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WEDNESDAY DECEMBER 13 - HALOS AND SUN DOGS
Of all the colors that the weather can produce in the sky, rainbows are probably the most
familiar, but they're not that common around here in winter. There are other colorful
displays to look for, two of which are
sun dogs. These form when sunlight
passes through a thin layer of ice clouds. The ice crystals act like tiny prisms,
breaking the sunlight up into colors.
As the name implies, a
halo is a complete ring around the sun. To create a halo,
sunlight has to pass through a fairly uniform and extensive layer of ice clouds.
To capture a halo on film, it's sometimes necessary to block out the sun using a
building or a
person, as seen in these photos.
If the clouds are more patchy, you
may not get a full ring, but rather just a splotch of colored light on one or both
sides of the sun. These are called
sun dogs. Their name is based on their position,
not their shape - you'll always find them in line with the sun, appearing to heel at
the side of their master.
To get a sense for how far sun dogs and halos appear from the sun, cover the sun with
your thumb, and stretch out your hand. The tip of your little finger will fall at
roughly the right distance from the sun.