Researchers are studying permafrost in Alaska to get long-term data on the release of carbon dioxide as the result of weather changes.
The team is led by Dr. Houston Miller, Professor of Chemistry at the George Washington University. It includes GWU students, researchers from NASA Goddard Space Flight Center and the University of Alaska, Fairbanks. Funded by a grant from NASA's Terrestrial Hydrology Program, the team is combining satellite measurements, climate modeling, and ground-level measurements of greenhouse gas concentrations during seasonal permafrost melting seasons.
According to Dr. Miller, “[Our project is] a multi-disciplinary, multi-scaled study to measure methane (CH4) and carbon dioxide (CO2) above thawing permafrost at three sites, each representing a different ecosystem near Fairbanks, AK. We have designed a unique and comprehensive array of ground experiments at these sites that will record permafrost depth and subsurface structure, meteorological data, and concentrations of key greenhouse gases during seasonal ground thaw of the active layer in the summer.”
Dr. Miller's group has developed Raspberry Pi-controlled devices that read temperature, air pressure, radiation, and methane. The K-30 CO2 sensor will measure carbon dioxide, one of the two greenhouse gases (GHG) that are released as permafrost thaws.
“We refer to this effort as a pilot study as we will collect observations near Fairbanks, AK with the intent to expand our observational network in the future to other sites in North America, which will aid in the monitoring of changes in GHG emissions in the Arctic as well as complement and help interpret data collected by space-borne instruments, such as GOSAT, IASI, and AIRS,” he continued.
“This is the first time that these types of measurements have been combined to provide a holistic view of the evolution of, and the atmospheric response to permafrost thaw. These data will allow us to estimate emission fluxes of carbon from the thawing permafrosts,” he said.
When asked about his early findings, Dr. Miller said, “The data below is a pretty good summary of the duel sink/source roles in a very tiny portion of Alaska. Extrapolation to a large land area is challenging, but the data collected from this and other sites suggests that the thawing season is getting longer and the area of decreasing permafrost is increasing.”
The graph shows some sample data from last year comparing the K-30 sensors with expensive laser-based sensors The yellow is a K-30 sensor at ground level. The explanation for the large night-time concentrations is that during the day the sphagnum moss under-story acts like a CO2 filter of any out-gassing from the bog. At night, photosynthesis shuts down and the bog becomes a source.
"In the daytime CO2 levels are often below 400 ppm whereas the night time levels are as high as 900 ppm," Miller said.