Sep. 12, 1997 Winter has already begun for a crew of four who will spend the entire season atop the Greenland ice sheet studying the weather at a remote outpost called Summit. The camp at the apex of the ice sheet, where the sun will set in November and not reappear until late January, is the first attempt supported by the National Science Foundation to over-winter in Greenland.
"This is the first time we will be able to examine the entire annual cycle of air and snow chemistry," said Mike Ledbetter, program manager for Arctic system science at NSF. "Ultimately, it will help us to better interpret climate history and how human beings are affecting climate."
If the project goes well, NSF may explore establishing a permanent year-round camp at Summit. Up to now, winter at Summit has been like the dark side of the moon for scientists, who have not been able to stay on the scene to study the snowfall in the winter. They do not even know when most of the snow falls.
The structures and airplane skiway that comprise the station at Summit cluster atop a broad swell of ice cap almost two miles thick, 481 miles from its supply point on Greenland's west coast. NSF extracted the Northern Hemisphere's longest ice core at Summit from 1989-1993. The core drilled by researchers with The Greenland Ice Sheet Project 2, along with another core drilled nearby by European scientists, furnish an icy archive of over 100,000 years of climate information. The annual layers in the ice cores store a finely detailed atmospheric record, as well as traces of volcanic eruptions, forest fires, ocean storms, atomic bombs and pollution.
"The falling snow, which eventually becomes compacted into ice, stores information about the atmosphere at the time it fell -- the water vapor, temperature and dust content," said Jack Dibb, the University of New Hampshire climatologist who heads the wintering project. "The Greenland ice cores have already shown us that there were unexpectedly rapid and dramatic shifts in climate. How closely do these changes in ice composition actually record the changing chemistry of the atmosphere? The idea is to turn these records into a history of the atmosphere's composition."
Dibb's project this year will assist this translation. "Our goal during this first year-round occupation of Summit will be to determine what controls the composition of air just above the ice sheet, to see how closely the composition of snow reflects that of the air, and to understand how air and snow exchange water, energy and chemical compounds through the winter," Dibb said.
The wintering crew--an electronics technician, a mechanic, and two science technicians--will spend most of their time at Summit in "The Greenhouse," a one-story, 32-by-36 foot building serving as combined bunkroom, living room, and laboratory. The structure rests on skis and can be moved from year to year to avoid burial by snow. The winter-overs will have electronic mail but not telephone contact with the outside world. A supply flight in November will rotate one crew member, with another such flight in February. The University of Nebraska's Polar Ice Coring Office provides logistics for the effort.
Winter temperatures at Summit can drop to -60 Fahrenheit or lower, hampering attempts at winter research with automated instruments in the past. This winter, however, the station's crew will be on hand if something goes awry.
If this winter's experiment goes well, NSF will explore setting up year-round quarters at Summit for a wider range of studies in future years, possibly with international partners. This spring, at a workshop in Greenland sponsored by NSF and the Danish Research Commission, scientists from four countries explored the potential to use a year-round station at Summit to study snow deposition, atmospheric chemistry, the ozone hole, magnetospheric physics, and other disciplines.
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