2008年夏季中国干旱-半干旱区陆面主要物理参数的平均特征  

Mean Characteristics of Land Surface Key Parameters in Semi-Arid and Arid Regions of China in Summer of 2008

作　　者：曾剑[1,2] 张强[1,3] 

机构地区：[1]中国气象局兰州干旱气象研究所/甘肃省干旱气候变化与减灾重点试验室/中国气象局干旱气候变化与减灾重点开放实验室,甘肃兰州730020 [2]北京市气象台,北京100089 [3]甘肃省气象局,甘肃兰州730020

出　　处：《高原气象》2012年第6期1539-1550,共12页Plateau Meteorology

基　　金：国家自然科学基金重点项目(40830597);国家公益性行业科研专项(GYHY200806021)共同资助

摘　　要：采用2008年7-9月观测的中国干旱-半干旱区试验观测协同与集成研究资料,选取12个测站(涵盖不同气候环境区的草地、农田、果林和森林等下垫面)比较分析了干旱-半干旱区的动力、热力和水汽粗糙度长度、总体输送系数、反照率以及土壤热传导率和热扩散率的夏季平均特征,并与陆面模式的理论参考值进行了对比。结果表明,植被下垫面的水、热特性和植被高度对主要陆面参数有重要影响,但植被下垫面的土壤热传导率和扩散率与下垫面类型之间无明显关系。动力学粗糙度长度与下垫面的植被高度呈正相关关系,无论是稳定还是不稳定层结下,动量拖曳系数都随着植被高度的增大而增大,而反照率随植被高度的增加而降低。在研究区的下垫面中,草地下垫面动力学粗糙度长度的实测值比模式理论参考值偏小,但农田和果林下垫面的实测值比理论参考值偏大;草地下垫面动量拖曳系数理论的参考值比实测值高,但其他下垫面的实测值高于理论参考值;实测反照率处于可见光反照率和近红外光反照率之间,但反照率的理论参考值比实测值偏高。By picking 12stations whose underlying land surfaces include grassland,cropland,orchard and forest,the climatic characteristics of land surface key parameters are investigated using the data measured from July to September 2008,provided the Northern China Observation Coordination and Integration Research in Semiarid and Arid Regions.The roughness lengths for momentum,sensible heat and water vapor,and bulk transfer coefficient,albedo,and soil thermal conductivity and diffusivity are calculated and compared within various underlying land surfaces.The results are compared with the model theoretic reference values as well.It shows that the thermal-hydrologic properties of vegetated land surface and vegetation height significantly influence some key land surface parameters,and that there is no evident relations between soil thermal conductivity and diffusivity and underlying surface types.Specifically aerodynamic roughness length and momentum drag coefficient increase with increasing vegetation height,but albedo decreases with vegetation height.The measured aerodynamic roughness length of grassland is smaller than model reference value,but it is not true for cropland and orchard.The measured momentum drag coefficient is larger than model reference value over grassland,but it is smaller than model reference value in other underlying surfaces.The measured albedo is basically lower than its model reference value although it lies between visible albedo and near-infrared albedo.

关 键 词：中国干旱-半干旱区 不同下垫面 陆面参数 气候特征 

分 类 号：P404[天文地球—大气科学及气象学]