Estimation of precipitation in the Tibetan Plateau by using TRMM/TMI data based on surface emissivity consideration
Hideyuki Fujii (1), Toshio Koike (2)
(1) Japan Science and Technology Corporation
(2) Department of Civil Engineering, University of Tokyo
This paper proposes a new algorithm for precipitation over land by deriving the optical thickness from the brightness temperature of the Tropical Rainfall Measuring Mission (TRMM) Microwave Imager (TMI). The effect of land surface controlled by soil moisture emissivity on radiation transfer is taken into account in this algorithm. This means that soil moisture can be estimated at the same time in addition to precipitation. Based on a microwave radiative transfer equation, two indices, Index of Soil Wetness (ISW) and Polarization Index (PI), which remove the effect of land surface physical temperature, are introduced into the algorithm.
The application of the algorithm to the GAME-Tibet meso-scale experimental field shows a good agreement with the spatial patterns of precipitation observed by the 3D Doppler radar. The estimated soil moisture shows good correspondence with the observed one. A reasonable relationship between the estimated optical thickness, and observed precipitation by rain gauges, is obtained after 10 days of longer temporal averaging.
Submittal Information
Name :
Date :
Hideyuki Fujii
02-Jun-01-11:02:39
Organization :
Theme :
Japan Science and Technology Corporation
Theme 4
Address :
Presentation :
Department of Civil Engineering, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
