The Arctic Circle (the circle of latitude running appoximately 66°30′ North of the Equator) is often considered to denote the southern limit of the Arctic. It is the dividing line for the sun’s rays. North of it, the sun does not set at night for at least part of the summer. Correspondingly, the sun remains below the horizon for part of the winter.
Botanists define the Arctic by a lack of trees. Treeline (also known as timberline) is the latitude beyond which trees do not grow. Treeless tundra occurs north of the timberline.
The boundry of the Arctic defined according to climate encompasses an area where the average temperature in the warmest month of summer does not exceed +10°C.
The geographical North Pole is the northern end of the earth’s axis of rotation. The latitude is 90°N. However there is no exact point as the axis wobbles slightly.
The magnetic North Pole is not located at the exact same place as the geographic pole is but further down in North Canada. However, it is not a fixed point. Since its discovery, it has moved from about 1000 km. Every year, it moves away for about 40 km.
The sun rays reflecting from the snow and ice are dazzling in the Arctic regions, which can result in snow blindness.
Snow blindness is the body’s protective mechanism against dangerously strong ultra-violet radiation. The reaction protects the cornea from damage. The symptoms are pain and dimmed vision; they disappear over time. People have traditionally protected themselves from strong solar radiation by using different protective glasses, particularly in snowy conditions.
Source: Arctic Museum Rovaniemi