Published on 03/27/08

UGA researcher questions carbon-monitoring methods

By Faith Peppers
University of Georgia

Monique Leclerc is testing a theory that could turn the science of carbon measuring on its ear. If her theory proves true, it could have far-reaching implications from Wall Street to the rain forests.

"For more than a decade, I've studied the exchange of carbon between ecosystems and the atmosphere. The approach now considered our method of choice ‘par excellence’ needs substantial rethinking," said Leclerc, a University of Georgia College of Agricultural and Environmental Sciences biometeorologist.

"The current model of quasi-ad-hoc carbon-exchange monitoring stations limits in-depth studies," she said, "particularly for large terrestrial ecosystems, including forests, wetlands and grasslands ecosystems that cover a large portion of the Earth's surface."

Expanding the way data on carbon sequestering is gathered could drastically change the common carbon sequestration estimates from terrestrial ecosystems that feed into local and regional assessments, mitigation and remediation and even the basis for carbon credits traded on international markets.

To improve the data collection system in the southeastern United States, the U.S. Department of Energy awarded $900,000 to Leclerc and colleagues at the Savannah River National Laboratory and the National Oceanic and Atmospheric Administration.

The group will harness cutting-edge technologies to generate new information about the carbon cycle. "This will give us more solid, valid data," Leclerc said.

Our lab "has an excellent existing infrastructure and sees a genuine opportunity to refine our understanding, measurement methods and protocols of data analysis associated with the magnitude of carbon uptake by terrestrial ecosystems," she said.

The data will be entered into regional models. This will enable scientists to create more accurate simulations of how the climate changes. “This also tells us how well our proposed or enacted solutions are working out,” she said.

Leclerc plans to work literally day and night. She plans to test her theory on reasons behind the inadequacy of the current methods to determine the amount of gases exchanged between the surfaces (forests, agriculture, cities) and the atmosphere.

"Plants don't stop working at night,” she said. “We need to measure accurately the amount of carbon dioxide given off at night by the vegetation. Between 40 percent and 60 percent of the net carbon exchange between the forests or crops and the atmosphere happens (at night).

"My greatest hope is that this project will help us get a more reliable picture of the amount of net carbon sequestered on a daily, seasonal and annual basis," she said.

Central to their project is the creation of a unique carbon flux super site at the SRNL near Augusta. Scientists agree that this area is one of the most productive regions of the U.S. and accounts for 48 percent of the carbon uptake in the country.

At Leclerc’s latest site, “many towers and an excellent infrastructure, coupled with a fine group of scientists, have played in our favor,” she said. “But where these tall towers are placed is as critical as the interpretation of the data collected on them.”

Leclerc is particularly interested in the coupling between atmospheric ‘rivers’ of fast-moving air hundreds of meters above the surface and how they impact and skew the interpretation of the nighttime CO2-atmosphere exchange.

Researchers think that measurements at this new location add value to the international and national monitoring networks. It fills the information gap for the highly productive region of the U.S. on the net ecosystem exchange between the existing flux-monitoring stations at Duke University and sites in Florida.

Faith Peppers is the director of public affairs with the University of Georgia College of Agricultural and Environmental Sciences.