What is the Arctic?
The Arctic is the Earth’s northernmost region. Mostly comprised of ocean, the Arctic can be defined in many ways. Among them:
Arctic Circle
An imaginary line around the Earth at 66° 33’ N above which the sun does not completely set on the summer solstice.
Polar Treeline
The northernmost limit above which trees don’t grow.
Temperature
The areas at high latitudes where the average summer temperature does not rise above 10°C (50°F).
Politics
Various geographical boundaries set by the eight nations with territory in the Arctic.