Land surface energy partitioning revisited: A novel approach based on single depth soil measurement

Yang, Jiachuan; Wang, Zhi‐Hua

doi:10.1002/2014gl062041

Cited by 34 publications

(33 citation statements)

References 34 publications

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“…In addition to the calorimetric method, numerous other approaches aiming to improve the accuracy of G 0 calculations have been proposed, including calculating G 0 as a simple fraction of R n , as a linear or nonlinear function of R n , and using analytical solutions of the thermal diffusion equations [ Massman , , ; Wang and Bras , ; Heusinkveld et al , ; Liebethal and Foken , ; Bennett et al , ; Yang and Wang , ; Hsieh et al , ; Gao et al , ; Leuning et al , ; Wang , ; Wang and Bou‐Zeid , ; Yang and Wang , ]. These G 0 methods have been evaluated using the calorimetric method as a reference considering its reliability [ Heusinkveld et al , ; Liebethal and Foken , ; Wang and Bou‐Zeid , ; Li et al , ; Russell et al , ].…”

Section: Introductionmentioning

confidence: 99%

A novel approach to evaluate soil heat flux calculation: An analytical review of nine methods

et al. 2017

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There are no direct methods to evaluate calculated soil heat flux (SHF) at the surface (G0). Instead, validation and cross evaluation of methods for calculating G0 usually rely on the conventional calorimetric method or the degree of the surface energy balance closure. However, there is uncertainty in the calorimetric method itself, and factors apart from G0 also contribute to nonclosure of the surface energy balance. Here we used a novel approach to evaluate nine different methods for calculating SHF, including the calorimetric method and methods based on analytical solutions of the heat diffusion equation. The SHF (Gz) measured by a self‐calibrating SHF plate at a depth of z = 5 cm below the surface (hereafter Gm_5cm) was deployed as a reference. Each SHF calculation method was assessed by comparing the calculated Gz at the same depth (hereafter Gc_5cm) with Gm_5cm. The calorimetric method and simple measurement method performed best in determining Gc_5cm but still underestimated Gm_5cm by 19% during the daytime. Possible causes for this underestimation include errors and uncertainties in SHF measurements and soil thermal properties, as well as the phase lag between Gc_5cm and Gm_5cm. Our results indicate that the calorimetric method achieves the most accurate SHF estimates if self‐calibrating SHF plates are deployed at two depths (e.g., 5 cm and 10 cm), soil temperature and water content measurements are made in a few depths between the two plates, and soil thermal properties are accurately quantified.

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Section: Introductionmentioning

confidence: 99%

A novel approach to evaluate soil heat flux calculation: An analytical review of nine methods

et al. 2017

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“…Evaluation against in situ measurements verified accuracy of the MEP model over both land and water surfaces (Wang and Bras ; Wang et al ). The second method is the numerical procedure developed by Yang and Wang (). Using Green's function approach, the method is able to reconstruct soil thermal field from a single depth soil measurement of either temperature or heat flux (Wang ; Wang and Bou‐Zeid ).…”

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confidence: 99%

A novel approach for unraveling the energy balance of water surfaces with a single depth temperature measurement

Yang

Wang

et al. 2016

Limnology & Oceanography

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The partitioning of solar energy over the Earth's surface drives weather and climate of the coupled land–ocean–atmosphere system. Over water surfaces, the evolution of water temperatures at a given depth in the mixed layer implicitly contains the signature of surface energy partitioning, and as such it can be used to diagnose the surface energy balance. In this study, we develop a novel numerical scheme by combining the Green's function approach and linear stability analysis to estimate the water surface energy balance using water temperature measurement at a single depth. The proposed method is capable of predicting water temperature in the mixed layer, and solving for the components of the surface energy budgets with physically based schemes. Evaluation against in situ measurement and the maximum entropy production method demonstrates that this approach is robust and of good accuracy. It is found that performance of the proposed method depends strongly on the accurate estimation of turbulent thermal diffusivity from in situ measurements, which carries information of meteorological and limnological conditions. Without explicitly using wind speed or temperature/moisture gradient, the proposed approach reduces uncertainty and potential error associated with meteorological measurements in estimation of water surface energy balance.

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“…To analytically track the heat conduction process in solid medium, a Green’s function approach can be adopted (Wang et al, 2011; Yang and Wang, 2014), and the subsurface temperature distribution for the urban landscape is given by the Duhamel’s Principle (Carslaw and Jaeger, 1959) as

T true(z, t true) = T_{i} + \int_{0}^{t} Q_{v} (t - τ) d g (z, τ)

…”

Section: Methodsmentioning

confidence: 99%

Thermodynamic characterisation of urban nocturnal cooling

Wang

2017

Heliyon

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Nocturnal cooling of urban areas governs the evolution of thermal state and many thermal-driven environmental issues in cities, especially those suffer strong urban heat island (UHI) effect. Advances in the fundamental understanding of the underlying physics of nighttime UHI involve disentangling complex contributing effects and remains an open challenge. In this study, we develop new numerical algorithms to characterize the thermodynamics of urban nocturnal cooling based on solving the energy balance equations for both the landscape surface and the overlying atmosphere. Further, a scaling law is proposed to relate the UHI intensity to a range of governing mechanisms, including the vertical and horizontal transport of heat in the surface layer, the urban-rural breeze, and the possible urban expansion. The accuracy of proposed methods is evaluated against in-situ urban measurements collected in cities with different geographic and climatic conditions. It is found that the vertical and horizontal contributors modulate the nocturnal UHI at distinct elevation in the atmospheric boundary layer.

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Land surface energy partitioning revisited: A novel approach based on single depth soil measurement

Cited by 34 publications

References 34 publications

A novel approach to evaluate soil heat flux calculation: An analytical review of nine methods

A novel approach to evaluate soil heat flux calculation: An analytical review of nine methods

A novel approach for unraveling the energy balance of water surfaces with a single depth temperature measurement

Thermodynamic characterisation of urban nocturnal cooling

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