Abstracts for the 5th International GAME Conf.

3-5 October 2001

Aichi Trade Center

Nagoya Japan

Simulated rainfall in a GCM with retrieved root-zone soil moisture from surface soil moisture estimated with TRMM/PR over the Tropics

Yukiko Hirabayashi (1), Shinta Seto (1), Shinjiro Kanae (1), Taikan Oki (1), Katumi Musiake (1)

The purpose of the present study is an application of satellite-based soil moisture to numerical climate simulation. The research consists of two parts. First, a method of estimating root-zone soil moisture from surface soil moisture has developed with use of JMA/SiB GSWP soil moisture data. Comparisons of surface and root-zone soil moisture of JMA/SiB global GSWP data indicate that the shapes of time variation of surface and root-zone soil moisture look similar and there exists time lag between them. It is also found that the correlation functions of surface and root-zone soil moisture become liner after shifting the variation times of root-zone soil moisture to fit those of surface. With the use of this empirical regression line, root-zone soil moisture can be estimated from surface soil moisture. This method is applied to the satellite-based surface soil moisture estimated with TRMM/PR microwave remote sensing. Second, simulated seasonal rainfall (June-August) over the tropics with CCSR/NIES AGCM are compared with observations in terms of different boundary soil moistures. Numerical results show that precipitation error in the model is larger comparing to a simulation with climatological soil moisture when soil moisture estimated with TRMM/PR satellite in the Tropics is directly applied to the model as if this value is representative of the deeper soil moisture. The precipitation error is decreased when the converted soil moisture from satellite data with our method is applied in stead of the direct use of satellite observations. It is also shown from the result that the precipitation error of this simulation is less than the simulation with climatological soil in the tropics, where satellite-based soil moisture is applied to the model.

Submittal Information

Name : Date :
    Yukiko Hirabayashi
    31-May-01-13:21:33
Organization : Theme :
    IIS, University of Tokyo
    Theme 3
Address : Presentation :
    Musiake labo., 4-6-1, Komaba, Meguro-ku, Tokyo
    Only poster
Country : Abstract ID :
    Japan
    T3YH31May01132133
Phone : Fax :
    +81-3-5452-6381
    +81-3-5452-6383
E-mail :
    yukko@iis.u-tokyo.ac.jp