Here, near the town of Cherskii, ESRL researchers, Zimov, and other collaborators have managed to collect more than a year’s worth of nearly-continuous data on the atmospheric concentration of methane, a powerful greenhouse gas. Zimov travels to the research site at least a couple times a month, repairs the power line as needed, downloads data onto a thumb drive, and sends it back to ESRL through the web.
“The data are very good,” said ESRL’s Ed Dlugokencky (Global Monitoring Division). “This is going to be a great site for understanding the Arctic processes that affect atmospheric methane.”
Methane is a potent greenhouse gas that’s emitted directly by some human activity, by microbes in wetlands and permafrost, and through other processes that can be amplified by warming. Many researchers are concerned that someday, a dangerous feedback cycle will occur as warming triggers the release of methane that’s tied up today in wetlands and frozen soils. “The methane feedback is a big, open question for science right now,” Dlugokencky said.
In a paper published last fall, he and colleagues reported that global methane data do not yet show evidence of a positive feedback. Dlugokencky’s team analyzed air samples collected in flasks and from towers around the world. Methane levels did increase in 2007 and 2008, following nearly a decade of near-zero growth. But the spatial pattern of those increases was most likely related to unusual weather patterns—first, anomalous warmth in the Arctic in 2007, and then very high precipitation in the tropics in 2008. In 2007, forest fires also contributed to the growth in methane, the researchers reported.
Despite ESRL’s extensive air sampling network and ability to study global trends, researchers still don’t understand the details of the methane cycle, Dlugokencky said. “We need better data on the ground, to figure out the processes that are going on that relate to what is going on in the atmosphere.”
Such data would help global climate modelers refine models to better depict the reality of the methane cycle, and would help scientists and others understand what to expect in the future.
The Cherskii site seems ideal for studying such land-air processes, Dlugokencky said. Last year, his colleague Andrew Crotwell (ESRL’s Global Monitoring Division) traveled with a University of Alaska researcher to the remote site, and installed the instrument that continuously measures methane, wind speed, and direction.
It was not an easy install, Crotwell admitted. His group first had to retrofit an old shack once used to warm the tundra enough to punch in fence posts and to smoke fish. Then, after the equipment was carefully installed, the scientists hooked the “laboratory” to an old tank to pull it more than a mile away to a new site. The shack caught on a tree stump and flipped.
Crotwell un-installed the equipment, pulled it out of the shack, and reinstalled it after the team managed to right the structure. It took hours, Crotwell said, and the mosquitoes were nearly unbearable.
The data, however, already make the effort seem worthwhile. The tower site bears an anthropogenic signal only rarely, when winds sweep down from Cherskii, which lies 40 km to the northeast. “When the wind comes from the lowland sector to the northwest, we see methane enhancement from local wetlands,” Dlugokencky said.