HR: 1340h
AN: B43B-0159    [Abstracts]
TI: Seasonal and Inter-annual Variations of Methane Flux at Wet Tundra in North Slope, Alaska
AU: * Harazono, Y
EM: y.harazono@uaf.edu
AF: International Arctic Research Center, University of Alaska Fairbanks, 930 Koyukuk Dr., Fairbanks, AK 99775 United States
AU: Mano, M
EM: mmano@niaes.affrc.go.jp
AF: National Institute for Agro-Environmental Sciences, Kannondai 3-1-3, Tsukuna, 305-8604 Japan
AU: Miyata, A
EM: amiyat@niaes.affrc.go.jp
AF: National Institute for Agro-Environmental Sciences, Kannondai 3-1-3, Tsukuna, 305-8604 Japan
AU: Yoshimoto, M
EM: yosjimot@niaes.affrc.go.jp
AF: National Institute for Agro-Environmental Sciences, Kannondai 3-1-3, Tsukuna, 305-8604 Japan
AU: Zulueta, R C
EM: zulueta@mail.sdsu.edu
AF: Global Change Research Group, San Diego State University, 5500 Campanile Drive, PS247, San Diego, CA 92182 United States
AU: Kwon, H
EM: hkwon@sciences.sdsu.edu
AF: Global Change Research Group, San Diego State University, 5500 Campanile Drive, PS247, San Diego, CA 92182 United States
AU: Oechel, W C
EM: oechel@sunstroke.sdsu.edu
AF: Global Change Research Group, San Diego State University, 5500 Campanile Drive, PS247, San Diego, CA 92182 United States
AB: Methane (CH4) is a very effective greenhouse gas, and its major source in nature is anaerobic ecosystem. As high latitude ecosystems such as tundra and wetland pool large amount of organic carbon in the soil layer, which may enhance the CH4 emission in relation to the current arctic warming. However, we have a little information of potential feedback mechanisms on climate change and greenhouse gas emission, thus model parameterization of CH4 emission is insufficient and the future estimation includes large uncertainties. We have measured CH4 flux at inland wet tundra (Happy Valley) in 1995 & 96 and at coastal tundra (Barrow) from 1999. We applied aerodynamic method to determine CH4 flux, which provides continuous flux as hectare scale under natural condition. CO2 and energy fluxes were measured by eddy correlation method. Hourly CH4 flux showed unclear daily variation with soil temperature nor solar radiation but the daily flux levels (seasonal trend) changed with seasonal change of soil temperature at 10-cm depth. Seasonal cumulative CH4 flux at inland wet tundra at happy valley was 8.1 gCH4m-2 in 1995 and that at moist tundra (non-acidic) was 3.3 gCH4m-2 in 1996 growing season. At Barrow, CH4 flux increased rapidly after snowmelt and the peak flux occurred in mid July with yearly different levels 60-120mgCH4m-2d-1. Cumulative CH4 flux during the growing period varied 4.2-6.6 gCH4m-2 from 1999-2003. The carbon ratio of emitted CH4 to the NEP of the vegetation was around 3% over the measured period.
DE: 1851 Plant ecology
DE: 1600 GLOBAL CHANGE (New category)
DE: 0312 Air/sea constituent fluxes (3339, 4504)
DE: 0315 Biosphere/atmosphere interactions
DE: 0400 Biogeosciences
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting