Recording the Life Cycle of an Arctic Ice Sheet
For more than a year, people clad in insulated overalls, "bunny boots," and thick parkas have scuttled over an Arctic ice floe, measuring its growth, decay, and the impact the ocean and atmosphere have on its life cycle.
Last Saturday, research teams with the SHEBA (Surface Heat Budget of the Arctic Ocean) project returned home, bringing to a close the most ambitious civilian Arctic Ocean study the United States has ever undertaken.
The project's main purpose is to help improve climate-change forecasts by plugging wide gaps in scientists' understanding of how the ocean, ice, and atmosphere in the Arctic exchange heat.
Although much of this "heat budget" data will take years to analyze, some results already show promise of improving weather forecasts in areas affected by Arctic weather patterns.
The project also appears to be breaking the ice for future large-scale Arctic studies. On Tuesday, Congress approved a 69 percent increase in the National Science Foundation's Arctic-systems science program, from $32 million in fiscal 1998 to $54 million in 1999.
SHEBA "helped focus some attention on the Arctic as a place where there are some real problems that require a big coordinated approach to solve," says Michael Ledbetter, who heads the NSF's Arctic science program.
For the 170 researchers and technicians involved, SHEBA has been a bonanza. Typically, such experiments run for only a month or two, notes Don Perovich, the project's chief scientist. "That's what's really exciting about SHEBA - we got to see the whole movie," he says, from the growth of the ice last winter to its summer melt and subsequent regrowth this fall.
It was a movie with surprising twists. One of the first surprises: The ice was much thinner when the Canadian icebreaker Des Groseilliers arrived Oct. 2, 1997, than either historical data or computer models led the researchers to believe. Instead of the 2.5-to-3-meter-thick floes they expected, the scientists could only find floes 1.8 meters thick within range of the resupply plane.