Methane loss from Arctic: towards an annual budget of CH4 emissions from tundra ecosystems across a latitudinal gradient

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The research project will investigate year-around CH4 and CO2 fluxes at three Alaskan Arctic sites (Barrow, Aquasuk, and Ivotuk) across a latitudinal gradient of about 300 Km from the northern part of the Arctic Coastal Plain to the foothills of the Brooks Range, in Alaska. These measurements will be used to improve estimates of rates and patterns of and controls on annual GHG fluxes, with special contribution to understanding of the fall, winter and spring fluxes. This project will be among the first efforts toward the estimation of a full annual budget of both CH4 and CO2 net emissions from three tundra ecosystems across a transect in Arctic Alaska. Of primary importance is the quantification of non-summertime CH4 emissions because of the potentially large impact on overall climatic effects. This information has historically been very difficult to collect because of severe weather and remote monitoring stations. Recent advances in measurement technology will make these studies feasible in remote locations and under extreme weather conditions. In particular, this research will make use of the new closed-path LI-7200 and the self-cleaning and heated, low-power,open-path LI-7700 CH4 analyzer for the most remote site (Ivotuk). The team will employ the closed-path CH4 Los Gatos analyzer that corrects for the cross-sensitivity of water for the Barrow and Atqasuk sites. A heated sonic Class-A METEK will be used to record turbulence measurements. In-situ measurements of oxidation-reduction potential, pH, dissolved gases, chemical characterization of soils and soil pore water, and metagenomic analysis will elucidate the dominant respiratory pathways. Project scientists and SDSU will partner with the Reuben H. Fleet Science Centre to improve polar and climate change knowledge and understanding. Project activities will include workshops and seminars on climate change, and potential GHG feedbacks in the Arctic for teachers and the general public in the San Diego area, and for the community in Barrow.