Tuesday, October 10, 2006

Arctic Ocean losing more sea ice every year, warn scientists


DENVER, Col.: Continually decreasing sea ice in the Arctic Ocean prompted a group of researchers yesterday to warn that this Polar region may have no sea ice by 2060.Measurements taken by satellite indicated that the sea surface area covered by ice floes was at its minimum in 29 years, a result of global melting. A team of scientists from the National Snow and Ice Data Center (NSIDC) made the observation. Team leader and senior researcher at NSIDC, Mark Serreze believes the phenomenon is linked with the rapid rate of global warming. The researcher suggested it could also be the result of a self-perpetuating warming cycle.By covering much of the northernmost ocean, sea ice works like insulation preventing the sea water from warming up. The ice reflects much of the sunlight which would otherwise heat up the sea water. Seasonal temperature changes affect the extent of sea surface covered by these ice bodies. In summers, it is usually the lowest, with the ice floes melting down to their minimum around mid-September. The thermal expansion and runoff from melting icebergs and glaciers contribute to the rising sea levels. The decline in sea ice mass would be recovered during winters, under normal circumstances. However, the entire Arctic mass of sea ice has been on a long-term decline, reaching new lows every summer. The level observed on September 14 was the fourth-lowest recorded since 1977 when satellites were put in place to monitor the weather patterns in the region. Co–researcher Julienne Strove worried that "at this rate, the Arctic Ocean will have no ice in September by the year 2060".Lead researcher Dr Serreze said the Arctic region would be the first to be affected by global warming. He explained the self-perpetuating warming cycle as: the more sea surface there is the more sunlight and heat it will absorb, which in turn would result in more sea ice melting.

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