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| Titel |
Remotely sensed land-surface energy fluxes at sub-field scale in heterogeneous agricultural landscape and coniferous plantation |
| VerfasserIn |
R. Guzinski, H. Nieto, R. Jensen, G. Mendiguren |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1726-4170
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| Digitales Dokument |
URL |
| Erschienen |
In: Biogeosciences ; 11, no. 18 ; Nr. 11, no. 18 (2014-09-18), S.5021-5046 |
| Datensatznummer |
250117600
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| Publikation (Nr.) |
 copernicus.org/bg-11-5021-2014.pdf |
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| Zusammenfassung |
| In this study we evaluate a methodology for disaggregating land surface
energy fluxes estimated with the Two-Source Energy Balance (TSEB)-based
Dual-Temperature Difference (DTD) model which uses day and night polar
orbiting satellite observations of land surface temperature (LST) as a
remotely sensed input. The DTD model is run with MODIS input data at
a spatial resolution of around 1 km while the disaggregation uses Landsat
observations to produce fluxes at a nominal spatial resolution of 30 m. The
higher-resolution modelled fluxes can be directly compared against eddy
covariance (EC)-based flux tower measurements to ensure more accurate model
validation and also provide a better visualization of the fluxes' spatial
patterns in heterogeneous areas allowing for development of, for example,
more efficient irrigation practices. The disaggregation technique is
evaluated in an area covered by the Danish Hydrological Observatory (HOBE),
in the west of the Jutland peninsula, and the modelled fluxes are compared
against measurements from two flux towers: the first one in a heterogeneous
agricultural landscape and the second one in a homogeneous conifer
plantation. The results indicate that the coarse-resolution DTD fluxes
disaggregated at Landsat scale have greatly improved accuracy as compared to
high-resolution fluxes derived directly with Landsat data without the
disaggregation. At the agricultural site the disaggregated fluxes display
small bias and very high correlation (r ≈ 0.95) with EC-based
measurements, while at the plantation site the results are encouraging but
still with significant errors. In addition, we introduce a~modification to
the DTD model by replacing the "parallel" configuration of the resistances
to sensible heat exchange by the "series" configuration. The latter takes
into account the in-canopy air temperature and substantially improves the
accuracy of the DTD model. |
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