气候变化领域集成服务门户(CCPortal): Diurnal Variations of the Flux Imbalance Over Homogeneous and Heterogeneous Landscapes

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DOI	10.1007/s10546-018-0358-2
	Diurnal Variations of the Flux Imbalance Over Homogeneous and Heterogeneous Landscapes
	Zhou, Yanzhao; Li, Dan; Liu, Heping; Li, Xin
通讯作者	Li, X (通讯作者)
发表日期	2018
ISSN	0006-8314
EISSN	1573-1472
起始页码	417
结束页码	442
卷号	168 期号:3
英文摘要	It is well known that the sum of the turbulent sensible and latent heat fluxes as measured by the eddy-covariance method is systematically lower than the available energy (i.e., the net radiation minus the ground heat flux). We examine the separate and joint effects of diurnal and spatial variations of surface temperature on this flux imbalance in a dry convective boundary layer using the Weather Research and Forecasting model. Results show that, over homogeneous surfaces, the flux due to turbulent-organized structures is responsible for the imbalance, whereas over heterogeneous surfaces, the flux due to mesoscale or secondary circulations is the main contributor to the imbalance. Over homogeneous surfaces, the flux imbalance in free convective conditions exhibits a clear diurnal cycle, showing that the flux-imbalance magnitude slowly decreases during the morning period and rapidly increases during the afternoon period. However, in shear convective conditions, the flux-imbalance magnitude is much smaller, but slightly increases with time. The flux imbalance over heterogeneous surfaces exhibits a diurnal cycle under both free and shear convective conditions, which is similar to that over homogeneous surfaces in free convective conditions, and is also consistent with the general trend in the global observations. The rapid increase in the flux-imbalance magnitude during the afternoon period is mainly caused by the afternoon decay of the turbulent kinetic energy (TKE). Interestingly, over heterogeneous surfaces, the flux imbalance is linearly related to the TKE and the difference between the potential temperature and surface temperature, Delta T; the larger the TKE and Delta T values, the smaller the flux-imbalance magnitude.
关键词	ENERGY-BALANCE CLOSURE LARGE-EDDY SIMULATION CONVECTIVE TURBULENCE BOUNDARY-LAYER TOWER MEASUREMENTS COVARIANCE FLUXES LAND-SURFACE PART I MODEL DECAY
英文关键词	Convective boundary layer; Diurnal variations; Flux imbalance; Large-eddy simulation; Spatial heterogeneity
语种	英语
WOS研究方向	Meteorology & Atmospheric Sciences
WOS类目	Meteorology & Atmospheric Sciences
WOS记录号	WOS:000440422100003
来源期刊	BOUNDARY-LAYER METEOROLOGY
来源机构	中国科学院青藏高原研究所
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/259238
推荐引用方式 GB/T 7714	Zhou, Yanzhao,Li, Dan,Liu, Heping,et al. Diurnal Variations of the Flux Imbalance Over Homogeneous and Heterogeneous Landscapes[J]. 中国科学院青藏高原研究所,2018,168(3).
APA	Zhou, Yanzhao,Li, Dan,Liu, Heping,&Li, Xin.(2018).Diurnal Variations of the Flux Imbalance Over Homogeneous and Heterogeneous Landscapes.BOUNDARY-LAYER METEOROLOGY,168(3).
MLA	Zhou, Yanzhao,et al."Diurnal Variations of the Flux Imbalance Over Homogeneous and Heterogeneous Landscapes".BOUNDARY-LAYER METEOROLOGY 168.3(2018).