NASA: Satellites and Submarines Give the Skinny on Sea Ice Thickness

[OKIsItJustMe]

http://www.nasa.gov/topics/earth/features/seaice_skinny.html

Satellites and Submarines Give the Skinny on Sea Ice Thickness 09.01.09

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Analysis of the new record shows that since a peak in 1980, sea ice thickness has declined 53 percent. "It's an astonishing number," Kwok said. The study, published online August 6 in Geophysical Research Letters, shows that the current thinning of Arctic sea ice has actually been going on for quite some time.

"A fantastic change is happening on Earth — it's truly one of the biggest changes in environmental conditions on Earth since the end of the ice age," said Tom Wagner, cryosphere program manager at NASA Headquarters. "It's not an easy thing to observe, let alone predict, what might happen next."

Sea ice influences the Arctic's local weather, climate, and ecosystems. It also affects global climate. As sea ice melts, there is less white surface area to reflect sunlight into space. Sunlight is instead absorbed by the ocean and land, raising the overall temperature and fueling further melting. Ice loss puts a damper on the Arctic air conditioner, disrupting global atmospheric and ocean circulation.

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Kwok and Rothrock compared the submarine data with the newer ICESat data from the same study area and spanning 2003 to 2007. The combined record shows that ice thickness in winter of 1980 averaged 3.64 meters. By the end of 2007, the average was 1.89 meters.

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Patterns of average winter ice thickness from February to March show thicker ice in 1988 (above), compared to thinner ice averaged from 2003-2008 (below). Thickness information in Antarctica is limited to an irregular polygon shape that outlines the area where declassified submarine data are available. Credit: Ronald Kwok/NASA