Tuesday, March 23, 2010

Climate change not the biggest factor responsible for Arctic ice melting?

Arctic sea ice has been shrinking rapidly in the last few decades, and this has lead to popular belief among many climate change scientists that Arctic region has already passed a climate tipping point, meaning that even bigger loss of sea ice is expected in years to come, and that very soon Arctic ocean could be ice-free during the summer months.

The latest study by Masayo Ogi, a scientist with the Japan Agency for Marine-Earth Science and Technology in Yokohama, and her colleagues does not question that climate change also played important role in Arctic sea ice loss but that there is one factor that could be even more important in explaining loss of Arctic sea ice. That factor are Arctic winds.

Ogi and her colleagues found that changes in Arctic wind patterns, such as summertime winds that blow clockwise around the Beaufort Sea, seemed to coincide with years where sea ice loss was highest, and that the ice blown out of the region by Arctic winds can explain around one-third of the Arctic sea ice loss trend in the last 30 years.

Arctic winds could be one of the major factors responsible for the loss of Arctic sea ice in the last 30 years.

The power of these winds has increased recently, and this could explain the current trend of decline in the areal coverage of Arctic summer sea ice.

In the last 30 years, the Arctic ice has shrunk by about 10% a decade, which is around 28,000 square miles each year. The ice reaches its minimum coverage each September, when it begins to expand as the freezing Arctic winter takes hold.

According to this study both winter and summer winds could have been responsible for blowing ice out of the Arctic in the last 30 years. Other factors were also responsible for loss of Arctic sea ice, like increased temperatures of air and ocean.

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