NASA Sees Rapid Changes in Arctic Sea Ice

September 13, 2006

NASA data shows that Arctic perennial sea ice, which normally survives the summer melt season and remains year-round, shrunk abruptly by 14 percent between 2004 and 2005. According to researchers, the loss of perennial ice in the East Arctic Ocean neared 50 percent during that time as some of the ice moved from the East Arctic to the West.

The overall decrease in winter Arctic perennial sea ice totals 280,000 square miles--an area the size of Texas. Perennial ice can be 10 or more feet thick. It was replaced by new, seasonal ice only about one to seven feet thick that is more vulnerable to summer melt.

The decrease in the perennial ice raises the possibility that Arctic sea ice will retreat to another record low extent this year. This follows a series of very low ice-cover years observed over the past four summers from active and passive microwave satellite data.

A team led by Son Nghiem of NASA's Jet Propulsion Laboratory, Pasadena, Calif., used NASA's QuikScat satellite to measure the extent and distribution of perennial and seasonal sea ice in the Arctic. While the total area of all the Arctic sea ice was stable in winter, the distribution of seasonal and perennial sea ice changed significantly.

"Recent changes in Arctic sea ice are rapid and dramatic," said Nghiem. "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."

The researchers are examining what caused the rapid decrease in the perennial sea ice. Data from the National Centers for Environmental Prediction, Boulder, Colo., suggest that winds pushed perennial ice from the East to the West Arctic Ocean (primarily located above North America) and significantly moved ice out of the Fram Strait, an area located between Greenland and Spitsbergen, Norway. This movement of ice out of the Arctic is a different mechanism for ice shrinkage than the melting of Arctic sea ice, but it produces the same results - a reduction in the amount of perennial Arctic sea ice.

Researchers indicate that if the sea ice cover continues to decline, the surrounding ocean will get warmer, further accelerating summer ice melts and impeding fall freeze-ups. This longer melt season will, in turn, further diminish the Arctic ice cover.

Nghiem cautioned the recent Arctic changes are not well understood and many questions remain. "It's vital that we continue to closely monitor this region, using both satellite and surface-based data," he said.

This is one of three study results being released today by NASA. The findings are the result of a new study by NASA; the U.S. Army Cold Region Research and Engineering Laboratory, Hanover, N.H.; and the National Ice Center, Washington, D.C. Study results are published in a recent issue of Geophysical Research Letters.

Source: NASA

Explore further: Cool summer of 2013 boosted Arctic sea ice

Related Stories

Cool summer of 2013 boosted Arctic sea ice

July 20, 2015

The volume of Arctic sea ice increased by a third after the summer of 2013 as the unusually cool air temperatures prevented the ice from melting, according to UCL and University of Leeds scientists. This suggests that the ...

Arctic nations bar commercial fishing around North Pole

July 16, 2015

Nations with territory in the Arctic on Thursday agreed to ban unregulated fishing in the rapidly melting international waters around the North Pole, amid fears they could be targeted by commercial operators in future.

Do micro-organisms explain features on comets?

July 6, 2015

Comet 67P/Churyumov–Gerasimenko, studied in detail by the European Space Agency Rosetta and Philae spacecraft since September 2014, is a body with distinct and unexpected features. Now two astronomers have a radical explanation ...

Recommended for you

Drought's lasting impact on forests

July 30, 2015

In the virtual worlds of climate modeling, forests and other vegetation are assumed to bounce back quickly from extreme drought. But that assumption is far off the mark, according to a new study of drought impacts at forest ...

A cataclysmic event of a certain age

July 27, 2015

At the end of the Pleistocene period, approximately 12,800 years ago—give or take a few centuries—a cosmic impact triggered an abrupt cooling episode that earth scientists refer to as the Younger Dryas.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.