Bassinot, Franck C. et al. (2011): Holocene evolution of summer winds and marine productivity in the tropical Indian Ocean in response to insolation forcing; data-model comparison
Leg/Site/Hole:
Related Expeditions:
ODP 117 ODP 117 723
Identifier:
ID:
2012-046920
Type:
georefid
Creator:
Name:
Bassinot, Franck C.
Affiliation:
CNRS-CEA-USVQ-IPSL, Laboratoire des Sciences du Climat et de l'Environnement, Gif-sur-Yvette, France
Role:
author
Name:
Marzin, Charline
Affiliation:
Universite de la Mediterranee, France
Role:
author
Name:
Braconnot, Pascale
Affiliation:
Role:
author
Name:
Marti, Olivier
Affiliation:
Role:
author
Name:
Mathien-Blard, E.
Affiliation:
Role:
author
Name:
Lombard, F.
Affiliation:
Role:
author
Name:
Bopp, Laurent
Affiliation:
Role:
author
Identification:
Title:
Holocene evolution of summer winds and marine productivity in the tropical Indian Ocean in response to insolation forcing; data-model comparison
Year:
2011
Source:
Climate of the Past
Publisher:
Copernicus, Katlenburg-Lindau, International
Volume:
7
Issue:
3
Pages:
815-829
Abstract:
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 approximately 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 approximately 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.
Language:
English
Genre:
Serial
Rights:
URL:
Coverage: Geographic coordinates: North:18.0305 West:57.3633 East:
57.3700 South:7.0300
Keywords: Quaternary geology; Arabian Peninsula; Arabian Sea; Asia; biochemistry; C-14; carbon; Cenozoic; chlorophyll; climate forcing; currents; Foraminifera; Globigerinacea; Globigerinidae; Globigerinoides; Globigerinoides bulloides; Holocene; India; Indian Ocean; Indian Peninsula; insolation; Invertebrata; isotopes; Leg 117; lower Holocene; marine environment; microfossils; monsoons; Ocean Drilling Program; ODP Site 723; Oman; organic compounds; paleocurrents; paleoenvironment; particulate materials; phytoplankton; pigments; plankton; porphyrins; productivity; Protista; Quaternary; radioactive isotopes; Rotaliina; salinity; tropical environment; upwelling; winds;
.