Abstracts for the 5th International GAME Conf.

3-5 October 2001

Aichi Trade Center

Nagoya Japan

Estimation of parameter on canopy conductance model based on turbulent flux observation

Izumi KOSAKA (1), Hideki TAKIZAWA (1), Katsunori TANAKA (3), Masakazu SUZUKI (4), Chatchai TANTASIRIN (5), Nipon TANGTHAM (5)

We estimated parameter of canopy conductance (gc) model on big-leaf model based on turbulent flux observation in the hill evergreen forest that a lot of gaps exist, and the average of tree height is about 30m. Turbulent flux observation had been carried out for several days with an ultrasonic anemometer (Kaijo DA-600) and an infrared gas analyzer (Li-6262) set up at 39m using the 50m meteorological tower in the Kog-Ma experimental watershed of GAME/Tropics, and sensible heat flux (H) and latent heat flux (lE) calculated by eddy correlation method. As a result, the average ratio of observed (H+lE) to net radiation (Rn) was about 0.6. In a word, the imbalance was caused this experiment. However,the ratio of (H+ lE) to Rn had the lower bound value of about 0.4. Then, we divided the ratio of (H+ lE) which contained the imbalance to Rn, as follows MethodT:ratio0.4, MethodU:ratio0.6, Rn-H . The parameter of gc model was estimated using lE selected by the above-mentioned four methods. The fitting data was decreased as the ratio increased. So, in order to verify the validity of gc model parameter that estimated four methods, we simulated annual lE and H with big-leaf model. Results showed that the simulated lE was 800mm/yr from MethodT, 1000mm/yr from MethodU, 1100mm/yr from MethodV, and 1300mm/yr from MethodW(Rn was 1300mm/yr in this period). It showed that the simulated lE was gradually increased from MethodT to MethodW.

Submittal Information

Name : Date :
    Izumi KOSAKA
    10-Jun-01-09:52:06
Organization : Theme :
    Graduate School of Bioresource sciences
    Theme 1
Address : Presentation :
    1866 Kameino, Fujisawa, Kanagawa 252-0813
    Poster or oral
Country : Abstract ID :
    Japan
    T1IK10Jun01095206
Phone : Fax :
    0466-84-3764
    0466-80-1135
E-mail :
    98fsr057@brs.nihon-u.ac.jp