干旱区生态环境知识资源中心(Arid): Energy balance closures in diverse ecosystems of an endorheic river basin

Arid

DOI	10.1016/j.agrformet.2019.04.019
	Energy balance closures in diverse ecosystems of an endorheic river basin
	Zhou, Yanzhao 1,2,3; Li, Xin1,4
通讯作者	Li, Xin
来源期刊	AGRICULTURAL AND FOREST METEOROLOGY
ISSN	0168-1923
EISSN	1873-2240
出版年	2019
卷号	274 页码:118-131
英文摘要	The surface energy imbalance or non-closure problem, where the sum of turbulent heat fluxes measured by the eddy covariance method is systematically lower than the available energy, is one of the greatest challenges in micrometeorology. We examine the energy balance closure ratio (EBR) and its relationship with related variables over a wide variety of ecosystems including alpine meadow, desert, shrub, and crops in the Heihe River Basin (HRB), China, which is representative of endorheic river basins. The results show that half-hour EBR values over different ecosystems range from 0.53 to 0.99, with a mean of 0.84. In different HRB ecosystems, the trends of EBR values with friction velocity (u()), thermally induced turbulence (TT), atmospheric stability (z/L), correlation coefficients for vertical velocity and water vapor (R-wq) and potential temperature (R-w theta), and relative vertical turbulent intensity (RI) are consistent with previous results obtained from other ecosystems. A significant negative linear relationship exists between the EBR and variation values of surface temperatures at landscape and local scales. Additionally, the field data confirm our previous findings from large eddy simulations that there is a positive linear relationship between the turbulent kinetic energy (TKE) and EBR values. Because the TKE diurnal variations explain a larger fraction (71%) of EBR diurnal variations than other variables (u(), TT, z/L, RI, R-w theta and R-wq), we argue that TKE is mainly responsible for EBR diurnal variations and explains the different EBR diurnal variations observed here and in previous studies. The possible reason for this better performance of TKE than other variables is that the TKE includes comprehensive effects of shear, buoyancy, turbulent transport and dissipation from the TKE budget equation. Thus, TKE may be a promising indicator for potential energy balance closure correction. Our findings contribute to a better understanding of the surface energy imbalance problem.
英文关键词	Surface energy non-closure problem Turbulent kinetic energy Diurnal variations Eddy covariance method Heihe River Basin
类型	Article
语种	英语
国家	Peoples R China
收录类别	SCI-E
WOS记录号	WOS:000471356600012
WOS关键词	EDDY-COVARIANCE ; SURFACE HETEROGENEITY ; EXPERIMENT EBEX-2000 ; IMBALANCE PROBLEM ; FLUX IMBALANCE ; FOREST ; EXCHANGE ; IMPACT ; MODEL ; EVAPOTRANSPIRATION
WOS类目	Agronomy ; Forestry ; Meteorology & Atmospheric Sciences
WOS研究方向	Agriculture ; Forestry ; Meteorology & Atmospheric Sciences
来源机构	中国科学院青藏高原研究所
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/213961
作者单位	1.Chinese Acad Sci, Inst Tibetan Plateau Res, Beijing 100010, Peoples R China; 2.Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, Key Lab Remote Sensing Gansu Prov, Lanzhou, Gansu, Peoples R China; 3.Univ Chinese Acad Sci, Beijing, Peoples R China; 4.Chinese Acad Sci, CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing, Peoples R China
推荐引用方式 GB/T 7714	Zhou, Yanzhao,Li, Xin. Energy balance closures in diverse ecosystems of an endorheic river basin[J]. 中国科学院青藏高原研究所,2019,274:118-131.
APA	Zhou, Yanzhao,&Li, Xin.(2019).Energy balance closures in diverse ecosystems of an endorheic river basin.AGRICULTURAL AND FOREST METEOROLOGY,274,118-131.
MLA	Zhou, Yanzhao,et al."Energy balance closures in diverse ecosystems of an endorheic river basin".AGRICULTURAL AND FOREST METEOROLOGY 274(2019):118-131.