Wet tundra ecosystems are well-known to be a significant source of atmospheric methane. With the predicted stronger effect of global climate change on arctic terrestrial ecosystems compared to lower-latitudes, there is a special obligation to study the natural diversity and the range of possible feedback effects on global climate that could arise from Arctic tundra ecosystems. One of the prime candidates for such a feedback mechanism is a potential change in the emissions of methane. Long-term datasets on methane emissions from high arctic sites are almost non-existing but badly needed for analyses of controls on interannual and seasonal variations in emissions. To help fill this gap we initiated a measurement program in a productive high arctic fen in the Zackenberg valley, NE Greenland. Methane flux measurements have been carried out at the same location since 1997. Compared with the manual chamber measurements from the late 1990s, however, an automatic chambers system with laser off- axis integrated-cavity output spectroscopy analyzer, in place since 2005, dramatically increased the time resolution of more recent data. The latest data brought up some intriguing findings on seasonal variations in methane fluxes which will be presented and discussed.
American Geophysical Union, Fall Meeting 2008, 2008