Influence of the opening of the Drake Passage on the Cenozoic Antarctic Ice Sheet: A modeling approach

We evaluate the opening of the Drake Passage (DP), between Antarctica and South America, and associated changes in ocean circulation as forcing factor for the onset of Antarctic glaciation near the Eocene–Oligocene transition (~ 34 million years ago). In this paper this hypothesis is tested through...

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Bibliographic Details
Published in:Palaeogeography, Palaeoclimatology, Palaeoecology
Main Authors: Cristini, Luisa, Grosfeld, Klaus, Butzin, Martin, Lohmann, Gerrit
Format: Article in Journal/Newspaper
Language:unknown
Published: Elsevier 2012
Subjects:
Online Access:https://epic.awi.de/id/eprint/31232/
http://www.sciencedirect.com/science/article/pii/S0031018212002271
https://hdl.handle.net/10013/epic.40054
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Summary:We evaluate the opening of the Drake Passage (DP), between Antarctica and South America, and associated changes in ocean circulation as forcing factor for the onset of Antarctic glaciation near the Eocene–Oligocene transition (~ 34 million years ago). In this paper this hypothesis is tested through sensitivity experiments, using numerical models for the global ocean and atmosphere and for the Antarctic Ice Sheet. The response of the Antarctic continent to the opening of the DP and to the establishment of the Antarctic Circumpolar Current is examined. Two different climate states are reproduced with ocean gateway configurations similar to the Late Eocene and to the Late Oligocene, before and after the opening of the DP. A reduced southward heat flux and a decrease of surface temperature are found in the Antarctic realm when the DP is open. A more massive ice sheet develops on the continent in case of DP open compared to the configuration with closed DP.