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| Titel |
Uncertainty analysis of computational methods for deriving sensible heat flux values from scintillometer measurements |
| VerfasserIn |
P. A. Solignac, A. Brut, J.-L. Selves, J.-P. Béteille, J.-P. Gastellu-Etchegorry, P. Keravec, P. Beziat, E. Ceschia |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 2, no. 2 ; Nr. 2, no. 2 (2009-11-18), S.741-753 |
| Datensatznummer |
250000580
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| Publikation (Nr.) |
 copernicus.org/amt-2-741-2009.pdf |
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| Zusammenfassung |
| The use of scintillometers to determine sensible heat fluxes is now common in
studies of land-atmosphere interactions. The main interest in these
instruments is due to their ability to quantify energy distributions at the
landscape scale, as they can calculate sensible heat flux values over long
distances, in contrast to Eddy Covariance systems. However, scintillometer
data do not provide a direct measure of sensible heat flux, but require
additional data, such as the Bowen ratio (β), to provide flux values.
The Bowen ratio can either be measured using Eddy Covariance systems or
derived from the energy balance closure. In this work, specific requirements
for estimating energy fluxes using a scintillometer were analyzed, as well as
the accuracy of two flux calculation methods. We first focused on the
classical method (used in standard softwares) and we analysed the impact of
the Bowen ratio on flux value and uncertainty. For instance, an averaged
Bowen ratio (β) of less than 1 proved to be a significant source of
measurement uncertainty. An alternative method, called the "β-closure
method", for which the Bowen ratio measurement is not necessary, was also
tested. In this case, it was observed that even for low β values, flux
uncertainties were reduced and scintillometer data were well correlated with
the Eddy Covariance results. Besides, both methods should tend to the same
results, but the second one slightly underestimates H while β
decreases (<5%). |
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