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| Titel |
Glacial-interglacial variability in ocean oxygen and phosphorus in a global biogeochemical model |
| VerfasserIn |
V. Palastanga, C. P. Slomp, C. Heinze |
| 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 (2013-02-11), S.945-958 |
| Datensatznummer |
250017511
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| Publikation (Nr.) |
 copernicus.org/bg-10-945-2013.pdf |
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| Zusammenfassung |
| Increased transfer of particulate matter from continental shelves to the open
ocean during glacials may have had a major impact on the biogeochemistry of
the ocean. Here, we assess the response of the coupled oceanic cycles of
oxygen, carbon, phosphorus, and iron to the input of particulate organic
carbon and reactive phosphorus from shelves. We use a biogeochemical ocean
model and specifically focus on the Last Glacial Maximum (LGM). When compared
to an interglacial reference run, our glacial scenario with shelf input shows
major increases in ocean productivity and phosphorus burial, while mean
deep-water oxygen concentrations decline. There is a downward expansion of the
oxygen minimum zones (OMZs) in the Atlantic and Indian Ocean, while the
extension of the OMZ in the Pacific is slightly reduced. Oxygen
concentrations below 2000 m also decline but bottom waters do not become
anoxic. The model simulations show when shelf input of particulate organic
matter and particulate reactive P is considered, low oxygen areas in the
glacial ocean expand, but concentrations are not low enough to generate wide
scale changes in sediment biogeochemistry and sedimentary phosphorus
recycling. Increased reactive phosphorus burial in the open ocean during the
LGM in the model is related to dust input, notably over the southwest
Atlantic and northwest Pacific, whereas input of material from shelves
explains higher burial fluxes in continental slope and rise regions. Our
model results are in qualitative agreement with available data and reproduce
the strong spatial differences in the response of phosphorus burial to
glacial-interglacial change. Our model results also highlight the need for
additional sediment core records from all ocean basins to allow further
insight into changes in phosphorus, carbon and oxygen dynamics in the ocean
on glacial-interglacial timescales. |
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