The Arctic and the Arctic Ocean

The Arctic Ocean, which is the ocean in the Arctic, is the smallest and shallowest of the world’s five oceans. By area, around half of it is above the continental shelf, while the rest consists of deep sea basins, often around 3,000 metres deep. The Arctic Ocean is split into several basins by underwater ridges.

In the winter, most of the Arctic Ocean is covered by ice. In summer some of the ice melts, so ice cover is lower. Sea ice extent has fallen significantly in recent years, with the biggest declines being seen in summer. The ice has also become noticeably thinner. The proportion of old, multi-year ice, in other words ice that has survived at least one summer, is at a record low. One of the reasons for this reduction is the inflow of warm Atlantic water.

Water circulation in the Arctic Ocean largely follows the topography. From Svalbard, the Norwegian Current heads east along Siberia following the edge of the continental shelf. The current starts on the surface, but in due course it sinks below a layer of cold, fresh Arctic water. The heat brought by the Norwegian Current can be traced almost everywhere in the Arctic Ocean.

The water in the central Arctic Ocean is highly layered, and it contains few nutrients. Consequently, there are few animals or plants in this part of the ocean. Most life is found above the continental shelves and along the ice edge. That is where you find ice algae, zooplankton, ringed seals and polar bears.