June 15, 2020

Postcards from a frozen icebreaker — Part 30

Posted by larryohanlon

By Matthew Shupe

6/8/20 Three Ships
Anchors up, and underway. After a few days of turnover, we are now on our way. We’ve said goodbye to our Leg3 colleagues, after absorbing as much information as possible on their experiences, the state of the instrumentation, and ideas on how to proceed. Then a last farewell on the working deck as they walked the gangway over to the transfer ship. Some cheering. Some crying. Many hugs, and lots of waving as the ships finally parted.

They were guided out of the small side fjord off Longyearbyen out into the broader Isfjord. Fog and some scattered low clouds masking the mountains at times. But then a sun splash and a glimpse of broad valleys parting snow capped mountains. This land has so obviously been carved by glaciers. Out in the fjord the winds whip strongly. To stand on Polarstern’s deck was a challenge….but many of the science team braved the wind and snow to savor the moment. The transfer ships, Sonne and Maria S. Merian, sailing out ahead, side-by-side. Then Polarstern gaining speed and moving into position between the others. Three ships abreast, blazing their way through the fjord. Quite a scene. Truly exhilarating to be standing on the deck moving forward with such power.

After countless goodbyes, some tears, and final warm farewell words from Captain Wunderlich, the Polarstern headed back north and Maria S. Merian headed South. Photo: Christian R. Rohleder/Alfred Wegener Institute (CC-BY 4.0)

6/9/20 Re-entry
Déjà vu. At about 11:30 ship time today Markus and I stood on the P-deck above the bridge on Polarstern and looked out across the approaching sea ice edge. We did the same back in September as Polarstern embarked for the first time into the ice to start MOSAiC. Now it is to restart MOSAiC. Then, it was much windier. Now, it is actually quite mild.

The edge is so clearly demarked now. Unlike some of my voyages in the past, here there were no stray chunks of ice extending out to meet us. Instead, a mosaic of shapes and colors, most less than about 30 feet across, all jumbled close together. Polarstern approached and pushed through without problem. Right away we could see some very thick ice, remnants of pressure ridges. Here and there bright blue patches where melt ponds hand already started to form on the ice. But with the slightly colder temperatures in the last couple of days these ponds typically had a thin layer of ice on top. And all of the ice was bright white, blanketed in a thin layer of new snow.

This state is clearly transitionary. The ice is flirting with the melt season. It has warmed dramatically in the last couple of weeks and started to melt from the top…. But then cold air flowing in from the north has put a temporary stop to that melt, even turning it around a bit. The new snow means that relatively more of the incoming sunlight is reflected back to space…. Providing somewhat of a buffer for the ice. I guess this will be for only a short period as we are getting well into June now and the overall solar input is large and growing. The temperatures outside are right at the melting point. And the clouds are a persistent blanket, further boosting the amount of heat that is trapped by the surface. Many here wait in great anticipation for melt to reveal itself again, and to possibly take hold of the ice consistently for the coming season.

A Minke whale makes an appearance as Polarstern heads back to the floe. Photo: Lisa Grosfeld/Alfred Wegener Institute (CC-BY 4.0)