Arctic environments

Definitions

The most popular definition of the Arctic includes all areas north of the Arctic Circle (latitude 66 1/2 °N). This is the latitude at which the sun does not rise in mid-winter or set in mid-summer. However, this simple definition excludes significant areas which are distinctly ‘Arctic’ in character and obscures the range of environments present within the Arctic. In fact, depending upon one's viewpoint, the definition of what constitutes the Arctic will vary.

From a climatic viewpoint, a relatively unambiguous definition of the Arctic is the region where the warmest monthly mean temperature does not exceed + 10°C and the coldest is below 0°C. The term Subarctic is then used to describe those areas where the mean monthly temperatures do not exceed + 10°C for more then 4 months and where the coldest is below 0°C. Together, the Arctic and Subarctic constitute what is sometimes termed the Circumpolar North .

The boundary between the Arctic and Subarctic, as defined above,...