Foto: Alfred-Wegener-Institut/Stefan Hendricks
The ice-breaker Polarstern will be the base for the expidition and will be stuck in the Arctic Photo: Alfred-Wegener-Institut/Stefan Hendricks

The German-led expedition MOSAiC (Multidisciplinary drifting Observatory for the Study of Arctic Climate) is the largest Arctic expedition to date.

The MOSAiC expedition, led by the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) entails unprecedented challenges. The icebreaker Polarstern will be frozen in the ice for a year in the Arctic.

An international fleet of 4 icebreakers, whereof one is the Swedish Oden, helicopters and aircraft will supply the team on its epic voyage. A total of 600 international participants, half of which are researchers, will be part of the mission.

In rounds, they will be aboard the ship to research and collect data to better understand climate change.

On board the Polar Star there are chemists, biologists and physicists who will study the ice floe they will be drifting on. Around the ice floe, which is 1-2 km wide, there will be an electric protection field, preventing polar bears from entering. Temperature conditions are tough, in winter it can be -50 degrees in the Arctic.

Foto: Peter Sylvander
Pauline Snoeijis Leijonmalm in the Arctic during a prior expedition. Photo: Peter Sylvander

One of the researchers participating is Pauline Snoeijs Leijonmalm, professor of marine ecology at Stockholm University:

- We want to predict what the ecosystem will look like in 100 years. So far, it has mostly only been climate scientists who studied the Arctic. They have concluded that there will be major seasonal changes and that it will sometimes be completely ice-free there during certain periods of the year. This is why we now are stepping in to investigate the impact of these seasonal changes for wildlife, says Pauline Snoeijs Leijonmalm.

During the expedition, Pauline Snoeijs Leijonmalm will study everything from bacteria to fish. Plankton can be over 1 cm in the Arctic due to favourable conditions, unlike in the Baltic Sea, where they are only a few millimeters for example. Pauline will also study the Arctic cod that will drift with the ice foe, as it follows the annual cycle with its mating areas.

Markus Rex, Head of MOSAiC, Alfred Wegener Institute, Germany says:

- This mission is ground breaking. Never before has there been such a complex Arctic expedition.  For the first time we will be able to measure the climate processes in the Central Arctic in winter. And so for the first time we will be able to understand this region and correctly represent it in climate models. The Arctic is the epicentre of global warming and has already undergone dramatic changes. And it is the weather kitchen for our weather in North America, Europe, and Asia. Extreme weather conditions like outbreaks of cold Arctic air here in winter, or heat waves in summer are linked to the changes in the Arctic. At the same time, the uncertainties in our climate models are nowhere bigger than in the Arctic. There aren’t any reliable prognoses of how the Arctic climate will develop further or what that will mean for our weather. Our mission is to change that.

For Pauline Snoeijs Leijonmalm, that has been on expeditions in the Arctic since 2002, this is a dream expedition:

- After having heard about MOSAiC for the first time more than 5 years ago, I instantly knew deep in my heart: This is it! – and I started to dream about the wonderful scientific results that could be obtained during a full seasonal cycle in the Central Arctic Ocean. Almost everything we would discover would be totally novel – especially during the polar night and winter – the highest professional fulfilment a scientist can achieve.”

Facts about the expedition

  • The budget for the expedition is roughly 140 million euros.
  • During the course of the year, circa 300 researchers from 17 countries will be on board, from Belgium, Canada, China, Denmark, Finland, France, Germany, Great Britain, Japan, the Netherlands, Norway, Poland, Russia, Spain, Sweden, Switzerland and the USA.
  • They will be supported on land by researchers from Austria and South Korea.
  • The questions that the researchers will be investigating during the expedition are closely linked.
  • Together they will study the entire climate system in the Central Arctic for the first time.
  • They will gather data on five subareas: atmosphere, sea ice, ocean, ecosystems and biogeochemistry, in order to gain insights into the interactions that shape the Arctic climate and life in the Arctic Ocean.

More information

You can find the latest news from the Arctic via the MOSAiC channels on Twitter (@MOSAiCArctic) and on Instagram (@mosaic_expedition) using the hashtags #MOSAiCexpedition, #Arctic and #icedrift. There is more information on the expedition at: The MOSAiC web app allows you to follow Polarstern’s drift route live: