MOSAiC Expedition: An Arctic Odyssey of Climate Scientists

Since Captain Cook’s time (the collier bark Endeavor was the first scientific research vessel in history) ship expeditions have been extremely influential to understand our world. In an age of anthropogenic climate change the Arctic has remained the most understudied component of the global circulation system. Human induced global warming is exerting its effects on both poles of the planet.

Now the time has come and the international Arctic drift expedition known as MOSAiC Expedition (Multidisciplinary drifting Observatory for the Study of Arctic Climate) has set sail via the research vessel RV Polarstern with 600 scientific crew members from 17 countries on board. The project was in the making since 2011.

The expedition lasted 13 months and the crew stayed in the Arctic for the whole winter of 2019-2020. The RV Polarstern will be locked in ice and will drift. The idea is not new. In 1893, the Norwegian explorer Fridtjof Nansen deliberately let his wooden ship, the Fram, froze into the drifting sea ice north of Siberia. In this way rather than struggling to move on the ice, he and his team would drift towards the North Pole. The shifting pack of ice had carried the Fram some 2000 kilometers across the Arctic to the open North Atlantic Ocean over 3 years. Despite the fact that he could never reach North Pole, the experience revealed flow patterns that move heat, water, and ice across the Arctic Ocean which we now call transpolar drift stream.

The animation above visualizes transpolar drift stream (purple arrows) that carries freshwater runoff (red arrows) from rivers in Russia across the North Pole and south towards Greenland. A study published in 2012 showed that under changing atmospheric conditions, a new emergent circulation pattern (blue arrows) carry freshwater runoff east towards Canada, resulting in freshening of Arctic water in the Canada Basin.

The scientists of the MOSAiC expedition will carry out “in situ” measurements to fine tune parameters to understand phenomena including polar amplification. The Arctic is experiencing the fastest climate change (arctic amplification). Loss of sea ice and loss of reflectance (albedo) exposes dark sea to absorb more of the incoming sun rays which reinforces and speeds up warming. The thickness of sea ice especially what is going on underneath is rather hard by remote sensing.

Expectations are high from the $134 million MOSAiC Expedition and there has been quite a few significant revelations already from the very beginning of the data collection. These include the aerosol content of the Arctic winter atmosphere which is a determinant of physical qualities if clouds blanketing the area and the actual thickness of the sea ice which appeared to be overestimated through satellite measurements in the past. We have been dumping a lot of carbondiokside into the atmosphere leading to a cascade of environmental problems including ocean acidification. Atmospheric CO2 levels are rising fast. In fact, you can check the most up to date atmospheric CO2 reading from Hawaii yourself. If the carbon absorption rates of the twilight zone biota is impeded we may experience even greater levels of run-away greenhouse effect which causes global warming.