The correction of soil heat flux measurements to derive an accurate surface energy balance by the Bowen ratio method

1997 ◽  
Vol 188-189 ◽  
pp. 453-465 ◽  
Author(s):  
Alain Passerat de Silans ◽  
Bruno A. Monteny ◽  
Jean Paul Lhomme
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Bowen Ratio ◽  
Soil Heat Flux ◽  
Ratio Method ◽  
Flux Measurements

Surface energy balance closure in an arid region: role of soil heat flux

2004 ◽  
Vol 122 (1-2) ◽  
pp. 21-37 ◽  
Author(s):  
B.G Heusinkveld ◽  
A.F.G Jacobs ◽  
A.A.M Holtslag ◽  
S.M Berkowicz
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Surface Energy ◽  
Arid Region ◽  
Surface Energy Balance ◽  
Soil Heat Flux ◽  
Energy Balance Closure

scholarly journals The Analytical Objective Hysteresis Model (AnOHM v1.0): Methodology to Determine Bulk Storage Heat Flux Coefficients

2017 ◽  
Author(s):  
Ting Sun ◽  
Zhi-Hua Wang ◽  
Walter Oechel ◽  
Sue Grimmond
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Surface Energy ◽  
Urban Areas ◽  
Surface Energy Balance ◽  
Bowen Ratio ◽  
Stochastic Approach ◽  
Wave Radiation ◽  
Hysteresis Model ◽  
Advection Diffusion Equation

Abstract. The net storage heat flux is not only a large part of the urban surface energy balance (SEB) but its determination remains a significant challenge. The diurnal hysteresis behaviour found between the net storage heat flux (ΔQS) and net all-wave radiation (Q*) has been captured in the Objective Hysteresis Model (OHM) parametrization of ΔQS. Although, successfully used in urban areas, the limited availability of coefficients for OHM hampers application. To facilitate use, and enhance physical interpretations of the OHM coefficients, an analytical solution of the 1-dimensional advection-diffusion equation of coupled heat and liquid water transport in conjunction with the SEB is conducted, allowing development of AnOHM (Analytical Objective Hysteresis Model). A sensitivity test of AnOHM to surface properties and hydrometeorological forcing is undertaken using a stochastic approach (the Subset Simulation). From this albedo, Bowen ratio and bulk transfer coefficient, solar radiation and wind speed are identified as being critical. AnOHM, driven by local meteorological conditions at five different land use areas, is shown to simulate the ΔQS flux well (RMSE values of ~30 W m−2). The intra-annual dynamics of OHM coefficients to are explored which offers significant potential to enhance modelling of the surface energy balance over a wider range of conditions.

scholarly journals Evaluation of the Surface Energy Balance System (SEBS) applied to ASTER imagery with flux-measurements at the SPARC 2004 site (Barrax, Spain)

2009 ◽  
Vol 13 (7) ◽  
pp. 1337-1347 ◽  
Author(s):  
J. van der Kwast ◽  
W. Timmermans ◽  
A. Gieske ◽  
Z. Su ◽  
A. Olioso ◽  
...  
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Surface Energy ◽  
Land Cover ◽  
Surface Energy Balance ◽  
Sensible Heat Flux ◽  
Sensible Heat ◽  
Balance System ◽  
Flux Measurements ◽  
Aerodynamic Parameters

