The Drift

Although the Arctic is considered the epicentre of global warming, scientists still have little knowledge of the Arctic climate system. Our understanding of its processes is very much limited by a dramatic lack of observations from the central Arctic, particularly in winter and spring. In these seasons the sea ice is so thick that even modern icebreakers get stuck, making this remote area inaccessible for scientific research.

The MOSAiC expedition joins international forces and provides the scientifically needed access to the Arctic. MOSAiC is inspired by an idea that the famous explorer Fridtjof Nansen had more than 125 years ago: letting nature be the navigator to cross the North Pole. By using the natural drift of the ice rather than fighting it, nature alone will dictate the research vessel Polarstern’s course, allowing a total of 300 researchers on board during different phases of the expedition to experience the Arctic winter close up.


Arctic sea ice mainly forms off the coast of Siberia – the region considered by some as the birthplace of the Arctic ice masses. From there, the ice drifts slowly across the Central Arctic and, after a year, is transported southwards via the Fram Strait east of Greenland to the Atlantic, where it eventually melts. This phenomenon is known as the Transpolar Drift. However, not all the Siberian ice takes the direct route toward the Fram Strait; some of it takes a route north of Canada and Alaska and becomes trapped in the Beaufort Gyre, where it can remain for several years. During this time, the ice develops into enormous ice floes.

In September 2019, when the sea ice is at its thinnest, Polarstern will sail to the Siberian coast to become locked in the ice. In addition, the ship will be moored to an ice floe that is at least 1.5 metres thick and several kilometres wide and which has enough room for a landing strip for planes and the central research camp.

Then the Polarstern's yearlong journey through the Arctic Ocean will begin.

Frozen into the ice and drifting with it, MOSAiC will observe the full annual cycle of the sea ice - including the atmospheric and oceanic processes that affect the sea ice as it evolves from new first year ice to multi-year ice and eventually towards its decaying stage as the ice approaches the North Atlantic sector.

Learn more about the complex logistics that make MOSAiC possible
See logistics
Read more about the science questions and research foci of MOSAiC
See science