NASA said the dramatic decrease in ice thickness and coverage over the past 30 years is an important indicator of the health of the Arctic.
Arctic ice is dwindling and more of it appears to be thin, seasonal ice that melts each year, according to NASA.
NASA said Monday that the ice cap appears to be thinning, while the area it covers shrinks as well. The news came from the National Snow and Ice Data Center in Boulder, Colo. NASA said that the finding supports evidence from satellite observations.
This winter marked the fifth lowest for ice coverage on record since satellite monitoring started 30 years ago, continuing a trend of record lows in coverage since 2004, NASA said.
Thin seasonal ice, which melts each year, now accounts for about 70% of ice coverage, up from 40% to 50% in the 1980s and 1990s, according to NASA. Thicker ice, which generally melts after two or more years, now makes up 10% of the winter ice cover, down from 30% to 40%, according to researchers. Seasonal ice averages about 6 feet deep, while the longer-lasting ice averages about 9 feet deep, the researchers reported.
"Ice extent is an important measure of the health of the Arctic, but it only gives us a two-dimensional view of the ice cover," Walter Meier, research scientist at the center and the University of Colorado, Boulder, said in a statement released Monday. "Thickness is important, especially in the winter, because it is the best overall indicator of the health of the ice cover. As the ice cover in the Arctic grows thinner, it grows more vulnerable to melting in the summer."
Coverage area for this winter was 5.85 million square miles, 278,000 square miles less than the average coverage from 1979 to 2000.
A team of researchers led by Ron Kwok of NASA's Jet Propulsion Laboratory in Pasadena, Calif., used two years of data from NASA's Ice, Cloud, and Land Elevation Satellite (or ICESat) to create the first map of sea ice thickness over the entire Arctic basin this year. They found that the average winter volume of Arctic sea ice holds so much water it could fill Lake Michigan and Lake Superior.
Researchers hope their findings will improve understanding of climate change. The world's climate system relies on Arctic sea ice as a sort of air conditioner.
InformationWeek Analytics has published an independent analysis of green IT strategies. Download the report here (registration required).