Ocean heat transport and its relationship to ocean circulation in the CMIP coupled models

The Coupled Model Intercomparison Project was set up to examine climate variability and predictability as simulated by coupled atmosphere-ocean general circulation models, and to evaluate the model results against available observations. This study considers the results from a subproject that concer...

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Bibliographic Details
Main Author: Jia, Y.
Format: Article in Journal/Newspaper
Language:unknown
Published: 2003
Subjects:
Online Access:https://eprints.soton.ac.uk/2138/
http://www.swetswise.com/eAccess/viewAbstract.do?articleID=15534033
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Summary:The Coupled Model Intercomparison Project was set up to examine climate variability and predictability as simulated by coupled atmosphere-ocean general circulation models, and to evaluate the model results against available observations. This study considers the results from a subproject that concerns the ocean heat transport and its relationship to ocean circulation in these coupled models. In particular, the relative roles of the meridional overturning circulation and horizontal circulation in determining the ocean heat transport are assessed and contrasted between the major ocean basins. Many consistent patterns are found among the models and with observations. A number of discrepancies and uncertainties are also identified. Some of the discrepancies have already been seen in ocean only models, and many of the uncertainties are also present in observational studies. In the Atlantic, the meridional overturning circulation that consists of the southward transport of the North Atlantic Deep Water and the northward transport of the upper layer water masses is captured by all the models, and so is the associated northward heat transport, although quantitatively there are large differences. In all the models, the North Atlantic Deep Water is too warm compared with that derived from direct oceanographic measurements, an indication that high-latitude processes responsible for the production and transport of the North Atlantic Deep Water are not well represented. In the Pacific, most of the models produced the upper layer wind-driven circulation. However, none of the models produced a deep circulation pattern close to that deduced from direct oceanographic measurements and consequently the heat transport exhibits large differences between the models. In the Indian Ocean, all models agree on a southward heat transport resulting from a meridional overturning circulation of warm southward flow of upper layer water and cold northward flow of deep water, but disagree on the magnitude of the heat transport and the strength ...