Case Analyses and Numerical Simulation of Soil ThermalImpacts on Land Surface Energy Budget Based on anOff-Line Land Surface Model  

土壤热异常影响地表能量平衡的个例分析和数值模拟(英文)

作　　者：郭维栋 孙菽芬 钱永甫 

机构地区：[1]Department of Atmospheric Sciences Nanjing University, Nanjing 210093,LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029 [2]LASG, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029 [3]Department of Atmospheric Sciences Nanjing University,Nanjing,210093

出　　处：《Advances in Atmospheric Sciences》2002年第3期500-512,共13页大气科学进展（英文版）

基　　金：This paper is jointly sponsored by China NKBRSF Project G1999043400,National Natural Science Foundationof China under Grant Nos.49835010and 40075019,and China Post Doctoral Science Foundation.

摘　　要：The statistical relationship between soil thermal anomaly and short-term climate change is presented based on a typical case study. Furthermore, possible physical mechanisms behind the relationship are re-vealed through using an off-line land surface model with a reasonable soil thermal forcing at the bottom of the soil layer. In the first experiment, the given heat flux is 5 W m<SUP>2</SUP> at the bottom of the soil layer (in depth of 6.3 m) for 3 months, while only a positive ground temperature anomaly of 0.06°C can be found compared to the control run. The anomaly, however, could reach 0.65°C if the soil thermal conductivity was one order of magnitude larger. It could be even as large as 0.81°C assuming the heat flux at bottom is 10 W m<SUP>-2</SUP>. Mean-while, an increase of about 10 W m<SUP>&#8722;2</SUP> was detected both for heat flux in soil and sensible heat on land sur-face, which is not neglectable to the short-term climate change. The results show that considerable response in land surface energy budget could be expected when the soil thermal forcing reaches a certain spatial-tem-poral scale. Therefore, land surface models should not ignore the upward heat flux from the bottom of the soil layer. Moreover, integration for a longer period of time and coupled land-atmosphere model are also necessary for the better understanding of this issue.The statistical relationship between soil thermal anomaly and short-term climate change is presented based on a typical case study. Furthermore, possible physical mechanisms behind the relationship are re-vealed through using an off-line land surface model with a reasonable soil thermal forcing at the bottom of the soil layer. In the first experiment, the given heat flux is 5 W m<SUP>2</SUP> at the bottom of the soil layer (in depth of 6.3 m) for 3 months, while only a positive ground temperature anomaly of 0.06°C can be found compared to the control run. The anomaly, however, could reach 0.65°C if the soil thermal conductivity was one order of magnitude larger. It could be even as large as 0.81°C assuming the heat flux at bottom is 10 W m<SUP>-2</SUP>. Mean-while, an increase of about 10 W m<SUP>&#8722;2</SUP> was detected both for heat flux in soil and sensible heat on land sur-face, which is not neglectable to the short-term climate change. The results show that considerable response in land surface energy budget could be expected when the soil thermal forcing reaches a certain spatial-tem-poral scale. Therefore, land surface models should not ignore the upward heat flux from the bottom of the soil layer. Moreover, integration for a longer period of time and coupled land-atmosphere model are also necessary for the better understanding of this issue.

关 键 词：Soil thermal anomaly Land surface model Land surface energy budget 

分 类 号：P435[天文地球—大气科学及气象学]