LOS ANGELES, Aug 7 (Xinhua) -- Using data from the Arctic Boreal Vulnerability Experiment (ABoVE), a new study shows that the Arctic carbon cycle is speeding up, and is now at a pace more characteristic of a North American boreal forest than of the icy Arctic. Carbon in Alaska's North Slope tundra ecosystems spends about 13 percent less time locked in frozen soil than it did 40 years ago, according to the new study recently published in the latest issue of journal Science Advances. "Warming temperatures mean that essentially we have one ecosystem -- the tundra -- developing some of the characteristics of a different ecosystem -- a boreal forest," study co-author Anthony Bloom of NASA's Jet Propulsion Laboratory in Pasadena, California, said in a press release. "While various factors regulate how fast this transformation will continue to occur, studies using Landsat and MODIS satellite imagery with field measurements over the past decades have observed a northward migration of shrubs and trees." Since Arctic stores large amounts of carbon in frozen soil, any change in the amount of carbon released in this region is of huge global concern. The research team combined data from more than 40 years of carbon dioxide surface measurements from the U.S. National Oceanic and Atmospheric Administration (NOAA)' Barrow, Alaska Observatory with a standard ecosystem carbon balance model to determine the rate at which carbon is moving in and out of Alaska's North Slope. Models alone previously indicated an increase in the speed of the carbon cycle, but the addition of long-term satellite, airborne and surface data to the equation shows that those models were underestimating just how significant the increase was. The Arctic carbon cycle is a delicate balance of carbon being released into the atmosphere and carbon being removed from the atmosphere. Disruptions to this balance have implications well beyond the Arctic, researchers say.
|