NASA Sees Rapid Changes in Arctic Sea Ice
by Sean Chamberlin - Wednesday, 13 September 2006, 07:03 PM
  Publications - NASA Sees Rapid Changes in Arctic Sea Ice
September 13, 2006

Summer Arctic ice. Credit: NASA
Summer Arctic ice. Credit: NASA
NASA Feature  -  Animation

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.

The whole of the sea surface is made of forming sea ice. Credit: NASA
The whole of the sea surface is made of forming sea ice. Credit: NASA
"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/

Re: NASA Sees Rapid Changes in Arctic Sea Ice
by Ana Albarran - Sunday, 17 September 2006, 06:54 PM
 

     What will happen if the sea ice cover continues to decline? Everything is connected and affect the earth's surrounding. For example, with the global warming or the green house gases and the Artic sea ice melting affects the animals in the sea because if the ice does not melt completely, it flows and cuts the food in the sea for the animals. Everything that happen in our environment affect people and animals.

     This is something new to me. This is the first time I hear of the Artic sea ice melting and that in the future could be a problem for people. For example, the news from NSIDC reported that "in the reduction in summer ice cover likely plays a role by reducing surface albedo and thereby increasing the heat input into the ocean. A warmer ocean will subsequently delay the onset of autumn freeze-up." I am not sure of what does this means, but I think that in autumn would be colder of what it is now.

     If you could explain to me what would be the causes and the results about the Artic sea ice, I will appreciate it. Thank you.