It occupies a roughly circular basin and covers an area of about 5,440,000 sq mi. Almost entirely landlocked, the ocean is surrounded by the land masses of Europe, Asia, North America, and Greenland and a number of islands, as well as by the Barents, Beaufort, Chukchi, Kara, Latev, East Siberian, Lincoln, Wandel, Greenland, and Norwegian seas. It is connected to the Pacific Ocean by the Bering Strait and to the Atlantic Ocean through the Greenland Sea. The topography of the ocean bottom is marked by fault-block ridges, plains of the Abyssal Zone, ocean deeps, and basins. The greatest inflow of water comes from the Atlantic by way of the Norwegian Current, which then flows along the Eurasian coast.
Water also enters from the Pacific via the Bering Strait.
The East Greenland Current carries the major outflow. Temperature and salinity vary seasonally as the ice cover melts and freezes. Ice covers most of the ocean surface year-round, causing subfreezing temperatures much of the time. The Arctic is a major source of very cold air that inevitably moves toward the equator, meeting with warmer air in the middle latitudes and causing rain and snow. Little marine life exists where the ocean surface is covered with ice throughout the year.