Millennial‐scale variability in the oceans: an ocean modelling view

Abstract Climate and ocean‐only models have shown that the ocean will respond abruptly to significant perturbations in surface forcing. Centennial‐scale oscillation is a characteristic of circulation in large semi‐enclosed ocean basins such as the Arctic, whereas millennial‐scale adjustment to chang...

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Bibliographic Details
Published in:Journal of Quaternary Science
Main Authors: Bigg, Grant R., Wadley, Martin R.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2001
Subjects:
Online Access:http://dx.doi.org/10.1002/jqs.599
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1002%2Fjqs.599
https://onlinelibrary.wiley.com/doi/pdf/10.1002/jqs.599
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Summary:Abstract Climate and ocean‐only models have shown that the ocean will respond abruptly to significant perturbations in surface forcing. Centennial‐scale oscillation is a characteristic of circulation in large semi‐enclosed ocean basins such as the Arctic, whereas millennial‐scale adjustment to changes in surface forcing has been found in the global ocean component of climate models. We show that the millennial time‐scale in climate models is likely to be intrinsic to the ocean through its presence in an ocean‐only model. The strength of the thermohaline circulation is shown to be very sensitive to the magnitude of ice albedo and, to a lesser extent, perturbation in the surface freshwater flux. Modelled glacial ocean circulation, in contrast to present‐day simulations, requires an enhanced freshwater flux over the northern Atlantic, even in its non‐Heinrich state, to obtain realistic overturning in the North Atlantic. Copyright © 2001 John Wiley & Sons, Ltd.