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| Titel |
Early last glacial maximum in the southern Central Andes reveals northward shift of the westerlies at ~39 ka |
| VerfasserIn |
R. Zech, J. Zech, Ch. Kull, P. W. Kubik, H. Veit |
| 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. 1 ; Nr. 7, no. 1 (2011-01-12), S.41-46 |
| Datensatznummer |
250004394
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| Publikation (Nr.) |
 copernicus.org/cp-7-41-2011.pdf |
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| Zusammenfassung |
| 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. |
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