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| Titel |
Using a thermal-based two source energy balance model with time-differencing to estimate surface energy fluxes with day–night MODIS observations |
| VerfasserIn |
R. Guzinski, M. C. Anderson, W. P. Kustas, H. Nieto, I. Sandholt |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1027-5606
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| Digitales Dokument |
URL |
| Erschienen |
In: Hydrology and Earth System Sciences ; 17, no. 7 ; Nr. 17, no. 7 (2013-07-16), S.2809-2825 |
| Datensatznummer |
250018938
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| Publikation (Nr.) |
 copernicus.org/hess-17-2809-2013.pdf |
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| Zusammenfassung |
| 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. |
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