Early last glacial maximum in the southern Central Andes reveals northward shift of the westerlies at similar to 39 ka

Zech, Roland; Zech, Jana; Kull, Christoph; Kubrik, Peter W.; Veit, Heinz (2011). Early last glacial maximum in the southern Central Andes reveals northward shift of the westerlies at similar to 39 ka. Climate of the past, 7(1), pp. 41-46. Göttingen: Copernicus Publications 10.5194/cp-7-41-2011

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The latitudinal position of the southern westerlies has been suggested to be a key parameter for the climate on Earth. According to the general notion, the southern westerlies were shifted equatorward during the global Last Glacial Maximum (LGM: ~24–18 ka), resulting in reduced deep ocean ventilation, accumulation of old dissolved carbon, and low atmospheric CO2 concentrations. In order to test this notion, we applied surface exposure dating on moraines in the southern Central Andes, where glacial mass balances are particularly sensitive to changes in precipitation, i.e. to the latitudinal position of the westerlies. Our results provide robust evidence that the maximum glaciation occurred already at ~39 ka, significantly predating the global LGM. This questions the role of the westerlies for atmospheric CO2, and it highlights our limited understanding of the forcings of atmospheric circulation.

Item Type:

Journal Article (Original Article)

Division/Institute:

08 Faculty of Science > Institute of Geography
08 Faculty of Science > Institute of Geography > Physical Geography > Unit Biogeochemistry and Paleoclimate
08 Faculty of Science > Institute of Geography > Physical Geography > Unit Paleo-Geoecology

UniBE Contributor:

Zech, Roland; Zech, Jana; Kull, Christoph and Veit, Heinz

Subjects:

900 History > 910 Geography & travel

ISSN:

1814-9324

Publisher:

Copernicus Publications

Language:

English

Submitter:

Factscience Import

Date Deposited:

04 Oct 2013 14:26

Last Modified:

01 Oct 2015 16:30

Publisher DOI:

10.5194/cp-7-41-2011

Web of Science ID:

000288992700004

BORIS DOI:

10.7892/boris.9219

URI:

https://boris.unibe.ch/id/eprint/9219 (FactScience: 214904)

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