More than a hundred years ago, Norwegian explorer Roald Amundsen won the race to be the first to reach the South Pole. “The main difference between Antarctic research today and a hundred years ago is that the expeditions no longer involve risking one’s life. In the past explorers could die out there in the field”, says polar researcher Anna Wåhlin.
That’s what happened in the winter of 1912 during the Terra Nova expedition. English Captain Robert Scott, who had already participated in a number of Antarctic expeditions and was predicted to be the first to reach the South Pole, died after great difficulties on 30 March. His rival, Roald Amundsen, returned to Norway as the first to reach the southernmost point on Earth.
“A hundred years ago Antarctica was really an unexplored region on the map. Now we know much more about the conditions there”, says Anna Wåhlin, professor of oceanography.
Together with research colleague Sebastiaan Swart, we talk about how technology in polar research has evolved over the years.
“There has been almost exponential growth in how we researchers collect data and the quality of that data. Today we can measure much more than we could just a couple of decades ago”, says Sebastiaan.
When a research ship left Cape Town headed towards Antarctica 10 years ago, only about 30 ocean samples were collected along the way, and at great cost.
“The exponential growth we have achieved through automation and use of underwater robots yields not only tens of thousands more measurements in the area, but it also gives us continuous measurements throughout the year”, Sebastiaan continues. “Previously, we were limited to the summer and had no idea what was happening in the other seasons, especially in winter. What has happened in the last five years is a revolution in maritime observations.”
One of the explanations for this progress is underwater vehicle – that is, unmanned robots that chart the ocean beneath the surface. Via satellites, the vehicles send information such as water flow velocity, temperature and salt and carbon dioxide content.
An important goal with data from underwater vehicles is understanding the interactions that exist between the Antarctic Ocean and the Earth’s climate and how they affect each other. The insufficient knowledge in these matters is one of the biggest uncertainties in current climate projections.
“We must not forget the international Argo network, with more than 3,000 buoys floating in the ocean and continuously taking measurements and collecting data”, Anna Wåhlin says. “The difference is large compared to the infancy of polar research, when a researcher lowered a bottle into ocean water, fished it up, measured the temperature with a thermometer and recorded the results on a slip of paper.”
With underwater robots, it’s possible to get below the glaciers. This summer the University of Gothenburg is getting its first large autonomous underwater vehicle (AUV) at just over seven metres long. But the smaller versions of underwater robots, ocean gliders, have already been tested. During an expedition to Antarctica last winter, researchers used a fleet of five such gliders.
“The Antarctic continent doubles in size during the winter season. We plan to send gliders under the ocean ice this year, or by next year at the latest, and for the first time we’re hoping to get measurements under ice in wintertime in the Antarctic Ocean”, Sebastiaan says.
With the help of the five gliders that were used during the winter expedition, researchers discovered new processes in the ocean that they didn’t know about before and that could not have been detected without the new technology. For example, they learned that the phytoplankton in the ocean absorb more carbon dioxide than previously thought.
“We saw that the plankton grew for one to two months longer than we had thought”, says Sebastiaan.
The researchers found that there are lots of small vortices in the Antarctic Ocean, approximately 10 kilometres in width. This is an important discovery because currents and ocean vortices change the physics of the ocean and affect how much heat the ocean can absorb.
“The deep sea functions as heat storage for the globe. If that heat were released, the Earth would become uninhabitable. Viewed from that perspective, the ocean is very important in reducing heat”, says Sebastiaan.
What polar researchers in the past and today have in common is that things don’t always turn out as planned.
Researcher Thomas Dahlgren, recently en route to the Antarctic with a British research expedition to study small animals under glacier ice, had to turn back because they encountered too much pack ice on the way.
“But even if we didn’t get all the way, I obtained good samples of the animals that live on the bottom of the Weddell Sea, a sea that borders the Antarctic Ocean”, Thomas Dahlgren said on a crackly phone line from Port Stanley.
Little is known about the shallow part of the Weddell Sea due to the extent of the large mass of ice.
“We got truly unique samples of animal life from the bottoms there, including many completely unknown species.”
Thomas and research colleague Adrian Glover now have 300 containers with samples of millimetre-size animals. All of them have been photographed while still alive. And with new DNA technology, scientists can obtain information such as how big the populations have been historically and how different areas have been isolated from each other. Such data can be used to understand the extent of ice in the past.
“Identification of animal life is as important as surveying ocean bottoms or mineral deposits. Knowledge about animals and about their DNA can be used in many ways, such as to study the effects of climate change. Through knowledge of animal life, we can also find out what the environment looked like around Antarctica in historic times and gain new knowledge about how serious today’s climate change is for ice in the Antarctic”, Thomas says.
What will be the repercussions when floating glaciers melt and disappear at an accelerating rate?
“It appears that warm water from the deep sea is what is melting the ice from below. I’m collaborating with Anna Waddell on this issue. We’re attacking the problem from two different directions, where I’m using animal life in an attempt to understand what’s happening with the climate”, Thomas says.