Analysing surface energy balance closure and partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger National Park, South Africa

Show simple item record

dc.contributor.author Majozi, Nobuhle P.
dc.contributor.author Mannaerts, Chris M.
dc.contributor.author Ramoelo, Abel
dc.contributor.author Mathieu, Renaud
dc.contributor.author Nickless, Alecia
dc.contributor.author Verhoef, Wouter
dc.date.accessioned 2017-09-01T06:06:09Z
dc.date.available 2017-09-01T06:06:09Z
dc.date.issued 2017-07-10
dc.description.abstract 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. en_ZA
dc.description.department Geography, Geoinformatics and Meteorology en_ZA
dc.description.librarian am2017 en_ZA
dc.description.sponsorship This study was supported by the Council for Scientific and Industrial Research under the project entitled “Monitoring of water availability using geo-spatial data and earth observations”, and the National Research Foundation under the Thuthuka PhD cycle grant. en_ZA
dc.description.uri https://www.hydrology-and-earth-system-sciences.net en_ZA
dc.identifier.citation Majozi, N.P., Mannaerts, C.M., Ramoelo, A., Mathieu, R., Nickless, A. & Verhoef, W. 2017, 'Analysing surface energy balance closure and partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger National Park, South Africa', Hydrology and Earth System Sciences, vol. 21, pp. 3401-3415. en_ZA
dc.identifier.issn 1027-5606 (print)
dc.identifier.issn 1607-7938 (online)
dc.identifier.other 10.5194/hess-21-3401-2017
dc.identifier.uri http://hdl.handle.net/2263/62160
dc.language.iso en en_ZA
dc.publisher European Geosciences Union en_ZA
dc.rights © Author(s) 2017. This work is distributed under the Creative Commons Attribution 3.0 License. en_ZA
dc.subject Flux towers en_ZA
dc.subject Climate change en_ZA
dc.subject Monitoring en_ZA
dc.subject Grassland en_ZA
dc.subject Fluxes en_ZA
dc.subject Forest en_ZA
dc.subject Wet season en_ZA
dc.subject Energy balance closure (EBC) en_ZA
dc.subject Partitioning en_ZA
dc.subject Energy balance ratio (EBR) en_ZA
dc.title Analysing surface energy balance closure and partitioning over a semi-arid savanna FLUXNET site in Skukuza, Kruger National Park, South Africa en_ZA
dc.type Article en_ZA


Files in this item

This item appears in the following Collection(s)

Show simple item record