A team of scientists completed the first drilling session of the National Science Foundation's West Antarctic Ice Sheet Divide (WAIS Divide) Ice Core Project last month. The team, including UNH member Joe Souney, extracted a 580-meter core, the first section of a 3,456-meter ice core that will be used to examine the greenhouse gas record of the past 100,000 years. The goal of the study is to better understand how climate functions so accurate models can be made to predict the effect of human greenhouse gas emissions.
"If you don't know your past, you don't know your future," said Mark Twickler, manager of the project and part of the UNH Institute for the Study of Earth, Oceans and Space (EOS).
One of the key questions the scientists are trying to answer is whether carbon dioxide concentrations increase before, during or after natural temperature increase. Kendrick Taylor, chief scientist of the project, said studying the time lags between temperature and carbon dioxide requires an ice core with distinguishable layers, like the WAIS Divide core.
While other ice cores extending as much as 650,000 years back in time have been extracted before, the WAIS Divide ice core is unique in the number of individual layers that can be distinguished.
"We'll be able to differentiate layers 40,000 years back in time," said Taylor.
By examining how carbon dioxide changes affect climate, Taylor said they can better understand how the mysterious climate machine worked before human influence.
"It's another piece in the puzzle, and the more pieces we have the more complete the picture," said Twickler. "It's amazing how little we know about climate. Hopefully our core will show a connection between temperature and greenhouse gases and how they affect the natural climate system."
The scientists also want to compare the WAIS Divide ice core data to data from similar ice cores from Greenland. This would enable them to compare climate changes between the northern and southern hemispheres to see how similar or different they are.
"It will help us more clearly understand what's driving these changes," said Joe Souney, project director and also a part of UNH's EOS. "We'll have a better understanding of how the southern hemisphere's climate varies."
Using the data from the ice cores, they can develop computer climate models and test them for accuracy. These climate models can then be used to predict the amount of climate change from human greenhouse gas emissions.
"You first try to reproduce how climate has changed in the past with computer models," said Souney. He said they need to be certain and better understand the past in order to make accurate predictions about the future.
"The truth is I don't really care what the Antarctic climate used to be," Taylor said. Instead, he said he is interested in modeling the future, and he compared looking at greenhouse gases in the ice core to doing research in the library.
The ice core is currently on its way to the National Ice Core Laboratory, which is run by the United States Geological Survey, in Denver, Colo. Analysis, which includes examining everything from crystal structure to chemistry, will begin in June. Some tests have already been performed in the field, and the core has already been dated.
The project took over 15 years of preparation, and it is expected to continue until at least January 2010. There are at least three more ice core drilling seasons to complete, along with measurements and analysis. When the ice coring is complete, Twickler said they want to sample bedrock.
The stormy conditions at the drilling site only allow for a 40-day window each year when scientists can do field work. Twickler said this year's conditions were worse than the previous two years, making the working conditions and logistics more difficult.
Souney, who recently returned from Antarctica, said the drilling is done in an arch-like facility that protects the drill from the elements. However, there were still some days when the scientists were unable to walk from their camp to the drill because of strong winds and low visibility.
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