The largest Arctic expedition in history came to an end on Monday as the research vessel Polarstern returned to her homeport in Bremerhaven, Germany, more than a year after setting out on a groundbreaking—or more accurately, ice-breaking—polar voyage.
Since its departure from Norway on September 20, 2019, Polarstern has served as the wandering centerpiece of the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, which involved hundreds of researchers from around the globe.
During the ambitious journey, scientists captured a rare firsthand glimpse of the effects of human-driven climate change on the Arctic, which is warming at least twice as fast as the rest of the world. Markus Rex, an atmospheric scientist at Alfred Wegener Institute in Bremerhaven, warned that the trip revealed a “dying” Arctic ocean in a Monday press conference.
“The Arctic is really this central place for climate change,” said Matthew Shupe, an atmospheric scientist at the University of Colorado and a co-coordinator of MOSAiC, in a call. “The ice is declining very fast.”
“We need to understand the Arctic in order to understand how it is playing along with the rest of global change,” he added.
In addition to the expected challenges of such a trip—such as curious polar bears and months of sunless winter—the crew also experienced a scary brush with Covid-19, though fortunately nobody onboard was infected. The close call came in March, after a team member tested positive for Covid-19 shortly before they were due to travel to the ship.
The rigorous measures put in place to prevent transmission of the virus to Polarstern caused frustrating delays and complications for many research projects. Ultimately, though, the precautions proved successful in keeping the crew safe for the duration of the expedition. Given that the crew lived and worked in close quarters, it would have been challenging to stop an outbreak if an infected person ended up onboard the ship.
MOSAiC was inspired, in part, by the pioneering journey of the Norwegian explorer Fridtjof Nansen who, in 1893, deliberately allowed his wooden ship Fram to be frozen into the Arctic ice pack. Once it was locked into place, Fram drifted with the sea ice across the Arctic for three years, proving that vessels could use the frigid landscape as a means to chart this remote but influential region of our planet.
MOSAiC marks the first time that a modern research icebreaker has ever repeated this “drift” strategy across Earth’s northern pole cap.
Polarstern became encased in an ice floe off the coast of Siberia by October 2019, which carried her past the North Pole. The crew was released from the ice for the last time in September, in the waters off the coast of Greenland, before heading back to Bremerhaven.
“We’re peeling back the layers right now; unpacking the ship that has just been crammed full of all kinds of great science equipment and great scientists,” Shupe said. “I think, for myself at least, it’s a little bit bittersweet.”
“Of course, we’ve put so much effort into this field program and now that part is done,” he continued. “It feels like: ‘Boy, what am I going to do next? How am I going to define my life next?’ Because this has defined my life for so many years.”
Nansen may have been the first to successfully drift across the Arctic ice pack, but the MOSAiC crew had far more resources at its disposal, thanks to more than a century of scientific and technical advances. The price tag for the expedition totaled about $154 million, and was funded by the German Federal Ministry of Education and Research and the U.S. National Science Foundation and Department of Energy.
The expedition benefitted from the use of helicopters and aircraft, a fleet of support vessels sourced from Germany, Russia, and China, and a complicated suite of instruments designed to study Arctic sea ice dynamics, ecological systems, and oceanic and atmospheric processes.
“As we go forward in time, that's where it gets interesting for MOSAiC because it’s more than just my project, or someone else’s project,” Shupe said. “We designed it all together for all these projects to actually interact and cut across the system in really complex ways. Putting together the pieces is where it gets good.”
Shupe specializes in the complicated energy transfers that occur between the Arctic atmosphere and surface, but that represents only one tessera in this broader mosaic of niches that inspired the expedition’s acronym.
One of the biggest endeavors for the team, from here on out, will be calibrating climate models with the enormous volumes of new “process level” data collected directly from this rarely visited part of the world.
“That’s really the foundation of why we’re there, to collect this data and to turn it into knowledge that we can then use to develop and improve models,” Shupe said. “In the end, models are going to tell us about the climate in the future, models are going to be used to predict the weather, and we need those models to faithfully represent what is happening in the Arctic.”
“You have to go there with all these people and all this sophisticated equipment in order to get that kind of information,” he noted. “That’s what we’ve done with MOSAiC.”