Multiyear Ice in the Arctic Has Practically Vanished
06.11.2009 - Water & Oceans, Ice & Snow, Other, Arctic
The vast expanses of multiyear ice that once covered the Arctic Oceanand were a major hindrance in navigating through the Arctic forcenturies has practically vanished according to Canada's Research Chairin Arctic System Science at the University of Manaitoba, David Barber.Barber recently returned from an expedition to find multiyear sea icein the Arctic only to find very little.
According to Barber, the littlemultiyear sea ice that remains is jammed up against the coast ofCanada's Arctic Archipelago, far from potential shipping routes. "From a practical point of view, the Arctic is almost seasonally ice-free now", says Barber. Since multiyear sea ice is the main barrier to the use and development of the Arctic, shipping companies are already looking to benefit from warming waters, with two German cargo ships successfully navigating from South Korea along Russia's northern Siberia coast without the help of icebreakers this year.
Scientists believe that elevated greenhouse gasses are the cause for the higher temperatures in the Arctic and the retreat of sea ice. Scientists have been worrying about the pace of melting ice for years, and the 2009 sea ice cover was the third-lowest extend on record. An increasing number of experts now feel the North Pole will be ice free in summer by 2030 at the latest, for the first time in a million years.
Being highly reflective, as sea ice retreats, the overall albedo of the Arctic drops as heat absorbing darker surface of sea water are exposed to the sun. The ice is now being melted both ways, from the sun's rays from above and from the sea water below, warming the Arctic up to three times faster than other parts of the world.
Scientists are also seeing more cyclones, which pick up force as they absorb heat from the warmer Arctic water. These cyclones then help generate waves that break up ice sheets, preventing them from thickening.
"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.
