MOSAiC Expedition Reaches the North Pole

Published: 20 August 2020

During the final leg of the expedition, the research vessel Polarstern reaches the northernmost point on the Earth

Polarstern heads to the new MOSAiC ice floe via the North Pole — Heading for the new MOSAiC ice floe, the *Polarstern* takes the shortest way to the area of interest: via the North Pole. On the way north, the sea ice is surprisingly weak and has lots of melt ponds, and the *Polarstern* is able to easily break it. Photo is by Steffen Graupner, Alfred Wegener Institute.

At 12:45 p.m. on August 19, 2020, the German research icebreaker Polarstern reached the North Pole. The ship followed a route to the north of Greenland—and through a region that, in the past, was densely covered with ice, including multiyear ice. The journey from the northern Fram Strait to the pole only took six days to complete. To mark this momentous event, countless members of the expedition team gathered on the bridge, where their eyes were glued to the position monitors, and then celebrated having reached the pole together.

This year satellite imagery indicated that, even past 87° North, the ice cover was surprisingly loose. Accordingly, MOSAiC Expedition Leader Prof. Markus Rex and Polarstern Captain Thomas Wunderlich decided to head north, starting from the position of the last resupply rendezvous in the northern Fram Strait between Greenland and Svalbard. “Up until 87° 30’ North, for the most part we passed through open water, in some cases stretching to the horizon,” recalls Prof. Markus Rex from the Alfred Wegener Institute (AWI), Helmholtz Centre for Polar and Marine Research.

“Based on the satellite imagery, at first we weren’t sure whether the loose ice cover was due to wind and currents, and were concerned that, if it was, a change in weather conditions could compact it again. Then we would have been caught in a mousetrap, and could have become trapped in the ice,” reports the MOSAiC expedition leader, who had previously reached the North Pole onboard a research aircraft, in 2000.

The MOSAiC chief scientist and Polarstern captain hold a commemorative plaque for the North Pole visit — Markus Rex, MOSAiC chief scientist, and *Polarstern* Captain Thomas Wunderlich hold a steel plaque that was especially made for the visit to the North Pole. Photo is by Lianna Nixon, University of Colorado, Boulder.

Once in the region, however, they found that much of the sea ice truly had melted away and hadn’t simply been broken up by the wind. This is yet another unique phenomenon that was observed and investigated during MOSAiC, following the substantially accelerated melting rates in the Siberian sector in July.

For the final phase of MOSAiC, the expedition team is focusing on the freezing phase: the last piece of the puzzle in terms of observing the arctic ice throughout its annual cycle. After the MOSAiC floe, as expected, broke up near the ice edge in Fram Strait in July, the team set course farther north, where the freezing phase will soon begin.

For more information, read the full AWI news release. To see MOSAiC photos, view AWI’s multimedia page.

On the Polarstern, instruments from the Atmospheric Radiation Measurement (ARM) user facility continue to collect data for the expedition, which is scheduled to end in October 2020.