The Polarstern in Antarctica in 2013, on a previous expedition. The ship becomes frozen in sea ice, allowing an interdisciplinary research program on atmosphere, sea ice, ocean, and ecosystem as the sea ice grows and then melts.Alfred-Wegener-Institut/Stefan Hendricks
When the German icebreaker Polarstern leaves Norway’s coast on Sept. 20, it will embark on a year-long drift across the Arctic Ocean. Two University of Washington researchers are among scientists from 17 nations who will study climate change from a unique floating research platform.
The Arctic has warmed dramatically over recent decades, but observations are scarce during the ice-covered winter. The MOSAiC expedition, or Multidisciplinary drifting Observatory for the Study of Arctic Climate, will enclose the research icebreaker Polarstern in sea ice for a year, creating a drifting research platform that will pass near the North Pole.
Two UW researchers – Bonnie Light, a principal physicist at the UW’s Applied Physics Laboratory and an affiliate associate professor of atmospheric sciences, and Madison Smith, a recent UW graduate who is now doing her postdoctoral research at the UW – will join for the fifth of the six two-month legs, in summer 2020.
“This project is a once-in-a-generation endeavor,” said Light, a member of the UW Polar Science Center. “It takes a tremendous amount of commitment, resources and planning to pull off a campaign of this scope.”
The UW scientists will leave from Norway in June aboard the Swedish icebreaker Oden, then travel for about two weeks to the research base, which at that point is projected to be between 85 degrees and 90 degrees north latitude, to the north or northeast of Greenland. They will then make a final leg to reach the ship.
The massive international collaboration, years in the planning, begins this week in Tromsø. The main research vessel will remain in visual contact with an escort icebreaker through September as the two ships head across the Barents and Kara seas on course for the Central Arctic. After roughly two weeks they are expected to reach the target region at 130 degrees east longitude and 85 degrees north latitude. The first of six teams will then search for a suitable ice floe to set up the complex research camp. They will be working against the clock, since just a few days after their arrival the sun will cease to rise above the horizon. Expedition participants will connect the base camp to a network of measuring stations set up over a radius of about 30 miles (50 kilometers). The escort ship, a Russian icebreaker, will then leave.
The first group of people living aboard the Polarstern will remain there until mid-December, when they will be replaced by the second team. In late summer 2020, between Greenland and Svalbard, the Polarstern will free itself from the sea ice and head back to its homeport of Bremerhaven, Germany, where it is expected to arrive in mid-October 2020.
Following the sea ice for a full year offers unique opportunities, said Light, who studies “rotting” or melting ice. She and Smith will be part of the sea ice team and will focus on how sunlight is reflected, transmitted and absorbed by the ice cover as it melts.
“If you just show up in summer to study the summer melt, you have to do a lot of guessing about how the ice got to that point,” Light said. “I’m particularly interested in the melt ponds that we expect to form on the ice surface, which affect how sunlight is reflected to the atmosphere and transmitted to the ocean.”
Light said she feels especially lucky to participate because as a UW doctoral student she participated in 1997-98 in ice station SHEBA, a UW-led project that also involved a full year of continuous Arctic observations.
“The nature and character of the Arctic ice cover has changed tremendously in the 21 years,” Light said. Multiyear ice is shifting to thinner, seasonal sea ice, she said.
“We didn’t used to talk much about sunlight penetrating beneath the ice cover, but the ice is thinner than it was 20 years ago,” Light said. “We think sunlight is now a significant factor in the heat content of the central Arctic Ocean.”
More about the MOSAiC Expedition