September 19, 1997
Ships depart to launch Ice Station SHEBA in the Arctic Ocean
Two icebreaking ships are expected to depart Tuktoyaktuk, Canada, this weekend to establish Ice Station SHEBA in the Arctic Ocean, launching the largest and most complex science experiment ever supported in the Arctic by the National Science Foundation.
The University of Washington’s Richard Moritz, director of the ice station’s project office headquartered at the UW’s Applied Physics Laboratory, is now on board the ice breaker that will be frozen into the pack ice of the Arctic Ocean and left to drift as a floating science platform for 13 months.
The target of the $19.5 million Surface Heat Budget of the Arctic Ocean project: charting the fate of the great canopy of pack ice about the size of the United States, which seals off the Arctic Ocean.
SHEBA’s ultimate goal is to better understand the climate of the Arctic so that forecasts of global climate change can be improved. 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 Oct. 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 Oct. 15.
Climate modelers currently differ over the future of the Arctic’s pack ice, Moritz says. 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,” Moritz says.
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 theatmosphere, 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 says.
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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