To research the wintry tundra near Denali National Park, scientists often turn to a four-legged mode of transport to reach their field — sled dogs.
At Eight Mile Lake, just outside the Park boundaries, lies an important study site for NASA. Dr. Ted Schuur from the University of Northern Arizona operates a suite of instruments that measures the movement of CO2 and methane from the tundra ecosystem to the atmosphere. This “flux tower” helps us estimate how fast the plants of the tundra are growing each summer, how much carbon they remove from the atmosphere, and how much carbon returns to the atmosphere because of respiration and decay of organic matter in the soils.
In January, Dr. Dave Schirokauer, a National Park Service scientist and a collaborator on NASA’s Arctic Boreal Vulnerability Experiment, took me out to Ted’s site on Dave’s personal dog sled.
Competitive sled dogs are typically 2 to 5 years old. Dave’s dogs are special. They’re 5 to 14 years old, retired from competition (two of them ran the Iditarod in years past), but they retain their passion for running. Percy, the lead dog because she’s strong and intelligent, jumps for joy, anticipating our start.
The day we went mushing was windy but unusually warm, hovering just below freezing, which is about 40 degrees warmer than normal for January in interior Alaska, where climate is warming twice as fast as the global average. So these measurements of plant growth, respiration, and methane release are important. Ground measurements here and at a dozen other locations in Alaska and Canada will be used with measurements of CO2 and methane from the NASA Airborne mission CARVE, and the Orbiting Carbon Observatory, in global models to better understand how the ecosystem is changing.
I asked Dave about the importance of this research to Denali National Park, and the people in Interior Alaska:
The North side of Denali is underlain by permafrost, he said — in fact, this area is the southernmost extent of continuous permafrost. Its presence is one of the park’s resources in and of itself. Furthermore, it drives or affects many of the biophysical process that the park was created to preserve. On a local and regional scale, permafrost affects wetland hydrology (like nest habitat for swans), plant communities and wildlife habitat, and the fire regime. On a global scale, carbon sequestered in the frozen ground that has been out of atmospheric circulation for centuries has the potential to be released as soils warm and microbial activity turns the formerly frozen carbon into carbon dioxide and methane.
As measured in a local bore hole and by instruments run by Dr. Schuur, permafrost in our neighborhood is thawing, which is of great interest and concern to the local residents, visitors and natural area managers. The NASA ABoVE research campaign will shed light on this process and help us understands and adapt to a changing northern landscape.