Arctic means near the Bear—and less than fifty centimetres of snow
Earth's north polar region above the Arctic Circle takes its name from Greek arktos, bear, via the prominent northern constellations. Tundra, permafrost, and seasonal sea ice dominate. Precipitation is mostly snow and often under 50 cm yearly, though wind-blown drifts fake heavier falls.
Where the Arctic ends depends on who is drawing the line. One boundary is the Arctic Circle at about 66°34′N, roughly the southern edge of the midnight sun and the polar night. Ecologists prefer a climate test: places where July, the warmest month, averages below 10 °C, a line the northern treeline closely tracks. Because warming has pushed temperature bands poleward by about 56 km per decade over the past 30 years, the region defined that way is shrinking. The Greek root refers either to the Great Bear or to the Little Bear, the constellation holding the celestial pole near Polaris.
Winters average as low as −40 °C, and the coldest reading is about −68 °C. Coasts are milder and snowier than the dry interior. Plants hug the ground as dwarf shrubs, sedges, mosses and lichens; in the warmest pockets shrubs reach 2 metres, while the coldest ground is largely bare. Arctic hares, lemmings, muskoxen and caribou feed snowy owls, foxes and wolves, some 200 bird species breed there, and narwhals, belugas and walruses patrol the seas. The region also holds a fifth of Earth's water. Models disagree on timing, but they project summer sea ice could vanish in September sometime between 2035 and about 2067.
Dinosaurs knew this place too. In the Cretaceous, animals like Edmontosaurus and Troodon may have migrated north for the summer growing season, though some researchers think dinosaurs lived year-round near Alaska's Colville River. The first people of the central and eastern North American Arctic, the Arctic small tool tradition, appeared around 2500 BCE, followed by the Dorset. Thule ancestors of the Inuit, descended from Siberia's Birnirk, replaced the Dorset completely after 1300 CE and settled Greenland.
The eight Arctic nations sit on the Arctic Council beside six Indigenous organizations, working by consensus mostly on environmental matters. No country owns the North Pole, and since 1 January 2017 a polar shipping code has covered vessels over 500 tonnes in Arctic waters.
Source: Arctic
