DOI: 10.5194/hess-21-3401-2017
Scopus记录号: 2-s2.0-85022191177
论文题名: Analysing surface energy balance closure and partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger National Park, South Africa
作者: Majozi N ; P ; , Mannaerts C ; M ; , Ramoelo A ; , Mathieu R ; , Nickless A ; , Verhoef W
刊名: Hydrology and Earth System Sciences
ISSN: 10275606
出版年: 2017
卷: 21, 期: 7 起始页码: 3401
结束页码: 3415
语种: 英语
Scopus关键词: Budget control
; Climate change
; Drought
; Energy balance
; Friction
; Interfacial energy
; Latent heat
; Calibration and validations
; Climate change impact
; Eddy covariance data
; Environmental Monitoring
; Ordinary least squares regressions
; Satellite based Earth observation
; Vapour pressure deficits
; Wet and dry seasons
; Heat flux
; climate change
; closure
; communication network
; eddy covariance
; energy balance
; environmental monitoring
; EOS
; evapotranspiration
; flux measurement
; land surface
; latent heat flux
; net radiation
; satellite imagery
; savanna
; semiarid region
; sensible heat flux
; site investigation
; surface energy
; vegetation cover
; Kruger National Park
; South Africa
英文摘要: Flux towers provide essential terrestrial climate, water, and radiation budget information needed for environmental monitoring and evaluation of climate change impacts on ecosystems and society in general. They are also intended for calibration and validation of satellite-based Earth observation and monitoring efforts, such as assessment of evapotranspiration from land and vegetation surfaces using surface energy balance approaches. In this paper, 15 years of Skukuza eddy covariance data, i.e. from 2000 to 2014, were analysed for surface energy balance closure (EBC) and partitioning. The surface energy balance closure was evaluated using the ordinary least squares regression (OLS) of turbulent energy fluxes (sensible (H) and latent heat (LE)) against available energy (net radiation (Rn) less soil heat (G)), and the energy balance ratio (EBR). Partitioning of the surface energy during the wet and dry seasons was also investigated, as well as how it is affected by atmospheric vapour pressure deficit (VPD), and net radiation. After filtering years with low-quality data (2004-2008), our results show an overall mean EBR of 0.93. Seasonal variations of EBR also showed the wet season with 1.17 and spring (1.02) being closest to unity, with the dry season (0.70) having the highest imbalance. Nocturnal surface energy closure was very low at 0.26, and this was linked to low friction velocity during night-time, with results showing an increase in closure with increase in friction velocity. The energy partition analysis showed that sensible heat flux is the dominant portion of net radiation, especially between March and October, followed by latent heat flux, and lastly the soil heat flux, and during the wet season where latent heat flux dominated sensible heat flux. An increase in net radiation was characterized by an increase in both LE and H, with LE showing a higher rate of increase than H in the wet season, and the reverse happening during the dry season. An increase in VPD is correlated with a decrease in LE and increase in H during the wet season, and an increase in both fluxes during the dry season. © 2017 Author(s). Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/79124
Appears in Collections: 气候变化事实与影响
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作者单位: Earth Observation Group, Natural Resources and Environment, Council for Scientific and Industrial Research, Pretoria, South Africa; Department of Water Resources, Faculty of Geo-Information Science and Earth Observation (ITC), University of Twente, Enschede, Netherlands; Department of Geography Geoinformatics and Meteorology, University of Pretoria, Pretoria, South Africa; Nuffield Department of Primary Care Health Sciences, University of Oxford, Oxford, United Kingdom; University of Limpopo, Risk and Vulnerability Centre, Sovenga, South Africa
Recommended Citation:
Majozi N,P,, Mannaerts C,et al. Analysing surface energy balance closure and partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger National Park, South Africa[J]. Hydrology and Earth System Sciences,2017-01-01,21(7)