NASA: Arctic Sea's icecap is melting

Thursday, September 14, 2006 

Arctic Sea ice minimum in 1979.

NASA scientists say that the Arctic Sea's icecap is melting and that the icecap is melting fast.

According to images captured by NASA's QuikSCAT satellite, the Arctic icecap has lost at least 14% of its 'perennial' ice between 2004 and 2005. Data shows that at least 280,000 square miles of ice, at least the size of Texas has been lost. The eastern Arctic has lost at least 50% of its ice, but scientists say that ice was shifted by wind and other weather factors from the east to the west Arctic, causing the western areas of ice to actually grow.

Between October 2005 and April of 2006; however, the icecap lost an additional 70% of frozen water.

Between 04 and 05, the perennial ice, which is supposed to remain frozen year-round, was replaced by 'seasonal' ice, which scientists say melts faster during the Summer months. This event has never before been witnessed. Perennial ice is normally 3 meters (10 feet) thick or more and seasonal ice is only 0.3 meters (1 feet) to 2 meters (7 feet) thick.

Arctic Sea ice minumum in 2005.

"If the seasonal ice in the east Arctic Ocean were to be removed by summer melt, a vast ice-free area would open up. Such an ice-free area would have profound impacts on the environment, as well as on marine transportation and commerce," said Son Nghiem, the leader of research at the Jet Propulsion Laboratory in Pasadena, California.

For several decades, the icecap has melted about 0.7% a year during the Summer months and has increased at least "18 times" faster than past decades, but Nghiem also said that the icecap has melted with "some variability" over the past years and was at times a "much smaller" of a loss of ice.

"If we average that over the long term we find a reduction of between 6.4% and 7.8% per decade. What we have here is 14% in one year - 18 times the previous rate. In previous years there is some variability, but it is much smaller and regional. [The changes between] 2004 and 2005 is enormous," added Nghiem.

Global warming is believed to have played a role in melting the ice.

"It has never occurred before in the past. It is alarming. ... This winter ice provides the kind of evidence that it is indeed associated with the greenhouse effect," said Josefino Comiso, another NASA researcher and scientist.

Sources

• Seth Borenstein. "Arctic ice melt alarms climate researchers" — Detroit Free Press, September 14, 2006

• Richard Black. "'Drastic' shrinkage in Arctic ice" — BBC News, September 14, 2006

• Aalok Mehta. "Arctic Ice Melting Rapidly, Study Shows" — National Geographic, September 14, 2006