As seen from space, the Arctic ice cap looks and acts like a giant amoeba splayed across the top of the world. It heaves and twists, reaches outward, then shrinks back.
“It’s constantly in motion,” says David Barber, while a time-lapse sequence of polar satellite images plays across his computer screen.
The more scientists study the sea ice that floats atop the Arctic Ocean, the more it resembles something that lives and breathes, a dynamic membrane that hosts microbial communities, fosters chemical reactions and connects air with water in surprising ways.
“It’s not just a cap, it’s an active participant in the system,” says Dr. Barber, who is director of the University of Manitoba’s Centre for Earth Observation Science. “That has global implications.”
Those implications matter to marine life, planetary weather patterns, human health and northern development – more than enough reason for the Arctic sea ice to warrant scientific attention. It has also motivated a major expansion at the centre, backed by a $10-million Canada Excellence Research Chair and $48-million in additional funding. The centre now has more than 100 scientists, graduate students and technicians, making it the world’s largest research group focused on sea ice.
But even as the centre celebrates the opening of $15-million, state-of-the-art laboratory facilities next week – including custom freezers, where sea ice can be grown under carefully controlled conditions, and a remote-controlled submersible that can explore and sample the environment under the ice – a sense of urgency about the Arctic pervades the effort.
“It’s the part of the planet which is realizing the first and the fastest response to climate change,” says Tim Papakyriakou, one of the centre’s scientists who specializes in carbon transfer between ocean and atmosphere. “This system that we had a poor understanding of before is now changing very, very fast.”
While ice over the Arctic Ocean always grows in winter and retreats during the summer, its minimum extent, typically measured in September, is on a downward trend. Last year it hit a record low, dipping to 3.41 million square kilometres. It now looks like the Arctic will become ice free during the summer some time between 2015 and 2030.
Climate models predict a decline in sea ice as the planet warms, but nowhere near this fast. Understanding why the ice is vanishing so quickly is at the top of Dr. Barber’s agenda. Part of the answer, he says, has to do with the simple fact that water is darker than ice and absorbs more sunlight than it reflects. The more open ocean there is in the Arctic, the more solar energy is deposited there during the summer. At the onset of winter, this extra energy must be dissipated as heat before new ice can form, a process that can last well into December.
But Dr. Barber also sees a similar pattern in January and February. There is still more open ocean during those months than there was in the past, even though the High Arctic is in winter darkness during those months and excess solar energy should not be a factor.
Dr. Barber believes he has identified another influence contributing to the disappearance of the sea ice: Atlantic water entering the Arctic system via the Gulf Stream. It’s warmer and more buoyant than it used to be, which means it’s welling up under the sea ice and melting it from below.
“We’re losing more ice than we thought we were, but it’s an ocean heat source,” he says.
But converting such a sweeping change into an accurate prediction for the future also requires an intimate understanding of the sea ice at small scales. Ice that forms in different conditions of temperature and salinity, with more or less air content, will respond differently to environmental change. Biology also plays a role, as microbes colonize the ice, secreting chemicals such as sugars and also changing the amount of solar energy the ice absorbs.
“All of these things have to be taken into account,” says Nadja Steiner, a research scientist with the Department of Fisheries and Oceans, based in Sidney, B.C.
Dr. Steiner, who specializes in modelling sea ice, says the kind of field and laboratory work conducted at the University of Manitoba is essential for validating large-scale models of sea ice and its effect on global climate.
“We want to be certain that the assumptions that are going into our equations are correct,” she says.
The loss of sea ice could already be having a significant effect on weather patterns across North America and Eurasia. It means the Arctic is warming faster than the mid-northern latitudes. This in turn alters the jet stream that flows over those regions, giving it a more wavy shape and creating “blocking events” that cause air masses to linger where they are, increasing the likelihood of both drought and flood, depending on the air masses and where they happen to get stuck.
It is precisely such a blocking pattern that seemed to cause Hurricane Sandy to veer toward the U.S. coast last October rather than take a more typical and more benign course across the North Atlantic. “We’ve lost so much ice that it’s really hard to imagine it not having an effect on the global climate system,” says Jennifer Francis, an atmospheric scientist at Rutgers University who has helped to uncover the link between sea ice and the blocking phenomenon.
Reproducing Arctic conditions in Winnipeg
One of the new tools at the University of Manitoba that ice researchers are most keen on is an outdoor, swimming-pool-sized, saltwater tank that can be used in the depths of the Winnipeg winter to simulate the growth and behaviour of sea ice. For researchers, the Sea-ice Environmental Research Facility bridges a gap between the small-scale but tightly controlled experiments that are done in the lab and observations made in the field, where innumerable variables are at play.
“It really provides that missing link,” says Feiyue Wang, an environmental chemist who oversees the facility. “We know there are certain phenomena we can reproduce at this intermediate scale.”
