NASA Sees Rapid Changes in Arctic Sea Ice

Sept. 13, 2006

Erica Hupp/Dwayne Brown
Headquarters, Washington
202-358-1237/1726

Alan Buis
Jet Propulsion Laboratory, Pasadena, Calif.
818-354-0474

RELEASE: 06-315

NASA SEES RAPID CHANGES IN ARCTIC SEA ICE

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.

For more information about QuikScat, visit:

http://winds.jpl.nasa.gov/missions/quikscat/index.cfm

For more information about NASA and agency programs, visit:

http://www.nasa.gov


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