at 665-3595 or send an e-mail to firstname.lastname@example.org.