Saturday, May 31, 2014

PARHELIA REVISITED – MORE ON SUN DOGS IN ROCK ART:


Sun sign with possible multiple parhelia. Three Rivers,
New Mexico. Photograph: 1988, Jack and Esther Faris.

On October 21, 2009, I posted a column which I entitled The Sun Paints His Cheeks – Sun Dogs. In that posting I wrote that “Parhelia would be expected to be portrayed in rock art as a sun sign with two or more spots added outside the perimeter of the sun sign. This example, which can be found at the Three Rivers petroglyph site in New Mexico, consists of the normal southwestern concentric circle sun symbol surrounded by a ring of 16 dots which may represent multiple parhelia (with a little exaggeration thrown in). In his book Rare Halos, Mirages, and Anomalous Rainbows and Related Electromagnetic Phenomena, William Corliss presents examples of multiple sun dogs with examples of up to eight cited. I would expect that a rock artist who had observed such an example of multiple parhelia could be motivated to reproduce it as a sun symbol surrounded by many dots, as in this example.” (Faris 2009) These optical effects are caused by light from the sun refracting through ice crystals in the atmosphere, and depending upon the conditions, the display can be quite complicated.



A combination of atmospheric optical phenomena in
the antarctic. Robert Greenler, 1980, Rainbows, Halos,
and GloriesCambridge University Press, London.

Robert Greenler has published photographs of many splendid displays of atmospheric optics in his wonderful book Rainbows, Halos, and Glories, (1980), and also included diagrams of drawings of these phenomena done in pre-photographic days, and also created in computer simulations. One example Greenler has published is Hevelius’s Seven Suns drawing of 1662, recording a drawing of a spectacular display he saw over Gdansk, Poland on February 20, 1661 (also known as Danzig under periods of German rule). In Hevelius’s drawing of this display: “the sun appears to be about 26 degrees above the horizon, and many of the elements of the drawing are familiar to us: the 22- and 46 degree halos, 22-degree parhelia, upper tangent arc to the 22-degree halo, circumzenithal arc, and parhelic circle. Hevelius shows as one of his suns the anthelion, which is surprising, but most unusual are the arcs crossing the parhelic circle about 90 degrees from the sun. These arcs are generally assumed to be part of a 90-degree halo that, from this report, is sometimes called Hevel’s halo.” (Greenler 1980:107)


Hevelius’s Seven Suns drawing,Gdansk, Poland, February 20,
1661. Robert Greenler, 1980, Rainbows, Halos, and Glories,
Cambridge University Press, London

In the copy of Hevelius’s drawing included in this posting I have added red circles to mark each of Hevelius’s so-called “Seven Suns” (including the real sun in the lower center) illustrating that a sun sign can indeed be surrounded by multiple dots in reality. Indeed, in such a complicated display, and with the multiple arcs, halos, and other effects intersecting each other, each area of intersection would show up as a larger bright spot leading to the possibility of many more “suns” visible at one time. 

W. E. Parry drawing, 1821. Robert Greenler, 1980, Rainbows,
Halos, and Glories, Cambridge University Press, London.

In a drawing by W. E. Parry from his 1821 Journal of a Voyage for the Discovery of a Northwest Passage, Murray, London, we see another amazingly complicated optical display. If we again assume that where each arc and halo intersect it can appear with the brightness enlarged and reinforced this display might have looked like the sun with as many as nine other suns around it. This can be seen in the Greenler photograph above which shows a complicated display in the antarctic.

Given this proof of interest in recording this phenomenon by 17th and 18th century western scientists I also have to assume that a Native American who viewed such a display might be just as eager to record his interpretation of what he had seen. The only question is how he would have interpreted it. This is one possibility of such, giving us, I submit, an excellent natural model for the sun signs surrounded by a ring of dots seen in rock art.

NOTE: If you are interested in generating atmospheric optical simulations to attempt to match rock art examples of your own check this web site to see HaloSim 3 downloadable software: http://atoptics.co.uk/halo/halfeat.htm.

REFERENCES:

Corliss, William R.
1984    Rare Halos, Mirages, Anomalous Rainbows and Related Electromagnetic Phenomena: A Catalog of Geophysical Anomalies, Sourcebook.

Faris, Peter
2009    The Sun Paints His Cheeks – Sun Dogs, http://rockartblog.blogspot.com, Oct. 21, 2009.

Greenler, Robert
1980    Rainbows, Halos, and Glories, Cambridge University Press, London.

Parry, W. E.
1821    Journal of a Voyage for the Discovery of a Northwest Passage, Murray, London.

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