Collaborative effort leads to improved landscape models of a changing tundra
Making well-informed computational models of an ever changing, vast Alaskan landscape presents challenges that Oak Ridge National Laboratory researchers are working to overcome.
The Next Generation Ecosystem Experiments (NGEE) Arctic project, a collaboration between ORNL and other national laboratories and universities, seeks to investigate how permafrost degradation and associated effects on hydrology, landscape evolution and vegetation dynamics will affect climate. Researchers hope to contribute this information to improving climate models of the Arctic. Today's models do not include all the physical and biological processes of the landscape and there are processes operating at small scales where understanding is inadequate.
"Current models can be improved by identifying areas where climate predictions are sensitive to biogeochemical processes," said Peter Thornton, climate modeler. "The processes that are going on in the Arctic are dependent on details in the landscape on scales of feet to miles."
Given its unique model-driven nature, NGEE will likely span 10 to 12 years, but with informed predictive abilities, it could have an impact that exceeds centuries.
"There's not much modeling of the highly coupled landscape processes in Alaska and the Arctic, so we want to study processes that are important to climate modeling to contribute to current and future models," said Stan Wullschleger, NGEE project coordinator and ORNL plant physiologist.
As researchers from across the country come together to work in one location, they will be striving to answer a circular question: How will a changing climate affect the Arctic, and how will this in turn impact the planet's climate?
"For millennia, carbon has been locked into the frozen soil of Alaska," said Rich Norby, a member of the NGEE team and ORNL physiological ecologist. "With warming, permafrost could thaw and release this stored up carbon. It's a real concern for the climate, but our understanding is incomplete."
In preparation for the project, ORNL researchers are working to translate what they've done in the past to what they are now learning about the Alaska tundra. Alaskan systems are complex and interconnected where a cascading effect leads to one change, which leads to another and then to another.
One piece of this enormous puzzle is getting a lay of the land and talking with community leaders to figure out what field study sites are most representative of Alaska and the Arctic.
"It makes a tremendous difference to be able to go to the sites in Barrow, Nome and elsewhere in Alaska to get an idea of where we'll be conducting research," said Norby.
Thornton agrees. "It's also important for modelers to be on the field site to have an understanding of the dynamics; otherwise, the models put too much faith or ignore important aspects of the system," Thornton said.
Beyond the magnitude and implications of the science behind this project, researchers find themselves struck by the Alaskan landscape. Norby admires the awe-inspiring vastness. Wullschleger values the diversity of the people and enjoys listening to the stories they tell about how ecosystems have changed over their lifetimes.
ORNL is in charge of the overall coordination of the project and will also ensure that plant and microbiology processes are incorporated into climate models. Partners at Los Alamos, Lawrence Berkeley, and Brookhaven National Laboratory and the University of Alaska Fairbanks make unique contributions in other areas, such geomorphology, geophysics, hydrology, landscape evolution, and modeling.
"We'll be working at the microscale, macroscale, global scale and just about everywhere in between," Norby said.— Emma MacMillan, Nov. 23, 2011