Circumhorizontal Arc Over Whiting, New Jersey

November 03, 2008

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Photographer: Paul Gitto, Arcturus Observatory
Summary Author: Paul Gitto

Some locales seem to get more than their fair share of atmospheric delights. Or perhaps, observers in some locations know just when and where to observe. Sky-gazers in southern New Jersey, particularly near the towns of Whiting and Pilesgrove, have been treated to some spectacular halos, sunsets and circumhorizontal arcs (CHAs) in recent months. The mesmerizing CHA shown above was captured on May 28, 2008 from Whiting. Though these stunning arcs can be viewed from many different parts of the globe, they’re seldom seen since the Sun must be at least 58 degrees in altitude (above the horizon) in order for them to form. They peak in brightness when the Sun is at 68 degrees in altitude. Whiting and Pilesgrove are both just shy of 40 degrees north latitude. The best days to observe CHAs at that latitude are from May 11 until July 31. On those days the Sun is greater than 68 degrees in altitude at noon. However, CHAs can still be seen from April 10 until August 30 when the Sun at noon attains an altitude of at least 58 degrees. For three days in a row, May, 28 - May 30, 2008, CHAs were visible over Whiting. More than their fair share indeed!