Arctic Circle

Arctic Circle, imaginary circle on the surface of the earth at 66 1-2°N latitude, i.e., 23 1-2° south of the North Pole. It marks the northernmost point at which the sun can be seen at the winter solstice (about Dec. 22) and the southernmost point of the northern polar regions at which the midnight sun is visible.

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Arctic Circle

Parallel of latitude approximately 66°30′ north of the Equator that circumscribes the northern frigid zone. It marks the southern limit of the area within which, for one day or more each year, the sun does not set or rise. The length of continuous day or night increases northward from the Arctic Circle, mounting to six months at the North Pole.

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Arctic Circle

the imaginary circle round the earth, parallel to the equator, at latitude 66° 32ʹ N; it marks the northernmost point at which the sun appears above the level of the horizon on the winter solstice

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Arctic Circle [¦ärd·ik ′sər·kəl]

(geodesy)

The parallel of latitude 66°32′N (often taken as 66½°N).