SHEBA's ultimate goal is to better understand the climate of the Arctic so that forecasts of global climate change can be improved, according to Mike Ledbetter, NSF program director for Arctic system science.  The $19.5 million project, also funded by the Office of Naval Research, is coordinated by the University of Washington's Applied Physics Laboratory.  NSF is also supporting $2 million worth of other science related to SHEBA.

     The Canadian Coast Guard icebreakers Louis S. St. Laurent and Des Groseilliers will steam to the SHEBA site 300 miles north of Prudhoe Bay, Alaska -- approximately 75 degrees north and 143 degrees west -- arriving about October 1.

     More than a century after Norwegian Fridtjof Nansen froze his specially designed ship, the Fram, into the ice of the Arctic Ocean and left it to drift for three years of scientific exploration, the Des Groseilliers will be left in place to serve as a floating dormitory and science quarters.  It will be surrounded by small huts and experiments on the sea ice, along with an airplane skiway for supply flights throughout the year. The Louis S. St. Laurent departs the site about October 15.

     Climate modelers currently differ over the future of the Arctic's pack ice.  If carbon dioxide doubles in the atmosphere, an occurrence possible in less than a century, some models predict that the pack ice could disappear completely; others suggest less shrinkage.  All models concur, however, that Arctic pack ice will play an important role in climate change.

     The varied landscape of sea ice -- rent by cracks, pathways of open water called leads, pressure ridges tens of meters thick and other fantastic forms -- is constantly deformed and shifting. The ice also chills the atmosphere by blocking warmth from the sea in winter and reflecting most incoming sunlight in summer. "More than half the Arctic pack ice melts and refreezes each year, but even the most sophisticated computer models cannot simulate this change," said Richard Moritz, SHEBA project office director at the University of Washington.

     Pack ice looms large in several realms, its fate bearing upon shipping routes, petroleum extraction and a rich marine ecosystem embracing whales, polar bears, fish and plankton, a web of life key to the livelihood of Arctic peoples.

     SHEBA scientists plan to trace the transfer of energy between the atmosphere, sea ice and ocean waters over an entire year of freezing and melting.  "SHEBA's hallmark is to gather a comprehensive data set documenting all the variables and processes at work," Moritz said.

     In addition to the frozen-in ship, the project will employ a fleet of icebreakers, research aircraft and balloons, a U.S. Navy nuclear submarine and satellites.  More than 50 scientists from universities and agencies such as NASA and the Department of Energy will participate, along with researchers from Japan, Canada and the Netherlands carrying out related studies.

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• Global Warming
• Climate
• Oceanography
• Ice Ages
• Geography
• Tundra

• Ice shelf
• Ocean current
• Iceberg
• Greenland ice sheet
• Climate
• Geologic temperature record