HR: 15:10h
AN: B52D-06    [PDF]
TI: Annual CO2 budget at arctic wet sedge tundra in Barrow and the contribution of winter fluxes
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, 3-3-1 Kannondai, Tsukuba, 305-8406 Japan
AU: Miyata, A
EM: amiyat@niaes.affrc.go.jp
AF: National Institute for Agro-Environmental Sciences, 3-3-1 Kannondai, Tsukuba, 305-8406 Japan
AU: Kwon, H
EM: hkwon@sciences.sdsu.edu
AF: Global Change Research Group, San Diego State University, San Diego, San Diego, CA 92182 United States
AU: Oechel, W C
EM: oechel@sunstroke.sdsu.edu
AF: Global Change Research Group, San Diego State University, San Diego, San Diego, CA 92182 United States
AB: Although the longer winter period in the arctic affects annual CO2 budget, there have been few direct flux observations because of the sever climate. We measured CO2 and energy fluxes by eddy correlation technique and the micrometeorology at wet sedge tundra in Barrow, Alaska from 1999 spring. The data obtained continuously provided huge upward fluxes during snow-covered period, which occurred during blizzard events. The measured upward fluxes during the strongest blizzard event in mid winter showed CO2 source of 198 g CO2 m-2, 12 MJ/ m-2 and16 MJ/ m-2 for sensible and latent heat fluxes. If the fluxes were facts, which might be large contributions on annual carbon and energy budgets. We analyzed the fluxes and the micrometeorology detailed and revealed that the upward fluxes in mid-winter resulted in sublimation during blizzard, thus the huge upward fluxes in winter were thought to be apparent, especially CO2 efflux was thought to be unpractical flux converted from carbonic acid in the snow. Average winter respiration between 1999-2002 (upward CO2 flux during October to May) was around 55 gC m-2 which was almost the same as ecosystem respiration during the growing period (June-September). The annual CO2 budget was sink of 16-102 gC m-2, in which the large deviation among three years resulted in different CO2 sink levels in growing periods caused by different climate in each year.
DE: 0400 Biogeosciences
DE: 1600 GLOBAL CHANGE (New category)
DE: 1630 Impact phenomena
DE: 1827 Glaciology (1863)
DE: 1878 Water/energy interactions
SC: Biogeosciences [B]
MN: 2003 Fall Meeting