Credit: Michael Gutsche

When scientists were planning MOSAiC — an epic research expedition that would remain trapped in Arctic sea ice for one year — they considered the North Pole’s hazards. They worried about hypothermia, isolation, crushing ice and polar bears. They had dozens of contingency plans. But no one anticipated a pandemic.

The travel restrictions and flight cancellations imposed because of the coronavirus outbreak have now forced mission planners to make a seemingly impossible decision. Polarstern, the German research vessel central to the expedition, will temporarily leave its position in the ice to exchange its crew, and so will be forced to abandon the research camp where it has been frozen since October.

The disruption is a blow to the mission’s researchers, who have created a unique platform from which to study climate change in the Arctic, with a data due to be collected continuously over an entire year. Although they hope to refreeze the ship at the same camp after a three-week pause, the interruption will leave a hefty gap in the data set — and potentially miss a crucial time for data collection as Arctic ice begins its springtime melt.

“Ideally, we would not leave the ice — but given all the circumstances, I think it’s amazing we were able to come up with a solution to continue the experiment,” says Donald Perovich, a geophysicist at Dartmouth College in Hanover, New Hampshire, and a member of MOSAiC’s project board.

Close quarters

The news will come as a relief to the scientists and crew who have had to grapple with the uncertainty of having no return date. The travel stoppages have left the crew stranded since early April, when flights in and out of the Norwegian islands of Svalbard were meant to have swapped the ship’s researchers. “That put them in a much more difficult place psychologically,” says Allison Fong, a polar biologist at the Alfred Wegener Institute in Bremerhaven, Germany, and a co-leader of MOSAiC’s ecosystem team.

So MOSAiC coordinators have been working tirelessly to find an alternative plan. But because the coronavirus pandemic has forced airports, military facilities and seaports worldwide to shut down, it has not been easy. The only solution requires Polarstern to fire its engines, break free from the ice and travel to a fjord in Svalbard. There, it will rendezvous with two other ships to swap scientists before returning to the Arctic research camp in roughly three weeks. (That timeline could change depending on the weather and ice conditions.)

“The idea of leaving the camp and floe was certainly not something we would have considered in the original rotation plan,” Fong says. “But given what we’re encountering now, I think it’s an important compromise that recognizes that the human dimension to the work we do is very, very important.”

The pandemic also means coordinators are using meticulous precautions to ensure that no one carries the virus to the ship. The next rotation of scientists will arrive in Hamburg, Germany, on 1 May and go to Bremerhaven by private bus. There, they will be tested for the virus before going into individual quarantine. Assuming everyone is negative, they will undergo safety training in group isolation. After two weeks, they will travel to Svalbard on two German research vessels and board Polarstern before it returns to the research camp.

Mind the gap

Although scientists plan to leave the research station mostly intact, certain measurements will have to stop. The remotely operated vehicle that dives into the ocean twice a week will be pulled out of the water. The tethered balloon that monitors the atmosphere will be packed away. And the scientists’ continuous collecting of ice and snow samples across the floe will stop.

“We’re going to do the best we can with these constraints,” says Matthew Shupe, an atmospheric and oceanic scientist at the University of Colorado Boulder and co-leader of MOSAiC. “But in the end, it’s a bummer.”

That is especially true, given that the gap will probably hit during a crucial time: when the ice begins to melt. Every spring, melting exposes dark ocean water, which absorbs more sunlight than does the ice. That warms the ocean further and spurs more melt in a vicious cycle that scientists are eager to study in detail.

It’s also when life in the Arctic flourishes. As sunlight penetrates farther into the ice and upper ocean, sea-ice algae and phytoplankton form massive blooms that provide meals for the rest of the Arctic food web. It has never been studied before in the central Arctic. Now scientists might miss it.

But there are a number of autonomous research stations on the ice that will continue to function, taking measurements of, for example, wind speed, temperature, pressure and humidity. Optical sensors measure how much sunlight is transmitted into the ocean and how much is reflected off the surface. And ocean sensors monitor chlorophyll — a proxy for biological activity.

“It’s the greatest collection of autonomous instruments the Arctic Ocean has ever seen,” Perovich says. So scientists are hopeful that they will still have baseline information. And even the minimum will create a much larger data set than we’ve ever had during this time period in the central Arctic, Perovich says.

That assumes the instruments will remain intact. In reality, they will be vulnerable to changing Arctic conditions — from shifting ice that might crush equipment to curious polar bears. Both scenarios have already occurred during the mission.