Abstracts for the 5th International GAME Conf.

3-5 October 2001

Aichi Trade Center

Nagoya Japan

Characteristics of Surface Fluxes Observed over Tundra in Eastern Siberia

Yuji Kodama (1), Norifumi Sato (1), Hironori Yabuki (3), Yoshiyuki Ishii (1), Mutsumi Nomura (5), Tetsuo Ohata (1)

Tundra area has a unique water cycle due to the existence of frozen ground, drifting snow and tundra vegetation. In order to better understand the water cycle over tundra, micro-meteorological and hydrological observations have been carried out near Tiksi, Eastern Siberia. A 10m meteorological mast was erected and air temperature, humidity, wind speed and direction were measured at the different height from the ground. Concurrently carried out was the observations of 4 radiation components, soil temperatures and moistures, barometric pressure and precipitation. The heat budget equation at the tundra surface was solved approximating the surface temperature by iteration. In the equation, sensible and latent heat fluxes were expressed by a bulk method and the soil heat flux by the gradient method. The bulk coefficient was a function of the bulk Richardson number and the evaporation efficiency and the thermal conductivity of the surface soil was a function of surface soil moisture. The result was obtained for 1998 and 1999, and well compared with result of Bowen ratio method, but not with the eddy correlation method. The seasonal change of heat balance components was also dependent on the atmospheric conditions. In this watershed, where locates 7 km from the Laptev Sea of the Arctic Ocean, the southwesterly wind was warm and dry, gave the sensible heat flux towards the ground surface and the northeasterly wind was cold and damp, gave the large sensible heat flux to the atmosphere from the tundra surface. The energy fluxes as well as the water fluxes were strongly dependent on the wind direction.

Submittal Information

Name : Date :
    Yuji Kodama
    16-May-01-15:56:51
Organization : Theme :
    Institute of Low Temperature Science, Hokkaido University
    Theme 2
Address : Presentation :
    Nishi 8, kita 19, Kitaku, Sapporo
    Poster or oral
Country : Abstract ID :
    Japan
    T2YK16May01155651
Phone : Fax :
    +81-11-706-5509
    +81-11-706-5509
E-mail :
    kod@pop.lowtem.hokudai.ac.jp