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.