Radiometrically determined skin temperature and scalar roughness to estimate surface heat flux. Part I: Parameterization of radiometric scalar roughness |
| |
| Authors: | Akihiro Kubota Michiaki Sugita |
| |
| Institution: | (1) College of Natural Sciences, University of Tsukuba, 305 Tsukuba, Ibaraki, Japan;(2) Environmental Research Center, University of Tsukuba, 305 Tsukuba, Ibaraki, Japan |
| |
| Abstract: | A series of experiments carried out in a pasture field during a growing season, allowed a radiometric determination of the scalar roughness for sensible heatz
oh,r
. The values ofz
oh,r
are shown to vary over the range of 10–1–10–7m both diurnally and seasonally, and an existing theoretical model for the estimation of scalar roughness for sensible heat is found to be inappropriate for the precise estimation ofz
oh,r
. To parameterizez
oh,r
better, a multiple regression analysis was performed, with predictor candidates such as solar elevation, solar radiationR
s
, leaf area index LAI, canopy height, the ratio of the solar radiation and the extraterrestrial radiationR
s
/R
e
, the ratio of the direct and the total solar radiationR
d
/R
s
, and the roughness Reynolds number among others. The best regression equation which usesR
s
, LAI,R
s
/R
e
, andR
d
/R
s
is derived withr=0.75; with smaller numbers of predictors, values ofr tend to deteriorate gradually down tor=0.52 when only one predictor, LAI, was incorporated into the equation. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
