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. Marine life abounds in open areas, especially the more southerly waters. The Arctic Ocean is strategically important as the shortest route between North America and the Russia .