They have been tracking the Arctic ice for decades

The height of the Swedish summer saw the start of the Arctic polar expedition SWERUS-C3. On board the icebreaker Oden were two seasoned Arctic researchers from the University of Gothenburg. In some ways this was a voyage they had made many times before, but in other ways it was extremely different.

“Well, now I’m on my thirteenth and last research expedition to this fantastic environment. However, the environment is different to what it was on my first expedition. I have seen clearly how the conditions of the ice have changed.”
Leif Anderson, 6 July 2014, Travelogue 1

Professor Leif Anderson

Professor Leif Anderson

In 1980, Leif Anderson, a Professor in Marine Chemistry, made his first polar expedition to the Arctic Ocean.   At that time there was plenty of ice that was many metres thick which had been built up over the course of several winters. It looks different today. The areas that had previously been covered in ice are now open sea.

“These days you’ll find the ice that is several years old mainly to the north of Greenland. This is a sign that climate change is happening,” Leif Anderson says. “We’ve passed the point of thinking that this would be something to worry about in the future – the reality has caught up with us now.”

The aim of the SWERUS-C3 expedition was to study the way the changes in ice conditions have affected the conversion of organic material into carbon dioxide and the transport of methane and carbon dioxide from the sediment to seawater and then the atmosphere.

It is not only the ice conditions that have changed during the years that have passed since Leif Anderson’s first expedition. Today there are laboratories, measuring equipment permanently in place and winches of different sizes for sample taking that did not exist 34 years ago. This means significantly improved working conditions on board and the right conditions for modern research. Communication with the outside world is also different.

“In the past, the only possible way to make contact with the outside world was to communicate via long wave radio.” Now we can call home via satellite telephone and send and receive emails.

“A large part of SWERUS’ objective is to map the methane gas deposits and flow from the bottom sediment. The area we’re starting at is familiar to us from past visits, and we know that large amounts of methane bubble up here from the seabed.”
Göran Björk, 10 July 2014, Travelogue 2

Professor Göran Björck

Professor Göran Björck

Göran Björk is a Professor of Oceanography and has eight polar expeditions behind him. On the SWERUS-C3 expedition, he headed a group of four researchers who studied the way ocean circulation is governed by the bottom topography and the confluence between shelf sea and deep ocean. The changes in the Arctic landscape opened up completely new opportunities for them.

“The ice cap is giving way to sea over the Lomonosov Ridge and is forming a large open bay,” he says. “We were able to map the underwater ridge for the very first time, because that area had previously been covered in ice. Before that we hardly knew what the seabed looked like there.”

Göran Björk’s research is concerned with measuring salinity, temperature and chemical data to map the large-scale ocean circulation in the Arctic. He is especially interested in the confluence at the point where shelf meets deep ocean and in the way deep-sea ridges affect the circulation.

“There are interesting things now happening in chemistry. Oxygen concentration levels begin to fall near the seabed, a clear signal that organic material is being broken down. This also means that carbon dioxide concentration levels are rising.” Leif Anderson, 28 July 2014

During the summer when phytoplankton flourish, the sea usually undersaturated in carbon dioxide. Research shows that the reason that the sea is now becoming saturated in carbon dioxide is presumably the input of organic material from land that had previously been trapped by the permafrost. When the permafrost thaws, the material is carried into floodwaters and the sea, where it is broken down by micro-organisms and reinforces the greenhouse effect.

“We observed this during an expedition to the same sea in 2008, but that was in areas closer to land than where we’ve been this time,” Leif Anderson says. “Coastal erosion has consequences for people living in those areas, but the increasing leakage of carbon dioxide affects us too since it’s connected to the global climate system.”

Leif Anderson has carried out his last polar expedition. Göran Björk is less certain on this point.

“The last few times I’ve said ‘never again’ after every expedition, but we’ll have to see,” he says with a brief smile.

SWERUS-C3

Expedition on the icebreaker Oden, from Tromsö via the Arctic Ocean to Alaska and back during July-October 2014. 74 researchers took part. The objectives were to study the links between climate, cryosphere (frozen areas such as ice, snow and permafrost), the conversion of carbon and the flow of greenhouse gases into the atmosphere.

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