干旱区生态环境知识资源中心(Arid): 干旱区不同下垫面能量分配机理及对微气候反馈的研究

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	干旱区不同下垫面能量分配机理及对微气候反馈的研究
其他题名	Study of energy partitioning and its feedback on the microclimate over different surfaces in an arid zone
	李宏宇 1; 符淙斌 1; 郭维栋 1; 马芳 2
来源期刊	物理学报
ISSN	1000-3290
出版年	2015
卷号	64 期号:5 页码:059201-1-059201-14
中文摘要	本文利用位于美国新墨西哥州距离接近并且天气背景相同的四种下垫面(沙漠草原、稀疏灌木林、稀树草原和浓密灌木林)站点的通量观测资料, 探讨了几种典型干旱下垫面的能量分配差异, 并分析了其对微气候的反馈机理. 结果表明, 四种下垫面叶面积指数和粗糙度在由沙漠草原指向浓密灌木林的梯度方向上呈现增加的趋势, 低覆盖度下垫面表现出更强的湍流输送阻力. 总体来看, 高覆盖度下垫面的净辐射、感热和潜热相对更高, 尤其在生长季更明显.利用Penman-Monteith公式以及净辐射结合波文比两种方法诊断了在不同下垫面更替中湍流通量各影响因子的贡献. 随着植被覆盖程度的提高, 净辐射的变化对感热和潜热的变化起着决定作用, 且为正贡献; 地表阻抗和空气动力学阻抗变化引起的贡献相反. 此外, 沙漠草原和稀疏灌木林的地表温度和气温均高于浓密灌木林, 主要源于稀疏植被增大的空气动力学阻抗和波文比引起的增温贡献, 同时抵消了净辐射减小引起的降温效应, 表明在相同气候和天气背景下, 不同下垫面的陆面过程确实会对近地层微气候有明显的反馈作用.
英文摘要	Model simulations show that land use and land cover changes(LUCC) may alter surface energy budget and influence surface microclimate, but up to now, it still lacks of sufficient observations for explaining the mechanism of climate change brought about by LUCC. Grasslands and shrub lands are typical land covers in the mid-latitude arid zone of the northern hemisphere. The data used in this paper was collected from four sites which are related to grassland, open shrubland, savanna and closed shrubland, and all located in New Mexico, USA. The four sites are near each other and have the same background in climate and weather. Thus, the difference in surface energy partitioning over the four surfaces is induced by different land processes, which was explained in our study. The paper also analyzed the feedbacks of different land surface parameters and energy partitioning for the surface microclimate.We find that the leaf area index(LAI) and surface roughness of the four sites increases from the desert grassland to the closed shrubland. The difference in vegetation structures and functions also affects aerodynamic resistance and surface resistance to heat transfer and the resistances exhibit larger over sparse surfaces. Generally, the sites with high vegetation cover have higher net radiation, sensible and latent heat fluxes, particularly in the growing season. In addition, the contributions of impacting factors to the turbulent fluxes are diagnosed by Penman-Monteith equation and a mathematical formula combining net radiation with Bowen ratio. Compared to the desert grassland, the variations in net radiation over other three surfaces indicate positive contributions to both sensible and latent heat fluxes and govern their changes. The variations in the aerodynamic resistance and the surface resistance lead to opposite contributions. Besides, both radiative surface temperature and surface air temperature over the sparse surfaces are significantly higher than that over the closed shrubland. Larger aerodynamic resistance and Bowen ratio over the sparse vegetation dominate the warming trend accompanying the vegetation degradation and simultaneously offset the cooling effect induced by the decrease in net radiation, showing the land surface process over different surfaces factually has an evident feedback on surface micro-climate in the same climate and weather background.
中文关键词	不同下垫面 ; 能量分配 ; 微气候 ; 反馈作用
英文关键词	Different surfaces energy partitioning microclimate feedback
语种	中文
国家	中国
收录类别	CSCD
WOS类目	PHYSICS MULTIDISCIPLINARY
WOS研究方向	Physics
CSCD记录号	CSCD:5375958
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/233460
作者单位	1.南京大学大气科学学院, 气候与全球变化研究院, 南京, 江苏 210093, 中国; 2.国家发展和改革委员会国际合作中心规划设计研究院, 环境研究所, 北京 100045, 中国
推荐引用方式 GB/T 7714	李宏宇,符淙斌,郭维栋,等. 干旱区不同下垫面能量分配机理及对微气候反馈的研究[J],2015,64(5):059201-1-059201-14.
APA	李宏宇,符淙斌,郭维栋,&马芳.(2015).干旱区不同下垫面能量分配机理及对微气候反馈的研究.物理学报,64(5),059201-1-059201-14.
MLA	李宏宇,et al."干旱区不同下垫面能量分配机理及对微气候反馈的研究".物理学报 64.5(2015):059201-1-059201-14.