Story posted August 03, 2005
Deep under the expansive canopy of trees in Harvard Forest
-- a 3,000-acre tract in northern Massachusetts -- stands a wooden shack. From the outside, it looks like a rustic skier's hut. Inside, it's another story.
The structure contains hundreds of thousands of dollars of scientific equipment being used for environmental research. The site is part of a network of ecological research stations located within the forest, which is owned and operated by Harvard University.
This summer, a new piece of equipment will be installed in the research station - a highly sensitive device for measuring relative amounts of oxygen and carbon that enter and leave the atmosphere above and below the forest canopy.
The instrument has been built by Assistant Professor of Physics and Astronomy Mark Battle, whose research on atmospheric composition and climate change has taken him from the equatorial Pacific Ocean to the South Pole.
The research project is designed to help Battle refine estimates of the amount of carbon the forest will absorb in the future, and gain a better understanding of exactly how ecosystems process nutrients. The information will add to the body of scientific knowledge being gathered worldwide to understand and predict global warming.
"Harvard Forest is perfect for this kind of work." notes Battle, "There is an active air-sampling program already in place and an ecosystem that already is thoroughly characterized. The data from these other studies will be essential for interpreting my own measurements."
Battle's study, which will take place over several years, attempts to improve measurements of terrestrial sources and sinks of carbon. Specifically, his instrument measures Harvard Forest air samples for their levels of oxygen and carbon dioxide against tanks of "standard" air that have been calibrated on independently maintained scales.
Over time, he will be able to see how increases and decreases in CO2 correlate with changes in oxygen levels.
"One of the best ways to determine terrestrial CO2 uptake is by measuring atmospheric oxygen levels, since plants that take up CO2 are releasing oxygen," explains Battle. "What we don't know is the exact relationship between the uptake of one gas and release of the other. If a plant stores carbon when making leaves, we expect it to release a different amount of oxygen than if it is making roots, for instance. We are trying to determine the relevant ratio of the two processes over a long period of time."
Ultimately, Battle hopes his data will lead to more accurate prediction of the long-term buildup of greenhouse gases in the atmosphere and temperature change.
The instrument has been three years in the making - with help from several Bowdoin student-research assistants. Once in place, sometime in August, 2005, Battle will be able to monitor the machine remotely by a laptop computer with a DSL hookup to the research site.
"Britt Stephens (of the National Center for Atmospheric Research) built the first system like this a few years ago, and I know of only one other running in the world right now," notes Battle "Thanks to its location, ours will provide a unique data set which I expect will be of interest to a fairly broad community."
The project is made possible through institutional laboratory startup funds and a Kenan Fellowship. "There's a big investment of time and money get an instrument like this up and running with the requisite precision," adds Battle. "This is a great example of institutional support coming to life. I feel very lucky to be afforded such an opportunity."