In 1893, Arctic explorer Fridtjof Nansen deliberately lodged his wooden ship in the sea ice north of Siberia, hoping that its natural drift would take him to the North Pole. Though the Norwegian scientist failed to reach his desired destination, his three-year-long, 2,000-kilometer journey into the North Atlantic Ocean revealed important data about the then-mysterious Arctic Ocean. Now, an international team of researchers have embarked on a similar journey for a groundbreaking climate change study of the Arctic.
The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition began in Tromso, Norway, in late September 2019. The team's first challenge was finding a suitable floe to moor their research vessel — German icebreaker Polarstern. The ice sheet had to be both strong enough to drag the ship and wide enough to accommodate a landing strip for research and emergency airplanes. It took a few days, but by October 4, 2019, they had identified a 2.5-by-3.5 kilometer (about 1.5-by-2.2 mile) sheet that could do the job. "It may not be the perfect floe, but it's the best one in this part of the Arctic, and offers better working conditions than we could have expected in a warm Arctic summer," said expedition leader Markus Rex of the Alfred Wegener Institute for Polar and Marine Research.
Carried by the floe's drift, the Polarstern will now make its way across the Arctic Ocean at a leisurely pace of 7km/hr, allowing MOSAiC researchers to record scientific data and test theories about the impact of global warming. For example, it has long been suggested that the phytoplankton population has dramatically increased due to the warmer Arctic water. However, the assumption “is based on remote sensing [only] during the ice-free period. And we don’t have such observations from the central Arctic,” says Rolf Gradinger, who is leading the expedition’s ecosystem team. MOSAiC's year-long observations will help determine if that is indeed the case. The team will also use snowmobiles and helicopters to establish a network of autonomous research stations on the ice to collect additional climate data.
The Polarstern will be refueled and restocked with food and supplies by four different icebreakers at about three-month intervals starting December 2019. The boats will also bring in new teams of scientists and crew members and take back those whose three-month stints are done. All in all, 600 scientists from 19 countries will get a chance to conduct research on this historic $150 million expedition.
The climate change study is fraught with risk for the researchers involved. Over the course of the year, the floe could be damaged by a storm, leaving the ship stranded. Should that happen, Rex says the researchers will have to wait for it to consolidate into a stable floe again. His bigger fear, however, is of the ice cracking while team members are working on the surface, which could prove deadly.
The scientists will also have to keep a watchful eye for polar bears and get accustomed to the 150-day long "polar night" — from September to April — during which the sun will never rise. Cruise leader Christian Haas says to understand why the Arctic is warming at twice the rate as the rest of the globe, it is crucial to record data through all four seasons. He explains, "As the ice gets older, it's important to understand the interplay between winter freezing and summer melting, so we can judge whether the ice is getting thicker or thinner."
Similar to Nansen's epic journey, the researchers have no idea where the Polarstern will be when the expedition ends in the fall of 2020. Statistical calculations of the sea-ice drift indicate they might end up near the North Pole, or in the Fram Strait between Greenland and Svalbard. However, Rex, who will be on the ship for 10 of the 12 months is not concerned. The researcher says, "We will go and do science wherever the ice might carry us."
Resources: mosaic-expedition.org,nature.com,sciencemag.org
