Expedition in Arctic winter – a good idea?

In Arctic winter 2020, AGENSI researchers went on an expedition with research vessel Kronprins Haakon to the sea ice covered East Greenland Sea. This is what happened.

Anticipation

Finally! After working with different aspects of sea ice reconstructions for several years, I was going to see sea ice for the first time from up close. In fact very up close, in one of the most remote regions in the Northern Hemisphere during complete winter darkness. The weeks before the expedition, the AGENSI team prepared eagerly and impatiently awaited the departure date of our Arctic expedition together with researchers from CAGE at University of Tromsø. With the threat of Covid-19 and quarantine periods around, we were all a bit anxious that the expedition would be cancelled last minute. But we were lucky. The cruise went ahead as planned, and we left Bergen on 14 November for an expedition in the true sense of the word.

An expedition with the fantastic RV Kronprins Haakon to the East Greenland Sea in the midst of Arctic winter, with no guarantee of success but a great chance of funky weather and waves. Exciting!

First encounter with sea ice

The expedition started on 17 November with an equipment test in Isfjorden near Svalbard. Everything went smooth, and we immediately set off towards East Greenland in what was announced to be a “liten kuling”. This Norwegian expression sounds harmless, but means gale and 6–8 on the Beaufort Scale. In practice, this turned out to be waves up to 7 meters. And so eating lunch became a challenge, especially when you feel like you are playing musical chairs on a rollercoaster. After being “thrown” around for 24h, we woke up the next morning to the sound of things bumping into the boat, in the calmest of waters. At Hovgård Ridge, we had reached the sea ice. Little sea ice at first, with large open stretches of water, soon turned into a white flat landscape with sea ice cover stretching to the horizon.

Our daily and nightly work

With every hour spent in the cold, the boat slowly started to ice over in temperatures down to -18 ˚C. We were now really on our way to the Greenland Shelf. There we were hoping to observe gas flares on the sea bottom; the main goal of the cruise for our CAGE colleagues. On the way there, the plan was to collect samples for the AGENSI project. We had our first scientific station in the middle of the sea ice, where the ocean was ca. 1500 m deep. As everything was pitch dark outside, you could not tell if it was day or night.

We deployed equipment for water sampling, for collecting undisturbed sea floor sediments and long sediment cores to investigate the climate and ocean conditions from long past times. This routine continued throughout the expedition, and we ended up with water and sediment samples from 11 different locations or, in cruise terms, stations. At one station, we even collected ice cores and saw some twilight at the horizon. The first glimpse of sunlight above sea ice covered ocean after several days in the dark.

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Different shapes of sea ice

Sea ice has all kinds of forms: grey, thin, freshly formed sea ice covered with ice flowers; thick, blue ice covered with snow as far as the eye could see; sea ice ridges up to 2-3 m high; but also leads and patches of open water, as dark as the darkest Arctic night. This remote region (Greenland was 300 km away, Longyearbyen even 450 km) was a quiet, almost alien world in black and white. As it is so remote, you don’t expect to see any life. Yet the sea ice was full of microscopic life, and a large polar bear lazily walked by the boat one day.

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Bad weather approaching

It turned out that this time, the sea ice was too thick to get to our preferred study area. Even after countless attempts by the captain to break the sea ice, we had to make new plans. So flexibility became a key word, and together, the researchers on board brought out plan B and C, and went to investigate other interesting locations. Unfortunately, halfway through the expedition, a storm was building up in the south and we had to leave the sea ice, as there was a chance that we would get stuck. That sounds adventurous, but unplanned, this is not a good idea. We swiftly moved out of the ice, and collected seismic data as well as several sediment cores in more open waters, that will likely freeze over in the coming weeks and months.

The storm kept nearing on us, and we also had to leave that area to steam back to northern Norway on wavy seas. The weather was trying to catch up with us… but before returning to Tromsø, we had one final stop in the relative calm of a Finnmark fjord. Early in the day, against the backdrop of pink skies over snow covered mountains, we collected our last samples. The area is believed to hold information on the history of the Scandinavian and Barents Sea ice sheet. The sediments we collected there will hopefully reveal that in the coming months, when we start working on analysing every detail in the lab.

Science back at home

That is what we are all looking forward to now: weeks of analysing our samples for microfossils, geochemistry, and its genetic (DNA) contents in a warm and comfy labs. Together, this will tell us about the climate history of the regions we visited. Specifically for AGENSI, new tools to investigate past sea ice cover and the sea ice history of the last few ten thousand years will receive most attention. So we may not have reached the expected target region of the cruise, but we have nevertheless collected a lot of excellent material for our research.

Expeditions in Arctic winter? Challenging, but with flexibility and great team work, these can be made into a success!

With thanks to Jochen Knies, Monica Winsborrow and the rest of the CAGE research team, the RV Kronprins Haakon captain and crew, this became the second successful AGENSI cruise.

An account of the expedition and her PhD research by Danielle Grant can be found here. A cruise blog by Mauro Pau was published on the CAGE cruise webpages here.