scholarly journals Modeling Surface Energy Fluxes over a Dehesa (Oak Savanna) Ecosystem Using a Thermal Based Two-Source Energy Balance Model (TSEB) I

2018 ◽  
Vol 10 (4) ◽  
pp. 567 ◽  
Author(s):  
Ana Andreu ◽  
William Kustas ◽  
Maria Polo ◽  
Arnaud Carrara ◽  
Maria González-Dugo
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Energy Balance Model ◽  
Balance Model ◽  
Oak Savanna ◽  
Energy Fluxes ◽  
Surface Energy Fluxes

scholarly journals Evaluation of a Two-Source Snow–Vegetation Energy Balance Model for Estimating Surface Energy Fluxes in a Rangeland Ecosystem

2014 ◽  
Vol 15 (1) ◽  
pp. 143-158 ◽  
Author(s):  
Cezar Kongoli ◽  
William P. Kustas ◽  
Martha C. Anderson ◽  
John M. Norman ◽  
Joseph G. Alfieri ◽  
...  
Keyword(s):  
Heat Flux ◽  
Energy Balance ◽  
Surface Energy ◽  
Snow Cover ◽  
Sensible Heat Flux ◽  
Energy Balance Model ◽  
Balance Model ◽  
Sensible Heat ◽  
Energy Fluxes ◽  
Surface Energy Fluxes

Abstract The utility of a snow–vegetation energy balance model for estimating surface energy fluxes is evaluated with field measurements at two sites in a rangeland ecosystem in southwestern Idaho during the winter of 2007: one site dominated by aspen vegetation and the other by sagebrush. Model parameterizations are adopted from the two-source energy balance (TSEB) modeling scheme, which estimates fluxes from the vegetation and surface substrate separately using remotely sensed measurements of land surface temperature. Modifications include development of routines to account for surface snowmelt energy flux and snow masking of vegetation. Comparisons between modeled and measured surface energy fluxes of net radiation and turbulent heat showed reasonable agreement when considering measurement uncertainties in snow environments and the simplified algorithm used for the snow surface heat flux, particularly on a daily basis. There was generally better performance over the aspen field site, likely due to more reliable input data of snow depth/snow cover. The model was robust in capturing the evolution of surface energy fluxes during melt periods. The model behavior was also consistent with previous studies that indicate the occurrence of upward sensible heat fluxes during daytime owing to solar heating of vegetation limbs and branches, which often exceeds the downward sensible heat flux driving the snowmelt. However, model simulations over aspen trees showed that the upward sensible heat flux could be reversed for a lower canopy fraction owing to the dominance of downward sensible heat flux over snow. This indicates that reliable vegetation or snow cover fraction inputs to the model are needed for estimating fluxes over snow-covered landscapes.

Modelling surface energy fluxes over a dehesa ecosystem using a two-source energy balance model and medium resolution satellite data

2013 ◽  
Author(s):  
A. Andreu ◽  
M. P. González-Dugo ◽  
W. P. Kustas ◽  
M. J. Polo ◽  
M. C. Anderson
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Satellite Data ◽  
Energy Balance Model ◽  
Balance Model ◽  
Energy Fluxes ◽  
Surface Energy Fluxes ◽  
Medium Resolution

Surface energy balance model of transpiration from variable canopy cover and evaporation from residue-covered or bare-soil systems

2009 ◽  
Vol 28 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Luis Octavio Lagos ◽  
Derrel L. Martin ◽  
Shashi B. Verma ◽  
Andrew Suyker ◽  
Suat Irmak
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Canopy Cover ◽  
Bare Soil ◽  
Energy Balance Model ◽  
Balance Model ◽  
Soil Systems

scholarly journals Using a thermal-based two source energy balance model with time-differencing to estimate surface energy fluxes with day–night MODIS observations

2013 ◽  
Vol 17 (7) ◽  
pp. 2809-2825 ◽  
Author(s):  
R. Guzinski ◽  
M. C. Anderson ◽  
W. P. Kustas ◽  
H. Nieto ◽  
I. Sandholt
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
The United States ◽  
Surface Fluxes ◽  
Diurnal Changes ◽  
Energy Fluxes ◽  
Surface Energy Fluxes ◽  
Vegetation Fraction ◽  
Geostationary Satellites ◽  
Green Vegetation

