Methane Flux Data, Alaska North Slope, 1994-1995 William Reeburgh, University of California, Irvine During the summers from 1994 to 1996, methane fluxes were collected at Happy Valley and Toolik Lake ARCSS/LAII study sites. Air and soil temperatures were also collected in conjunction with the methane measurements. The data were collected at varied times during the field season, from every other day to weekly. Water table manipulations were also done to determine the sensitivity of the wet tundra methane and carbon dioxide fluxes to changes in the water table. The goals of the methane component of the Arctic System Science (ARCSS) Land/Air/Ice Interactions (LAII) Flux Study were to (1) produce regional methane flux estimates and (2) perform field experiments that would elucidate the controls and feedback's on methane and carbon dioxide emission from tundra environments. The regional flux estimates were be made using time series chamber measurements at permanent sites in a range of physiographic provinces. The site locations and times of measurement were coordinated with other project components. "The field experiments involved manipulations of soil water table level, as well as jar and " core experiments. Collections for stable carbon/hydrogen isotope and natural radiocarbon of emitted and source methane were made. The experiments provided information on the "relationship of methane oxidation to water table level and moisture changes, and the role of oxidation" and recently-fixed carbon in methane and carbon dioxide emissions. The goals of the water table manipulation experiments were aimed at determining the sensitivity of wet tundra methane and carbon dioxide fluxes to changes in water table. "The objectives were to (1) design, build and test and experimental pumping system suitable for "performing water table manipulation experiments on meter-scale sites, and (2) to employ" this system in well- understood wetland sites to determine the sensitivity of methane and carbon dioxide emissions in natural systems to changes in water table level. The data files are in two different formats, ascii and Excel, and the names reflect the site locations and the water table data. Happy Valley data are in hpyvally.dat and hpyvally.xls. Toolik Lake data are in tooliklk.dat and tooliklk.xls. The water table data are in watrtab.dat and watrtab.xls.