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Parhelia (Sundogs)
Hy folks,
I´ve found something about Parhelia, or let´s better say the Sundogs (note there is more than one!!)
Maybe it _is_ a multi-cpu-card after all?...
see also this thread:
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Parhelia (Sundogs)
Crystal Orientation: Basal face horizontal
Ray Path: 3-7
Occurrence: very frequently
60-80 days per year
Parhelia appear to the observer as bright spots in the sky, one on either side of the Sun. The spots are situated on a line through the Sun parallel with the horizon. If the Sun is low, each is separated from
the Sun by an arc of 22°, and both lie on the 22°halo. As the Sun climbs higher in the sky, the parhelia move away from the 22° halo, although they remain on the line through the Sun parallel with the horizon. If the Sun's declination (angular distance above the horizon) is 40°, the parhelia are then seen 27.6°of arc from the Sun.
Parhelia frequently are very colorful. Hues of red lie toward the Sun. Fully developed, they have a long, white-blue tail extending away from the Sun parallel to the horizon. Parhelia are sometimes so bright
that observers are dazzled. Parhelia are caused by flat, plate-shaped hexagonal ice prisms. If these plate crystals fall unimpaired, drag forces automatically orient them horizontally. The more the ice crystals are oriented horizontally, the brighter the parhelia appear to be. Frequently the parhelia are visible while the 22 °halo is not visible. This phenomenon is observed when almost all the ice crystals are oriented horizontally, and few are
oriented at other angles. There is an interesting relationship between parhelia and the circumzenith arc. Both are caused by horizontally aligned plate crystals. Therefore one can say that if parhelia are visible there is a good chance to see the circumzenith arc, particularly when the sun's declination is between 15°and 25°.
I´ve found something about Parhelia, or let´s better say the Sundogs (note there is more than one!!)
Maybe it _is_ a multi-cpu-card after all?...
see also this thread:
----------------------------
Parhelia (Sundogs)
Crystal Orientation: Basal face horizontal
Ray Path: 3-7
Occurrence: very frequently
60-80 days per year
Parhelia appear to the observer as bright spots in the sky, one on either side of the Sun. The spots are situated on a line through the Sun parallel with the horizon. If the Sun is low, each is separated from
the Sun by an arc of 22°, and both lie on the 22°halo. As the Sun climbs higher in the sky, the parhelia move away from the 22° halo, although they remain on the line through the Sun parallel with the horizon. If the Sun's declination (angular distance above the horizon) is 40°, the parhelia are then seen 27.6°of arc from the Sun.
Parhelia frequently are very colorful. Hues of red lie toward the Sun. Fully developed, they have a long, white-blue tail extending away from the Sun parallel to the horizon. Parhelia are sometimes so bright
that observers are dazzled. Parhelia are caused by flat, plate-shaped hexagonal ice prisms. If these plate crystals fall unimpaired, drag forces automatically orient them horizontally. The more the ice crystals are oriented horizontally, the brighter the parhelia appear to be. Frequently the parhelia are visible while the 22 °halo is not visible. This phenomenon is observed when almost all the ice crystals are oriented horizontally, and few are
oriented at other angles. There is an interesting relationship between parhelia and the circumzenith arc. Both are caused by horizontally aligned plate crystals. Therefore one can say that if parhelia are visible there is a good chance to see the circumzenith arc, particularly when the sun's declination is between 15°and 25°.
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