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| Titel |
Carbon cycle uncertainty in the Alaskan Arctic |
| VerfasserIn |
J. B. Fisher, M. Sikka, W. C. Oechel, D. N. Huntzinger, J. R. Melton, C. D. Koven, A. Ahlstrom, M. A. Arain, I. Baker, J. M. Chen, P. Ciais, C. Davidson, M. Dietze, B. El-Masri, D. Hayes, C. Huntingford, A. K. Jain, P. E. Levy, M. R. Lomas, B. Poulter, D. Price, A. K. Sahoo, K. Schaefer, H. Tian, E. Tomelleri, H. Verbeeck, N. Viovy, R. Wania, N. Zeng, C. E. Miller |
| 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. 15 ; Nr. 11, no. 15 (2014-08-14), S.4271-4288 |
| Datensatznummer |
250117547
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| Publikation (Nr.) |
 copernicus.org/bg-11-4271-2014.pdf |
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| Zusammenfassung |
| Climate change is leading to a disproportionately large warming in the high
northern latitudes, but the magnitude and sign of the future carbon balance
of the Arctic are highly uncertain. Using 40 terrestrial biosphere models for
the Alaskan Arctic from four recent model intercomparison projects – NACP
(North American Carbon Program) site and regional syntheses, TRENDY (Trends
in net land atmosphere carbon exchanges), and WETCHIMP (Wetland and Wetland
CH4 Inter-comparison of Models Project) – we provide a baseline of
terrestrial carbon cycle uncertainty, defined as the multi-model standard
deviation (σ) for each quantity that follows. Mean annual absolute
uncertainty was largest for soil carbon (14.0 ± 9.2 kg C m−2),
then gross primary production (GPP)
(0.22 ± 0.50 kg C m−2 yr−1), ecosystem respiration (Re)
(0.23 ± 0.38 kg C m−2 yr−1), net primary production (NPP)
(0.14 ± 0.33 kg C m−2 yr−1), autotrophic respiration (Ra)
(0.09 ± 0.20 kg C m−2 yr−1), heterotrophic respiration
(Rh) (0.14 ± 0.20 kg C m−2 yr−1), net ecosystem exchange
(NEE) (−0.01 ± 0.19 kg C m−2 yr−1), and CH4 flux
(2.52 ± 4.02 g CH4 m−2 yr−1). There were no
consistent spatial patterns in the larger Alaskan Arctic and boreal regional
carbon stocks and fluxes, with some models showing NEE for Alaska as a strong
carbon sink, others as a strong carbon source, while still others as carbon
neutral. Finally, AmeriFlux data are used at two sites in the Alaskan Arctic
to evaluate the regional patterns; observed seasonal NEE was captured within
multi-model uncertainty. This assessment of carbon cycle uncertainties may be
used as a baseline for the improvement of experimental and modeling
activities, as well as a reference for future trajectories in carbon cycling
with climate change in the Alaskan Arctic and larger boreal region. |
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