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| Titel |
Burial-nutrient feedbacks amplify the sensitivity of atmospheric carbon dioxide to changes in organic matter remineralisation |
| VerfasserIn |
R. Roth, S. P. Ritz, F. Joos |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
2190-4979
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| Digitales Dokument |
URL |
| Erschienen |
In: Earth System Dynamics ; 5, no. 2 ; Nr. 5, no. 2 (2014-10-16), S.321-343 |
| Datensatznummer |
250115368
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| Publikation (Nr.) |
 copernicus.org/esd-5-321-2014.pdf |
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| Zusammenfassung |
| Changes in the marine remineralisation of particulate organic matter (POM)
and calcium carbonate potentially provide a positive feedback with
atmospheric CO2 and climate change. The responses to changes in
remineralisation length scales are systematically mapped with the Bern3D
ocean–sediment model for atmospheric CO2 and tracer fields for which
observations and palaeoproxies exist. Results show that the "sediment
burial-nutrient feedback" amplifies the response in atmospheric CO2 by
a factor of four to seven. A transient imbalance between the weathering flux
and the burial of organic matter and calcium carbonate lead to sustained
changes in the ocean's phosphate and alkalinity inventory and in turn in
surface nutrient availability, marine productivity, and atmospheric CO2.
It takes decades to centuries to reorganise tracers and fluxes within the
ocean, many millennia to approach equilibrium for burial fluxes, while
δ13C signatures are still changing 200 000 years after the
perturbation. At 1.7 ppm m−1, atmospheric CO2 sensitivity is
about fifty times larger for a unit change in the remineralisation depth of
POM than of calcium carbonate. The results highlight the role of organic
matter burial in atmospheric CO2 and the substantial impacts of
seemingly small changes in POM remineralisation. |
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