In the skies above Florida’s Key West yesterday morning, the unusual phenomenon of a ring around the Sun could be seen, which seems to have first been sighted and officially called in by a dawn-treading sailor.
Some people who have viewed the rings, mock suns, sun dogs, or other related atmospheric phenomena have wondered if there were "some strange rays" being given off by the Sun or the Moon.
NOAA tells us that the Sun-ring, typically a harbinger of forthcoming rains, is a ring of colored or white light seen to be encircling the Sun, or at other times colorful arcs or spots, when viewed through the lens of an ice crystal cloud formed of high-atmosphere cirrus occurring at least 25,000 feet above the surface of the Earth. The angle of observation needed is about 22°.
The Sun-rings can be formed of the refraction of either solar or lunar light and occur regularly on a global scale.
While a Sun-ring (or Moon-ring) does not have much to do with predicting snowfall in the Winter, in the Spring and Summer it is an accurate predictor of rains to arrive in approximately 12 to 18 hours. The cirrus clouds in question usually come before a warm front. The rain that is "predicted" to fall is usually going to be a long, slow rainfall.
There can occur, however, a different ring called a "great halo", and the great halo is much more rare, appearing at an angle of observation of 46° from the Sun or Moon. With the great halo, the refracted light enters the top of the ice crystals to emerge from one of the sides; it can also enter through the sides of the crystals and then emerge from their bottom sides.
Yesterday morning’s ring was pinkish in hue and was also, it turns out, entertaining the eyes of some early morning Florida Keys sunbathers, and it remained visible for about four hours into midday.
A skywatcher’s journal entry from nearly six years ago includes a great description of a previously viewed Sun-ring:
Oct. 24, 2002: It was just after lunch on Sept. 25th when I stepped out onto the rear deck of my home in Ohio. What a gorgeous autumn afternoon. The pale blue sky was streaked with wispy white cirrus clouds. The Sun was high and bright.
I glanced up….
The sun was surrounded by an extraordinarily bright, rainbow-colored halo. Flanking it both left and right were two brilliant, comet-shaped rainbow-colored sun dogs or mock suns (technically known as parhelia from Greek words meaning "beside the sun").