Possible Clues:

• Frigid Zone boundary
• It contains an expanse of white and is enough to make art critic cancel
• Latitude between the South Frigid Zone and South Temperate Zone
• Area containing the South Pole
• No need to square anything in pole position way down south
• Line that encloses a continent
• South Pole area
• Ring up the world? Quite the opposite
• Where the midnight sun can be observed
• Northern boundary of the South Frigid Zone