Abstract. The Dual Temperature Difference (DTD) model, introduced by Norman et al. (2000), uses a two source energy balance modelling scheme driven by remotely sensed observations of diurnal changes in land surface temperature (LST) to estimate surface energy fluxes. By using a time-differential temperature measurement as input, the approach reduces model sensitivity to errors in absolute temperature retrieval. The original formulation of the DTD required an early morning LST observation (approximately 1 h after sunrise) when surface fluxes are minimal, limiting application to data provided by geostationary satellites at sub-hourly temporal resolution. The DTD model has been applied primarily during the active growth phase of agricultural crops and rangeland vegetation grasses, and has not been rigorously evaluated during senescence or in forested ecosystems. In this paper we present modifications to the DTD model that enable applications using thermal observations from polar orbiting satellites, such as Terra and Aqua, with day and night overpass times over the area of interest. This allows the application of the DTD model in high latitude regions where large viewing angles preclude the use of geostationary satellites, and also exploits the higher spatial resolution provided by polar orbiting satellites. A method for estimating nocturnal surface fluxes and a scheme for estimating the fraction of green vegetation are developed and evaluated. Modification for green vegetation fraction leads to significantly improved estimation of the heat fluxes from the vegetation canopy during senescence and in forests. When the modified DTD model is run with LST measurements acquired with the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Terra and Aqua satellites, generally satisfactory agreement with field measurements is obtained for a number of ecosystems in Denmark and the United States. Finally, regional maps of energy fluxes are produced for the Danish Hydrological ObsErvatory (HOBE) in western Denmark, indicating realistic patterns based on land use.

scholarly journals Evaluation of the Simple Urban Energy Balance Model Using Selected Data from 1-yr Flux Observations at Two Cities

2009 ◽  
Vol 48 (4) ◽  
pp. 693-715 ◽  
Author(s):  
Toru Kawai ◽  
Mohammad Kholid Ridwan ◽  
Manabu Kanda
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Surface Energy Balance ◽  
Sensible Heat Flux ◽  
Energy Balance Model ◽  
Balance Model ◽  
Wave Radiation ◽  
Urban Energy Balance ◽  
Two Cities ◽  
Urban Energy

Abstract The authors’ objective was to apply the Simple Urban Energy Balance Model for Mesoscale Simulation (SUMM) to cities. Data were selected from 1-yr flux observations conducted at three sites in two cities: one site in Kugahara, Japan (Ku), and two sites in Basel, Switzerland (U1 and U2). A simple vegetation scheme was implemented in SUMM to apply the model to vegetated cities, and the surface energy balance and radiative temperature TR were evaluated. SUMM generally reproduced seasonal and diurnal trends of surface energy balance and TR at Ku and U2, whereas relatively large errors were obtained for the daytime results of sensible heat flux QH and heat storage ΔQS at U1. Overall, daytime underestimations of QH and overestimations of ΔQS and TR were common. These errors were partly induced by the poor parameterization of the natural logarithm of the ratio of roughness length for momentum to heat (κB−1); that is, the observed κB−1 values at vegetated cities were smaller than the simulated values. The authors proposed a new equation for predicting this coefficient. This equation accounts for the existence of vegetation and improves the common errors described above. With the modified formula for κB−1, simulated net all-wave radiation and TR agreed well with observed values, regardless of site and season. However, at U1, simulated QH and ΔQS were still overestimated and underestimated, respectively, relative to observed values.

scholarly journals Evapotranspiration and Surface Energy Fluxes Estimation Using the Landsat-7 Enhanced Thematic Mapper Plus Image over a Semiarid Agrosystem in the North-West of Algeria

2017 ◽  
Vol 32 (4) ◽  
pp. 691-702 ◽  
Author(s):  
Nehal Laounia ◽  
Hamimed Abderrahmane ◽  
Khaldi Abdelkader ◽  
Souidi Zahira ◽  
Zaagane Mansour
Keyword(s):  
Energy Balance ◽  
Surface Energy ◽  
Heat Fluxes ◽  
Actual Evapotranspiration ◽  
Semiarid Region ◽  
Energy Fluxes ◽  
North West ◽  
Surface Energy Fluxes ◽  
Landsat 7 ◽  
Energy Balance Approach

Abstract Monitoring evapotranspiration and surface energy fluxes over a range of spatial and temporal scales is crucial for many agroenvironmental applications. Different remote sensing based energy balance models have been developed, to estimate evapotranspiration at both field and regional scales. In this contribution, METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration), has been applied for the estimation of actual evapotranspiration in the Ghriss plain in Mascara (western Algeria), a semiarid region with heterogeneous surface conditions. Four images acquired during 2001 and 2002 by the Landsat-7 satellite were used. The METRIC model followed an energy balance approach, where evapotranspiration is estimated as the residual term when net radiation, sensible and soil heat fluxes are known. Different moisture indicators derived from the evapotranspiration were then calculated: reference evapotranspiration fraction, Priestley-Taylor parameter and surface resistance to evaporation. The evaluation of evapotranspiration and surface energy fluxes are accurate enough for the spatial variations of evapotranspiration rather satisfactory than sophisticated models without having to introduce an important number of parameters in input with difficult accessibility in routine. In conclusion, the results suggest that METRIC can be considered as an operational approach to predict actual evapotranspiration from agricultural areas having limited amount of ground information.

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