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| Titel |
A global carbon assimilation system based on a dual optimization method |
| VerfasserIn |
H. Zheng, Y. Li, J. M. Chen, T. Wang, Q. Huang, W. X. Huang, L. H. Wang, S. M. Li, W. P. Yuan, X. Zheng, S. P. Zhang, Z. Q. Chen, F. Jiang |
| 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 ; 12, no. 4 ; Nr. 12, no. 4 (2015-02-24), S.1131-1150 |
| Datensatznummer |
250117827
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| Publikation (Nr.) |
 copernicus.org/bg-12-1131-2015.pdf |
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| Zusammenfassung |
| Ecological models are effective tools for simulating the distribution
of global carbon sources and sinks. However, these models often
suffer from substantial biases due to inaccurate simulations of
complex ecological processes. We introduce a set of scaling factors
(parameters) to an ecological model on the basis of plant functional
type (PFT) and latitudes. A global carbon assimilation system
(GCAS-DOM) is developed by employing a dual optimization method
(DOM) to invert the time-dependent ecological model parameter state
and the net carbon flux state simultaneously. We use GCAS-DOM to
estimate the global distribution of the CO2 flux on
1° × 1° grid cells for the period from 2001 to
2007. Results show that land and ocean absorb −3.63 ± 0.50 and −1.82 ±
0.16 Pg C yr−1, respectively. North America, Europe
and China contribute −0.98 ± 0.15,
−0.42 ± 0.08 and −0.20 ±
0.29 Pg C yr−1, respectively. The uncertainties in
the flux after optimization by GCAS-DOM have been remarkably reduced
by more than 60%. Through parameter optimization, GCAS-DOM can
provide improved estimates of the carbon flux for each
PFT. Coniferous forest (−0.97 ± 0.27 Pg C yr−1)
is the largest contributor to the global carbon sink. Fluxes of
once-dominant deciduous forest generated by the Boreal Ecosystems
Productivity Simulator (BEPS) are reduced to
−0.78 ± 0.23 Pg C yr−1, the third largest
carbon sink. |
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