also: きょっけん
noun
polar circle; polar region
Refers to the Arctic or Antarctic Circle, or the regions within them. Often used in compounds like 北極圏 (Arctic Circle) and 南極圏 (Antarctic Circle).
北極圏は北緯66度33分以北の地域です。
The Arctic Circle is the region north of latitude 66°33' N.
南極圏の気候は非常に厳しい。
The climate of the Antarctic region is extremely harsh.
Compound of 極 (pole) and 圏 (sphere, region). The reading きょくけん is the standard on'yomi combination; きょっけん is a less common variant.