The Sensitivity of Ground Surface Temperature Prediction to Soil Thermal Properties Using the Simple Biosphere Model(SiB2)  

作　　者：张晓惠 高志球 魏东平 

机构地区：[1]College of Earth Science,Graduate University of Chinese Academy of Sciences [2]Key Laboratory of Computational Geodynamics,Chinese Academy of Sciences [3]State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics,Chinese Academy of Sciences [4]College of Applied Meteorology,Nanjing University of Information Science and Technology

出　　处：《Advances in Atmospheric Sciences》2012年第3期623-634,共12页大气科学进展（英文版）

基　　金：supported by National Natural Science Foundation of China (Grant No.40874047);supported by National Natural Science Foundation of China (Grant No.40975009);supported by the National Key Basic Research Program (Grant No. 2012CB417203)

摘　　要：Using the Simple Biosphere Model （SiB2）, soil thermal properties （STP） were examined in a Tibetan prairie during the monsoon period to investigate ground surface temperature prediction. We improved the SiB2 model by incorporating a revised force-restore method （FRM） to take the vertical heterogeneity of soil thermal diffusivity （k） into account. The results indicate that （1） the revised FRM alleviates daytime overestimation and nighttime underestimation in modeled ground surface temperature （Tg）, and （2） its role in little rainfall events is significant because the vertical gradient of k increases with increasing surface evaporation. Since the original formula of thermal conductivity （A） in the SiB2 greatly underestimates soil thermal conductivity, we compared five Mgorithms of A involving soil moisture to investigate the cause of overestimation during the day and underestimation at night on the basis of the revised FRM. The results show that （1） the five algorithms significantly improve Tg prediction, especially in daytime, and （2） taking one of these five algorithms as an example, the simulated Tg values in the daytime are closer to the field measurements than those in the nighttime. The differences between modeled Tg and field measurements are mostly within the margin of error of -4-2 K during 3 August to 4 September 1998.Using the Simple Biosphere Model （SiB2）, soil thermal properties （STP） were examined in a Tibetan prairie during the monsoon period to investigate ground surface temperature prediction. We improved the SiB2 model by incorporating a revised force-restore method （FRM） to take the vertical heterogeneity of soil thermal diffusivity （k） into account. The results indicate that （1） the revised FRM alleviates daytime overestimation and nighttime underestimation in modeled ground surface temperature （Tg）, and （2） its role in little rainfall events is significant because the vertical gradient of k increases with increasing surface evaporation. Since the original formula of thermal conductivity （A） in the SiB2 greatly underestimates soil thermal conductivity, we compared five Mgorithms of A involving soil moisture to investigate the cause of overestimation during the day and underestimation at night on the basis of the revised FRM. The results show that （1） the five algorithms significantly improve Tg prediction, especially in daytime, and （2） taking one of these five algorithms as an example, the simulated Tg values in the daytime are closer to the field measurements than those in the nighttime. The differences between modeled Tg and field measurements are mostly within the margin of error of -4-2 K during 3 August to 4 September 1998.

关 键 词：land surface processes SIB2 sensitivity ground surface temperature soil thermal diffusivity soil thermal conductivity 

分 类 号：P423[天文地球—大气科学及气象学]