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| Titel |
Assessment of sea surface temperature changes in the Gulf of Cadiz during the last 30 ka: implications for glacial changes in the regional hydrography |
| VerfasserIn |
A. Penaud, F. Eynaud, A. Voelker, M. Kageyama, F. Marret, J. L. Turon, D. Blamart, T. Mulder, L. Rossignol |
| 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 ; 8, no. 8 ; Nr. 8, no. 8 (2011-08-23), S.2295-2316 |
| Datensatznummer |
250006085
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| Publikation (Nr.) |
 copernicus.org/bg-8-2295-2011.pdf |
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| Zusammenfassung |
| New dinocyst analyses were conducted on core MD99-2339 retrieved from the
central Gulf of Cadiz. Dinocyst and foraminiferal assemblages from this core
are combined with existing data off SW Portugal and NW Morocco to
investigate past hydrological and primary productivity regimes in the
subtropical NE Atlantic Ocean over the last 30 ka. Our results have revealed
highest upwelling intensity during Heinrich Stadial 1 (HS 1) and the Younger
Dryas and weaker upwelling cells during the Last Glacial Maximum (LGM) and
HS 2, off the SW Iberian and NW Moroccan margins. Similar assemblages
between the Gulf of Cadiz and the NW Moroccan margin, and distinct species
off Portugal, were observed during the cold climatic extremes that
punctuated the last 30 ka. This pattern has been linked to the occurrence of
a hydrological structure between SW Iberia and Cadiz during the last glacial
period, perhaps similar to the modern Azores Front. This front was probably
responsible locally for heterotrophic dinocysts found in the Gulf of Cadiz
during the last glacial period, even if this sector is not conductive to
upwelling phenomena by Ekman transport. Regional reconstructions of
paleo-sea-surface temperatures (SSTs) using dinocyst and foraminiferal
transfer functions, as well as alkenones, are also discussed and depict
coherent scenarios over the last 30 ka. Seasonal reconstructions of LGM SSTs
obtained with this multi-proxy panel are discussed jointly with model
outputs in order to contribute to ongoing efforts in model-data comparison. |
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