Cape
Cod, Massachusetts Halos imaged by Jim Kirk September 1, 2006. ©Jim
Kirk,
shown with permission.
The sun is 52° high and thin cirrus
produces a spectacular and rare halo display. This image from Jim
Kirk's extensive series of photographs shows a sundog far from the
conventionally thought of 22° distance from the sun. It remains
at the sun's altitude and on the parhelic circle
but lies beyond even the bright circumscribed halo.
Sunlight has to internally reflect an even number of times from the upper
and lower basal faces of plate crystals to produce sundogs at these high solar altitudes.
Look carefully for faint arcs extending from the sundog towards the
circumscribed halo. these are not Lowitz arcs
but rare high sun Parry arcs.
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