REFRACTION OBSERVATIONS ON THE GREENLAND ICECAP

George Wallerstein

Peer Reviewed

Abstract:	During the summer of 1955 observations of refraction of the sun at low altitudes were made in Greenland. They were part of the program of icecap expedition Jello of the Snow, Ice and Permafrost Research Establishment that travelled from Thule east and then south on the icecap to the French Central Station at Latitude 70°55’ North, Longitude 40°38’ West. Although the location of the observations changed, they were always made over a snow surface which is generally extremely cold at night. This adds uniformity to the observing conditions which would otherwise not be present if the terrain varied. Observations were taken under all conditions in which the sun was visible, including thin clouds of various types and temperature inversions. Inversions must not be considered abnormal at night in the arctic and observations taken during inversions were not discarded. Pressure altitudes ranged from 1000 feet to 11,500 feet and temperatures from + 18°F to -21°F.
Published in:	NAVIGATION: Journal of the Institute of Navigation, Volume 5, Number 3
Pages:	138 - 140
Cite this article:	Wallerstein, George, "REFRACTION OBSERVATIONS ON THE GREENLAND ICECAP", NAVIGATION: Journal of The Institute of Navigation, Vol. 5, No. 3, 1956, pp. 138-140.
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