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| Titel |
Simultaneous assimilation of satellite and eddy covariance data for improving terrestrial water and carbon simulations at a semi-arid woodland site in Botswana |
| VerfasserIn |
T. Kato, W. Knorr, M. Scholze, E. Veenendaal, T. Kaminski, J. Kattge, N. Gobron |
| 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 ; 10, no. 2 ; Nr. 10, no. 2 (2013-02-05), S.789-802 |
| Datensatznummer |
250017501
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| Publikation (Nr.) |
 copernicus.org/bg-10-789-2013.pdf |
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| Zusammenfassung |
Terrestrial productivity in semi-arid woodlands is strongly susceptible to
changes in precipitation, and semi-arid woodlands constitute an important
element of the global water and carbon cycles. Here, we use the Carbon Cycle
Data Assimilation System (CCDAS) to investigate the key parameters
controlling ecological and hydrological activities for a semi-arid savanna
woodland site in Maun, Botswana. Twenty-four eco-hydrological process
parameters of a terrestrial ecosystem model are optimized against two data
streams separately and simultaneously: daily averaged latent heat flux (LHF)
derived from eddy covariance measurements, and decadal fraction of absorbed
photosynthetically active radiation (FAPAR) derived from the Sea-viewing Wide
Field-of-view Sensor (SeaWiFS).
Assimilation of both data streams LHF and FAPAR for the years 2000 and 2001
leads to improved agreement between measured and simulated quantities not
only for LHF and FAPAR, but also for photosynthetic CO2 uptake. The
mean uncertainty reduction (relative to the prior) over all parameters is
14.9% for the simultaneous assimilation of LHF and FAPAR, 8.5% for
assimilating LHF only, and 6.1% for assimilating FAPAR only. The
set of parameters with the highest uncertainty reduction is similar between
assimilating only FAPAR or only LHF. The highest uncertainty reduction for
all three cases is found for a parameter quantifying maximum plant-available
soil moisture. This indicates that not only LHF but also satellite-derived
FAPAR data can be used to constrain and indirectly observe hydrological
quantities. |
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