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| Titel |
Ocean currents generate large footprints in marine palaeoclimate proxies |
| VerfasserIn |
Erik van Sebille, Paolo Scussolini, Jonathan Durgadoo, Frank Peeters, Arne Biastoch, Wilbert Weijer, Chris Turney, Claire Paris, Rainer Zahn |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250103655
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| Publikation (Nr.) |
 EGU/EGU2015-3070.pdf |
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| Zusammenfassung |
| Fossils of marine organisms like planktic foraminifera found in ocean sediments are one of
the cornerstones of palaeoclimatological studies. An underlying assumption in their
interpretation is that foraminiferal shells – and signals derived from these – are
representative of water properties overlying the location of their deposition. Planktic
foraminifera, however, are carried by ocean currents. Depending on the species,
they grow their shell over weeks to months, with the potential to incorporate ocean
conditions from far away. Here, we use high-resolution ocean circulation models to
assess the footprint of planktic foraminifera. We validate our method with proxy
analyses from two sediment cores. Our results show that the palaeoclimatic signal
derived from foraminifera may originate from areas up to several thousands of
kilometers away. Temperature reconstructions derived from proxy records therefore may
represent distant conditions, often significantly different from those at the site. In the
eastern equatorial regions and extensions of the western boundary currents, this
difference may add up to 1.5°C for species living for a month, and up to 3.0°C for
longer-living species. Consideration of the full-lifespan foraminiferal core footprint
and oceanic transport appear crucial aspects in the interpretation of proxy signals. |
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