October 30, 2009

Arctic Multiyear Ice Practically Vanishing

Polar shipping routes have finally been unblocked, thanks to the virtual disappearance of the multiyear ice spanning the Arctic Ocean, according to an Arctic expert.

For centuries, enormous sheets of multiyear ice reaching up to 260 feet thick have impeded the way of ships looking for a short cut through the fabled Northwest Passage from the Atlantic to the Pacific.

However, Canada's Research Chair in Arctic System Science at the University of Manitoba, David Barber, noted that the ice is vanishing at an unbelievably fast rate.

In a presentation to Parliament, Barber said, "We are almost out of multiyear sea ice in the northern hemisphere."

The small amount of multiyear ice can be found shoved up against Canada's Arctic archipelago, quite a distance from any possible future shipping routes.

Scientists have found a connection between higher Arctic temperatures and melting sea ice to the greenhouse gas emissions that are held responsible for global warming.

Barber gave the presentation soon after he came back from an expedition that tried, and pretty much failed, to find a giant multiyear ice pack that was supposed to be in the Beaufort Sea off the Canadian coastal town of Tuktoyaktuk.

He only succeeded in finding hundreds of miles of what he referred to as "rotten ice", which consists of 20-inch thin layers of fresh ice over small chunks of older ice.

"I've never seen anything like this in my 30 years of working in the high Arctic...it was very dramatic," he said.

"From a practical perspective, if you want to ship across the pole, you're concerned about multiyear sea ice. You're not concerned about this rotten stuff we were doing 13 knots through. It's easy to navigate through."

For decades, scientists have been greatly concerned about the rate at which the Arctic ice sheets are shrinking, and U.S. data shows that the 2009 ice cover was the third-lowest on record, after 2007 and 2008.

More and more experts believe that, for the first time in a million years, the North Pole will be void of ice during summers by 2030 at the latest.

"I would argue that, from a practical perspective, we almost have a seasonally ice-free Arctic now, because multiyear sea ice is the barrier to the use and development of the Arctic," said Barber.

Every winder there is new first-year ice forming, when the North Pole is not exposed to the sun, causing temperatures to drop well below freezing.

There have already been shipping companies to benefit from the warmer waters. This year, two German cargo ships made their way from South Korea along Russia's northern Siberia coast without the use of icebreakers.

The Arctic is warming up three times faster than the rest of the Earth, partly due to the reflectivity, or the albedo feedback effect, of ice.

As an increasing amount of ice disappears, there will be greater levels of sea water exposed. The sea absorbs more sunlight than the ice and in turn makes the water hotter even faster, thereby melting more ice.

According to Barber, the ice is currently being melted both by rays from the sun as well as from below by the warmer water.

Scientists have also been seeing more cyclones, which become stronger as they pick up heat from the warmer water. The cyclones also help produce waves that break up ice sheets and also dump large amounts of snow, which provides a form of insulation and keeps the ice sheets from thickening.

Barber's ice breaker finally found a 10-mile wide floating sheet of multiyear ice that was around 20-26 feet thick. Unfortunately, the crew saw a series of waves break and dissolve the ice right before their eyes within five minutes.

"The Arctic is an early indicator of what we can expect at the global scale as we move through the next few decades ... So we should be paying attention to this very carefully," Barber said.


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