1 文書を見つけるための辞書。

• arctic circle
• 北極圏限界線, 北極圏
• a line of latitude near but to the south of the north pole; it marks the northernmost point at which the sun is visible on the northern winter solstice and the southernmost point at which the midnight sun can be seen on the northern summer solstice
• 北極に近いが南の緯度の線