Abstract. Accurate quantification of the amount and spatial variation of evapotranspiration is important in a wide range of disciplines. Remote sensing based surface energy balance models have been developed to estimate turbulent surface energy fluxes at different scales. The objective of this study is to evaluate the Surface Energy Balance System (SEBS) model on a landscape scale, using tower-based flux measurements at different land cover units during an overpass of the ASTER sensor over the SPARC 2004 experimental site in Barrax (Spain). A sensitivity analysis has been performed in order to investigate to which variable the sensible heat flux is most sensitive. Taking into account their estimation errors, the aerodynamic parameters (hc, z0M and d0) can cause large deviations in the modelling of sensible heat flux. The effect of replacement of empirical derivation of these aerodynamic parameters in the model by field estimates or literature values is investigated by testing two scenarios: the Empirical Scenario in which empirical equations are used to derive aerodynamic parameters and the Field Scenario in which values from field measurements or literature are used to replace the empirical calculations of the Empirical Scenario. In the case of a homogeneous land cover in the footprints of the measurements, the Field Scenario only resulted in a small improvement, compared to the Empirical Scenario. The Field Scenario can even worsen the result in the case of heterogeneous footprints, by creating sharp borders related to the land cover map. In both scenarios modelled fluxes correspond better with flux measurements over uniform land cover compared to cases where different land covers are mixed in the measurement footprint. Furthermore SEBS underestimates sensible heat flux especially over dry and sparsely vegetated areas, which is common in single-source models.

scholarly journals The Analytical Objective Hysteresis Model (AnOHM v1.0): methodology to determine bulk storage heat flux coefficients

2017 ◽  
Vol 10 (7) ◽  
pp. 2875-2890 ◽  
Author(s):  
Ting Sun ◽  
Zhi-Hua Wang ◽  
Walter C. Oechel ◽  
Sue Grimmond
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Surface Energy ◽  
Urban Areas ◽  
Surface Energy Balance ◽  
Bowen Ratio ◽  
Sensitivity Test ◽  
Wave Radiation ◽  
Hysteresis Model ◽  
Advection Diffusion Equation

Abstract. The net storage heat flux (ΔQS) is important in the urban surface energy balance (SEB) but its determination remains a significant challenge. The hysteresis pattern of the diurnal relation between the ΔQS and net all-wave radiation (Q∗) has been captured in the Objective Hysteresis Model (OHM) parameterization of ΔQS. Although successfully used in urban areas, the limited availability of coefficients for OHM hampers its application. To facilitate use, and enhance physical interpretations of the OHM coefficients, an analytical solution of the one-dimensional advection–diffusion equation of coupled heat and liquid water transport in conjunction with the SEB is conducted, allowing development of AnOHM (Analytical Objective Hysteresis Model). A sensitivity test of AnOHM to surface properties and hydrometeorological forcing is presented using a stochastic approach (subset simulation). The sensitivity test suggests that the albedo, Bowen ratio and bulk transfer coefficient, solar radiation and wind speed are most critical. AnOHM, driven by local meteorological conditions at five sites with different land use, is shown to simulate the ΔQS flux well (RMSE values of ∼ 30 W m−2). The intra-annual dynamics of OHM coefficients are explored. AnOHM offers significant potential to enhance modelling of the surface energy balance over a wider range of conditions and land covers.

Effects of the soil heat flux estimates on surface energy balance closure over a semi-arid grassland

2011 ◽  
Vol 25 (6) ◽  
pp. 774-782 ◽  
Author(s):  
Ping Yue ◽  
Qiang Zhang ◽  
Shengjie Niu ◽  
Hua Cheng ◽  
Xiyu Wang
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Soil Heat Flux ◽  
Energy Balance Closure ◽  
Semi Arid

Impacts of soil heat flux calculation methods on the surface energy balance closure

2015 ◽  
Vol 214-215 ◽  
pp. 189-200 ◽  
Author(s):  
Eric S. Russell ◽  
Heping Liu ◽  
Zhongming Gao ◽  
Dennis Finn ◽  
Brian Lamb
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Soil Heat Flux ◽  
Energy Balance Closure ◽  
Calculation Methods ◽  
Flux Calculation

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

2017 ◽  
Vol 21 (7) ◽  
pp. 3401-3415 ◽  
Author(s):  
Nobuhle P. Majozi ◽  
Chris M. Mannaerts ◽  
Abel Ramoelo ◽  
Renaud Mathieu ◽  
Alecia Nickless ◽  
...  
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Surface Energy ◽  
Latent Heat ◽  
Surface Energy Balance ◽  
Sensible Heat Flux ◽  
Dry Season ◽  
Energy Balance Closure ◽  
Net Radiation ◽  
Wet Season

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.

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