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| Titel |
The role of ocean gateways on cooling climate on long time scales |
| VerfasserIn |
Willem Sijp, Henk Dijkstra, Anna von der Heydt, Sascha Floegel |
| Konferenz |
EGU General Assembly 2014
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 16 (2014) |
| Datensatznummer |
250090612
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| Publikation (Nr.) |
 EGU/EGU2014-4869.pdf |
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| Zusammenfassung |
| We examine ocean changes in response to changes in paleogeography from the Cretaceous to
present in an intermediate complexity model and in the fully coupled CCSM3 model.
Greenhouse gas concentrations are kept constant to allow a focus on effects arising from
changing continental configurations. We find consistent and significant geography-related
Cenozoic cooling arising from the opening of Southern Ocean (SO) gateways. Both models
exhibit consistent behaviour, with a 6° C deep ocean cooling arising from tectonic
evolution alone. Simulations employing continental configurations associated with
greenhouse climates, namely the Turonian and the Eocene simulations, systematically
exhibit warm deep ocean temperatures at elevated pCO2 close to 10 ° C. In contrast,
continental configurations associated with (later) icehouse climates are associated
with cooler deep ocean temperatures at identical pCO2, arising from a progressive
maturation of the ACC. This suggests that a component of the Cenozoic benthic cooling
trend recorded in oxygen isotopes could arise directly from changes in continental
configuration, and so be decoupled to a degree from the Cenozoic greenhouse gas
history. |
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