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| Titel |
The impact of CO2 and ice sheet changes on the temperature evolution during the Middle Miocene climate transition |
| VerfasserIn |
Gregor Knorr, Gerrit Lohmann |
| 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 |
250096991
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| Publikation (Nr.) |
 EGU/EGU2014-12527.pdf |
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| Zusammenfassung |
| About 14 million years ago the middle Miocene climate transition (MMCT) is characterized by the final transition to a large Antarctic ice sheet with an ice volume similar to modern conditions. The overall cooling trend during the MMCT is characterized by multiple alterations of the surface and deep water temperatures associated with e.g. changes in atmospheric CO2 and ice volume changes in Antarctica. During the overall cooling trend marine proxy data from the Southern Ocean reveal a puzzling observation, which is the occurrence of a temperature increase at the ocean surface in the southern high-latitudes at a time of pronounced ice sheet growth in Antarctica and a time delayed response in the deep ocean. With the aid of a comprehensive coupled atmosphere-ocean model we investigate the role of CO2 changes and Antarctic ice sheet growth for the characteristic spatio-temporal surface and deep water temperature evolution during the MMCT. We show that dynamical changes in the coupled atmosphere-ocean-sea ice system in response to ice sheet expansion and a CO2 reduction can explain the observed temperature evolution as recorded in marine proxy data. |
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