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:: Subpolar Link to the Emergence of the Modern Equatorial Pacific Cold Tongue
+ 22.06.2010 + The cold upwelling "tongue" of the eastern equatorial Pacific is a central energetic feature of the ocean, dominating both the mean state and temporal variability of climate in the tropics and beyond.
Recent evidence for the development of the modern cold tongue during the Pliocene-Pleistocene transition has been explained as the result of extratropical cooling that drove a shoaling of the thermocline.
We have found that the sub-Antarctic and sub-Arctic regions underwent substantial cooling nearly synchronous to the cold tongue development, thereby providing support for this hypothesis.
In addition, we show that sub-Antarctic climate changed in its response to Earth’s orbital variations, from a subtropical to a subpolar pattern, as expected if cooling shrank the warm-water sphere of the ocean and thus contracted the subtropical gyres.
Alfredo Martínez-Garcia,1,2,3,* Antoni Rosell-Melé,3,4 Erin L. McClymont,5 Rainer Gersonde,6 Gerald H. Haug1,2
1 Geological Institute, ETH Zürich, 8092 Zürich, Switzerland.
2 DFG-Leibniz Center for Surface Process and Climate Studies, Institute for Geosciences, Potsdam University, D-14476 Potsdam, Germany.
3 Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, Bellaterra, 08193 Catalonia, Spain.
4 Institució Catalana de Recerca i Estudis Avançats, Barcelona, 08010 Catalonia, Spain.
5 School of Geography Politics and Sociology, Newcastle University, Newcastle upon Tyne NE1 7RU, UK.
6 Alfred Wegener Institute for Polar and Marine Research, D-27568 Bremerhaven, Germany.
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