HR: 0800h
AN: C41A-0177    [Abstracts]
TI: Wind directional dependency of surface energy fluxes over north-eastern Siberia and its implications
AU: * Kodama, Y
EM: kod@pop.lowtem.hokudai.ac.jp
AF: Institute of Low Temperature Science, Hokkaido University, N-19, W-8, Kita, Sapporo, 060-0819 Japan
AU: Sato, N
EM: msat@pop.lowtem.hokudai.ac.jp
AF: Institute of Low Temperature Science, Hokkaido University, N-19, W-8, Kita, Sapporo, 060-0819 Japan
AU: Yabuki, H
EM: yabuki@jamstec.go.jp
AF: Institute of Observational Research for Global Change, JAMSTEC, 3173-25 Showa, Kanazawa, Yokohama, 236-0001 Japan
AU: Ishii, Y
EM: ishiiy@pop.lowtem.hokudai.ac.jp
AF: Institute of Low Temperature Science, Hokkaido University, N-19, W-8, Kita, Sapporo, 060-0819 Japan
AU: Nomura, M
EM: nomu@exfor.agr.hokudai.ac.jp
AF: Field Science Ceter for Northern Biosphere, Hokkaido University, Toikanbetsu, Horonobe, 098-2943 Japan
AU: Ohata, T
EM: ohata@pop.lowtem.hokudai.ac.jp
AF: Institute of Low Temperature Science, Hokkaido University, N-19, W-8, Kita, Sapporo, 060-0819 Japan
AB: In order to better understand the water cycle over tundra, micro-meteorlogical and hydrological observations were carried out over tundra near Tiksi, North-eastern Siberia and seasonal variations of energy budget components were estimated for two years. As an average, net radiation was partitioned for sensible heat flux 25-30%, for latent heat flux 50-55% and for soil conductive heat flux 20%. Those ratios were changed by wind direction. The southwesterly winds were warm and dry, made the sensibe heat flux small or its direction changed to ground surface, and the northeasterly winds were cold, gave the sensible heat flux to the atmosphere from the tundra surface. The southwesterly winds were associated with cyclone intrusions to this area and the northeasterly winds with anti-cyclones. More frequent intrusions of cyclones would decrease the sensible heat flux and increase the latent heat flux. A simple air temperature increase experiments using a simple heat balance model showed the sensible heat flux unchanged and the latent heat flux and conducetive heat flux in soil increased.
DE: 3322 Land/atmosphere interactions
DE: 1655 Water cycles (1836)
SC: Cryosphere [C]
MN: 2004 AGU Fall Meeting