WICKAPEDIA:
A sun dog or sundog (scientific name parhelion, plural parhelia, from "beside the sun"; also called a mock sun) is an atmospheric phenomenon that creates bright spots of light in the sky, often on a luminous ring or halo on either side of the sun.[1]
Sundogs may appear as a colored patch of light to the left or right of the sun, 22° (or more) distant and at the same distance above the horizon as the sun, and in ice halos
Sundogs are formed by plate shaped hexagonal ice crystals in high and cold cirrus clouds or - during very cold weather - by ice crystals called diamond dust drifting in the air at low level.
Sundog forming rays enter a near vertical prism side face of a crystal and exit through a second side face inclined 60° to the first. There is net refraction at each face and the light is dispersed into colors. There is no single angle of deviation through the crystal, which effectively acts as a 60 degree prism, but the minimum angle of deviation is ~22°. This corresponds to the distance of the inner edge of the sundog from the sun when the sun is low.[2]
As the sun rises higher the rays passing through the crystals are increasingly skewed from the horizontal plane. Their angle of deviation increases and the sundogs move further from the sun.[3] However, they always stay at the same altitude as the sun.
Sundogs are red colored at the side nearest the sun. Farther out the colors grade through oranges to blue. However, the colors overlap considerably and so are muted, never pure or saturated. The colors of the sundog finally merge into the white of the parhelic circle (if the latter is visible).
First Photo is by Isaac...He and I watched the Sundog
all morning...it would shift and change from faded to bright.
Two nights later we had a Blue moon
(that is two full moons in one month!)
A sun dog or sundog (scientific name parhelion, plural parhelia, from "beside the sun"; also called a mock sun) is an atmospheric phenomenon that creates bright spots of light in the sky, often on a luminous ring or halo on either side of the sun.[1]
Sundogs may appear as a colored patch of light to the left or right of the sun, 22° (or more) distant and at the same distance above the horizon as the sun, and in ice halos
Sundogs are formed by plate shaped hexagonal ice crystals in high and cold cirrus clouds or - during very cold weather - by ice crystals called diamond dust drifting in the air at low level.
Sundog forming rays enter a near vertical prism side face of a crystal and exit through a second side face inclined 60° to the first. There is net refraction at each face and the light is dispersed into colors. There is no single angle of deviation through the crystal, which effectively acts as a 60 degree prism, but the minimum angle of deviation is ~22°. This corresponds to the distance of the inner edge of the sundog from the sun when the sun is low.[2]
As the sun rises higher the rays passing through the crystals are increasingly skewed from the horizontal plane. Their angle of deviation increases and the sundogs move further from the sun.[3] However, they always stay at the same altitude as the sun.
Sundogs are red colored at the side nearest the sun. Farther out the colors grade through oranges to blue. However, the colors overlap considerably and so are muted, never pure or saturated. The colors of the sundog finally merge into the white of the parhelic circle (if the latter is visible).
First Photo is by Isaac...He and I watched the Sundog
all morning...it would shift and change from faded to bright.
Two nights later we had a Blue moon
(that is two full moons in one month!)
No comments:
Post a Comment