Arctic Research Offers New Clues to Global Warming

A University of Cincinnati assistant professor of geography heads a project that is working to improve the reliability of global warming predictions.

An international scientific panel recently concluded the Earth's climate has been warmed substantially over the last 50 years by greenhouse gases produced by the burning of fossil fuels. The scientists also said temperatures could go higher than previously predicted if emissions are not curtailed.

Wendy Eisner, UC assistant professor of geography at University of Cincinnati, heads a project that is examining Arctic thaw lakes, (Arctic water holes) and their descendants, drained lake basins. Thaw lakes, which form on top of the ice-rich tundra, cover about 20 percent of the Arctic Coastal Plain. Their drained basins cover an even greater portion of the region. These lakes and their drained basins may hold important clues about global warming.

Satellite images of the thaw lakes look a lot like Swiss cheese, blotted with dark holes randomly spaced. The images Eisner studies are from a satellite flying 438 miles over the Earth. She also studies the lakes up close. In August, she trekked through mud, rain, snow and -- sometimes -- swarms of mosquitos, to learn more about the thaw lakes and drained lake basins.

"It is not known how much of the landscape is made of drained thaw-lake basins," says Eisner. "To date, no systematic examination of drained thaw-lake basins has been undertaken across the Arctic Coastal Plain. No one knows much about how the lakes form or how or why they change."

She and UC geography faculty members Robert Frohn and Kenneth Hinkel, along with colleagues James G. Bockheim of University of Wisconsin, Kim Peterson of University of Alaska at Anchorage and Frederick Nelson of University of Delaware hope to fill that void and find out more about the impact these drained thaw lakes and their predecessors may have on global climate.

The six-member, interdisciplinary team is collaborating in a three-year study funded by a $454,849 National Science Foundation grant.

The team will return to Alaska in April 2001 for further study and will use an 800-pound drill called a "Big Beaver" to collect soil samples. This summer, samples taken manually reached down to 18 inches in the permafrost, but the mechanical drill will reach eight to nine yards deep, cutting right through solidly frozen ground.

A primary focus of the team's investigation is determining the amount of carbon stored in the drained lake basins. Arctic soils and peatlands are significant sources of carbon dioxide and methane, both potent greenhouse gases. Carbon is stored in the basins as frozen peat, but recent studies indicate that the soils may be releasing greenhouse gases faster than they can store them.

"We think this could turn out to be a positive feedback effect, where as the Arctic warms, these soils thaw and release greenhouse gases, which then contribute to further global warming. The question is: How serious could this problem become?" says Eisner.

Carbon levels are not the end of the story, however. The team will also use carbon 14 analysis, data collected from ground-penetrating radar and other tools to analyze what has happened over thousands of years with the thaw lakes and basins.

"We will examine past climate changes and the rate at which carbon has accumulated in the soil over time," said Eisner. That way the team can make better predictions based on what has happened in the past.

Seen here are University of Wisconsin postdoctoral fellow Nick Balster with UC master's student Elizabeth Wolfe and UC assistant professor of geography Robert Frohn in the helicopter the team used for field reconnaissance.