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| Titel |
Holocene evolution of summer winds and marine productivity in the tropical Indian Ocean in response to insolation forcing: data-model comparison |
| VerfasserIn |
F. C. Bassinot, C. Marzin, P. Braconnot, O. Marti, E. Mathien-Blard, F. Lombard, L. Bopp |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1814-9324
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| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 7, no. 3 ; Nr. 7, no. 3 (2011-07-28), S.815-829 |
| Datensatznummer |
250004612
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| Publikation (Nr.) |
 copernicus.org/cp-7-815-2011.pdf |
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| Zusammenfassung |
The relative abundance of Globigerinoides bulloides was used to infer Holocene paleo-productivity
changes on the Oman margin and at the southern tip of India. Today, the
primary productivity at both sites reaches its maximum during the summer season, when
monsoon winds result in local Eckman pumping, which brings more nutrients to
the surface. On a millennium time-scale, however, the % G. bulloides records indicate
an opposite evolution of paleo-productivity at these sites through the
Holocene. The Oman Margin productivity was maximal at ~9 ka (boreal
summer insolation maximum) and has decreased since then, suggesting a direct
response to insolation forcing. On the contrary, the productivity at the
southern tip of India was minimum at ~9 ka, and strengthened towards
the present.
Paleo-reconstructions of wind patterns, marine productivity and foraminifera
assemblages were obtained using the IPSL-CM4 climate model coupled to the
PISCES marine biogeochemical model and the FORAMCLIM ecophysiological model.
These reconstructions are fully coherent with the marine core data. They
confirm that the evolution of particulate export production and foraminifera
assemblages at our two sites were directly linked with the strength of
the upwelling. Model simulations at 9 ka and 6 ka BP show that the relative
evolution between the two sites since the early Holocene can be explained by
the weakening but also the southward shift of monsoon winds over the Arabian
Sea during boreal summer. |
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