I Spy the Arctic

The U.S. government has released high-resolution photographs of the Arctic taken by a spy satellite. Just a few hours before their release, the National Academy of Sciences recommended that the photos be made available to scientists and the general public in order to study climate change – demonstrating the swift action of the government.

The resolution of the photographs is about 1 yard, a vast improvement over previous surveys, where the resolution was 30 meters. As Deborah Zabarenko writes in a Reuters article, such a fine level of detail will allow scientists to study small pools of water on top of the ice, called melt pools, which hasten the melting of the ice due to their high albedo levels. Together, all of the pools cover some 30% of Arctic ice, yet individually, they are too small to be noticed by less advanced technology.

The photos of Arctic sea ice are available to the public at http://gfl.usgs.gov/ArcticSeaIce.shtml. There, you’ll find links to six websites, each featuring photos, posters, and data for a particular site in the Arctic.

Barrow, AK. © USGS
Barrow, AK. © USGS

This photo of the coast of Barrow, Alaska, a town situated on the Beaufort Sea, is particularly dramatic. A commenter asked on a previous post whether I had any idea how this summer’s ice coverage would turn out. Based on current trends, it will probably be smaller than in previous years. According to the National Snow and Ice Data Center, the ice cap has been shrinking 3.3% a year since the 1980s. Last summer, global warming skeptics brandished evidence that the ice cap had actually grown in size. But in reality, though the 2008 summer ice did cover more area than in summer 2007, that ice was thinner, younger, and melting quickly. Young ice has been becoming more common than old ice, since so much of it melts away after each summer. On the contrary, though, some people think old ice may soon make a comeback, since its disappearance in 2008 was due to an unusually strong trans-polar drift, which melted the ice. Thus, the actual extent of this summer’s ice is still an unknown, but it will likely continue the trend of shrinking ice caps.

For more graphs and information on the Arctic ice cap, check out the NSIDC’s website.

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