Blog Archive

Friday, November 29, 2013

NPS researchers predict summer Arctic ice might disappear by 2016, 84 years ahead of schedule

by David Schmalz, Monterey County Weekly, November 27, 2013

Tucked away on the third floor of the Naval Postgraduate School’s building of Engineering and Applied Sciences, a small team of researchers is leading an effort that will change the way the world thinks about the world. Their project is the Regional Arctic System Model (RASM), and it is arguably the most advanced – and accurate – Arctic climate model in existence.
Model Climate
Lt. Dominic DiMaggio describes the area captured by NPS’s innovative Arctic climate model, a project involving 25 researchers and graduate students from 10 institutions.
On a recent, sunny winter day, U.S. Navy Lt. Dominic DiMaggio – a master’s student in physical oceanography and meteorology and a RASM team member – lays out the model’s virtues and complexities, casually throwing around terms like “parameterization” and “highly non-linear functions.”
Then, almost 60 dizzying minutes later, he just as casually points to a graph showing a RASM projection for melting Arctic sea ice, a phenomenon that occurs every summer but has been accelerated by climate change: By the summer of 2016, the Arctic Ocean could be ice-free, opening the door to vast reserves of fossil fuel, and eventually, freeing up a shipping lane between Europe and Asia.
NPS Professor Wieslaw Maslowski, who leads the team of researchers behind RASM, says 2016 is at “the lower bound” of the current range of projections, while DiMaggio calls it “an aggressive interpretation” of RASM. But most conventional climate models predict the Arctic won’t have a sea ice-free summer until 2100. So why is the RASM model so different?
Mainly, it’s a matter of scope. Because most climate models are projecting the global climate, there is not enough computing power to account for what can often be key regional details.
One example DiMaggio gives is the Bering Strait, a narrow strip of water that is too small (51 miles wide) to be accurately accounted for in the wider lens of global models, but which “is significant in its impacts to the central Arctic.”
The amount of detail that RASM is able to capture in the Arctic is at least 10 times greater than a global model, and not only calculates projections based on air, ocean and ice conditions (which are standard in global models), but also includes inputs for land and riverflow.
“We’re modeling river runoff, the permafrost, the glaciers, even the chemical and biological processes,” says DiMaggio. “The ocean isn’t just the water, it’s the entire environment. And that’s what we’re trying to capture.”
RASM’s findings will help inform the Navy’s understanding of a region that is home to over a thousand miles of U.S. coastline, and which is changing faster than many expected, a reality charged with geopolitical implications. The Navy predicts the potential for extracting fossil fuels and minerals, as well as significantly shorter shipping routes, will likely attract commercial interests.
The stark image of an ice-free Arctic, meanwhile, might also impact the climate change discussion, one that Maslowski hopes “will be a critical argument against skeptics of global warming.”
RASM has the potential to greatly alter current global climate models.

“We’re hoping global modeling groups will use what we’ve learned to improve their models,” Dimaggio says, “so the decision makers have a better understanding of what’s actually happening.”

No comments: