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Fall 2009 Vol. 9 Number 2



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On Thin Ice

©Trevor Bauer/Vetta Collection/iStockphoto

Clues to Arctic Melt May Be Found
in Declassified Data

The worlds of James Bond and climatology rarely cross paths. But as climate around the globe continues to shift, many are beginning to view climate change as also a national security issue.

This is particularly relevant in the Arctic basin where the loss of sea ice in recent years and the possibility of the basin becoming ice-free during the summer months have raised a number of security, environmental, and economic concerns. Could the intelligence community hold pertinent information to help climatologists and other scientists better understand global climate change and the shrinking Arctic sea ice?

In July, approximately 600 images from intelligence sources showing detailed elements of the melting and freezing cycles of Arctic sea ice were made public by the U.S. Geological Survey, hours after a National Research Council report urged their release. “It was a pleasant surprise to learn that the USGS acted so quickly,” said chair of the committee that wrote the Research Council report Stephanie Pfirman, and chair of the department of environmental science at Barnard College. “Having these images is critical for projecting how Arctic sea ice will change over the next several decades, because they show information at scales, locations, and time periods that is not available elsewhere.”

With the possibility of an open water basin, trans-Arctic shipping between the Atlantic and Pacific is likely to increase, which will impact laws governing oceans and territorial waters, as well as the monitoring and policing of international agreements and search and rescue. Other consequences of diminished ice cover include easier access to potential fossil fuel deposits and other mineral resources, requiring the development of appropriate policies and infrastructures, and strain on wildlife habitats and shifts in ecosystems.

“Better forecasts of sea-ice conditions can help officials and leaders prepare for and adapt to the impacts of climate change and minimize environmental risks associated with increased development,” Pfirman added.

The committee called for release of the images because few observations are available at times and scales necessary to understand processes involved in the melting and freezing of the ice. U.S. Coast Guard Cutter Healy in the Arctic, photo courtesy U.S. Geological SurveyCollecting ground-based observations via manned-drifting stations is challenging due to changing environmental conditions, and observational aircraft flights in that region are difficult and expensive. Moreover, the only previous satellite images of Arctic sea ice that were readily available to the public were 15 to 30 meters resolution, making them too coarse to capture details. The newly released images are at 1-meter resolution, allowing scientists to see processes unavailable in other data.

Scientists can now learn more about the rapid loss and transformation of Arctic sea ice by examining the distribution of ice thickness and how stress and strain lead to the pattern of cracks and other features in the ice. In addition, the new images could help show how pools of water, called meltwater ponds, begin to form in ice floes and expand in the ice over summer. Because meltwater ponds are darker than Arctic sea ice, they absorb more light and enhance floes’ rate of melting.

Collection of the images started in the 1990s as part of a program in which scientists recommended gathering and archiving high-resolution classified imagery from intelligence sources at environmentally sensitive locations around the globe. The goal was to ultimately declassify and distribute the images to the broader scientific community. However, these images remained unavailable until July when the USGS released them. The images are available at <gfl.usgs.gov> — Jennifer Walsh


 Scientific Value of Arctic Sea Ice Imagery Derived Products. Committee on the Scientific Value of Arctic Sea Ice Imagery Derived Products and Committee on Climate, Energy, and National Security; Polar Research Board; Division on Earth and Life Studies (2009, 48 pp.; ISBN 0309-13763-2; available from the National Academies Press, tel. 1-800-624-6242; $15.00 plus $5.00 shipping for single copies).

The committee was chaired by Stephanie Pfirman, a professor in environmental and applied sciences and chair of the department of environmental science at Barnard College, New York City.



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Copyright 2009 by the National Academy of Sciences