Among those phenomena are “frost flowers” – beautiful and delicate crystal formations that blossom on sea ice when conditions are just right. Unpredictable and hard to study in the field, frost flowers are central to Dr. Wang’s research on mercury contamination in the Arctic. He is looking at how the blade-like leaves of the flowers can act as conduits that draw mercury out of the air and convey it into the marine ecosystem. The work relates directly to the health outcomes of northern people who are exposed to mercury through traditional food sources.
Dr. Wang has managed to coax frost flowers into bloom at SERF, which is allowing him not only to understand how they channel mercury but, importantly, whether that process will increase as thick “multi-year” sea ice that re-freezes every winter is increasingly replaced with thinner, more permeable ice that forms over one season, thereby speeding up interactions between ocean and air.
“Sea ice is different from the ice cubes you put in your drink,” says Soren Rysgaard, the Canada Excellence Research Chair who joined the centre in 2011. The difference lies in the salt and mineral content of the water that become concentrated as the water freezes. “It makes all these channels and tunnels in the ice,” he adds. “When you concentrate all these chemicals, they can form other components.”
Dr. Rysgaard’s work includes the discovery that calcium carbonate crystals known as ikaite form in abundance in the tiny channels that thread their way through the sea ice. A by-product of this process is carbon dioxide, which in turn is carried by the briny runoff down into the ocean depths.
“The sea ice suddenly starts acting as a pump,” Dr. Rysgaard says.
Where all that carbon dioxide goes and what happens to the pump as the sea ice starts to diminish is part of a vast and complex chemical loop that Dr. Rysgaard is trying to decipher. To help illuminate this bigger picture, he is preparing for a campaign in 2015 that will send international teams fanning out across the Arctic to make similar measurements at the same time, capturing an unprecedented snapshot of the entire sea-ice system in action.
Although he is often working in the Arctic and divides his time between Denmark, Greenland and Winnipeg, Dr. Rysgaard adds that the newly built research facility at the University of Manitoba will be an essential platform for tracing the hidden chemistry in the sea ice and its relevance to the global climate system.
“We have people coming from all over the world to do experiments,” he says. “You can do a lot of things here that cannot be done in the field ... or in very many places.”
‘Something really serious is going on in the Arctic’
Thinning ice produces melt ponds that sit atop the ice and effectively become windows, allowing light to penetrate into the sea below. Last year researchers began reporting vast blooms of algae erupting under the ice, where they can rapidly exhaust the nutrients in the water’s upper layers.
Such phenomena are the province of Marcel Babin, a Canada Excellence Research Chair who specializes in remote sensing of the Arctic at Laval University and who collaborates with the University of Manitoba group.
Dr. Babin relied on satellite imagery to estimate the concentration of plankton in the ocean based on colour changes in the water and used this to calculate the ocean’s biological productivity. Of key importance is the so-called spring bloom, an eruption of algae along the edge of the sea ice that occurs when sunlight begins returning to the region every spring. The bloom, which feeds off nutrients that have accumulated over the winter, accounts for much of the productivity of the Arctic Ocean.
Now Dr. Babin and his colleagues are watching to see if the bloom moves northward as the sea ice retreats. The question is whether the algae will keep blooming all the way to the North Pole as each spring brings thinner, more transparent ice – or whether it will be stopped short by limitations in the environment.
“That’s important because it will tell us about the potential for the Arctic Ocean to become more or less productive,” Dr. Babin says.
A more immediate change that Dr. Barber and his colleagues have observed is the increase in the speed of pieces of ice moving in the southern Beaufort Sea. This is simply because, with more open water, large blocks of multi-year sea ice have less in their way, allowing them to drift at higher speeds and then pile up with more force when they finally collide with something. They carry too much momentum for ice breakers to handle, so they pose a new threat to drilling operations that are increasingly expected to move into northern waters.
The finding came about as a result of work that the centre has been doing for oil and gas exploration companies, which Dr. Barber sees as an important part of the centre’s mandate.
“Overall the relationship works well so long as the university stays at arm’s length,” he says. “We want them to have the best information they can possibly have.”
For Dr. Barber, it is clear that the rapid changes under way in the North carry vast implications for resource development. It is the role of scientists, he says, to help ensure that the development is done in a sustainable manner that places a high priority on the ecosystems and peoples of the Arctic.
The interconnections between science, environment, industry and culture are evident in the naming of the new research facility after Nellie Cournoyea, a former premier of the Northwest Territories and now CEO of the Inuvialuit Regional Corporation, which seeks the meaningful participation of the western Inuit in the development of northern resources.
Dr. Barber speaks of the strong ties that have developed between scientists at the centre and the people who call the Arctic home. But he is also looking to a larger community, encompassing the rest of the globe, that is connected to the sea ice in a myriad of subtle ways that he and his colleagues now hope to uncover.
“I’m very much convinced that something really serious is going on in the Arctic,” Dr. Barber says. “We need to inform the planet about what it is.”Report Typo/Error