Polar regions

Lore & Background

The polar regions, known as the frigid or polar zones, are Earth’s polar ice caps surrounding the North and South Poles, lying within the polar circles. These high-latitude areas are dominated by floating sea ice covering much of the Arctic Ocean in the north, and by the Antarctic ice sheet on the continent of Antarctica and the Southern Ocean in the south. The Arctic has several definitions, including the area north of the Arctic Circle, north of 60° north latitude, or from the North Pole south to the timberline. The Antarctic is usually defined as south of 60° south latitude, or the continent of Antarctica, as used in the 1959 Antarctic Treaty. These regions receive less intense solar radiation because the Sun’s energy arrives at an oblique angle, spreading over a larger area and traveling a longer distance through the atmosphere, where it may be absorbed, scattered, or reflected. Earth’s axial tilt of 23.5° most affects polar climate, but even in summer the high latitude prevents sufficient compensation of the Sun’s rays except near the polar circles. The large amount of ice and snow further reflects and weakens the already weak sunlight, contributing to extreme cold. Polar regions are characterized by extremely cold temperatures, heavy glaciation where precipitation allows permanent ice, short cold summers, and extreme daylight variations—twenty-four hours of daylight in summer and complete darkness at mid-winter. The northern polar region hosts many settlements, with countries including the United States (Alaska), Canada, Denmark (Greenland), Norway, Finland, Sweden, Iceland, and Russia claiming Arctic areas. Arctic circumpolar populations, though small, often share more commonalities with each other than with populations within their national boundaries, making the region diverse in human settlements and cultures. The southern polar region has no permanent human habitation; McMurdo Station is the largest research station, with others like Palmer Station, Amundsen–Scott South Pole Station, Esperanza Base, Marambio Base, Scott Base, and Vostok Station. While no indigenous human cultures exist, a complex ecosystem thrives, especially along Antarctica’s coasts, where coastal upwelling provides nutrients for krill, which feed creatures from penguins to blue whales.

Reader's Guide

The polar regions are significant as Earth's coldest and most extreme climatic zones, shaping global weather patterns and hosting unique ecosystems. In the north, diverse human settlements and cultures exist across countries with Arctic claims, including the United States, Canada, Denmark, Norway, Finland, Sweden, Iceland, and Russia. The southern polar region has no permanent human habitation but supports a complex ecosystem, particularly along Antarctica's coastal zones, where upwelling nutrients feed krill, which in turn sustain penguins, blue whales, and other creatures. Research stations such as McMurdo Station (US), Esperanza Base (Argentina), Scott Base (New Zealand), and Vostok Station (Russia) provide scientific study of this remote area.

Did You Know?

• The Arctic has various definitions, including north of the Arctic Circle (66°33'44" N) or north of 60° north latitude.
• The Antarctic is usually defined as south of 60° south latitude or the continent of Antarctica.
• McMurdo Station is the largest research station in Antarctica, run by the United States.
• Coastal upwelling in Antarctica provides abundant nutrients that feed krill, which in turn feed penguins and blue whales.