The University of Southampton
University of Southampton Institutional Repository

Factors affecting heat transport in an ocean general circulation model

Factors affecting heat transport in an ocean general circulation model
Factors affecting heat transport in an ocean general circulation model
A global ocean general circulation model with idealized geometry and coupled to a simple representation of atmospheric energy fluxes is used to investigate which physical factors determine meridional heat transport. A particular focus is on causes for the common underestimation of heat transport in ocean general circulation models. The model is also forced by an idealized wind stress and moisture flux profiles.
The zonal average of surface heat flux is obtained from a simple radiation parameterization and the divergence of observed atmospheric heat transport. In addition, zonal mixing in the atmosphere is implied by the relaxation of the sea surface temperature (SST) to its zonal average. A finite relaxation timescale results in a substantial increase in the meridional mass overturning in the “Atlantic” basin compared to the case with “infinitely efficient” zonal atmospheric mixing, owing to the admittance of zonal SST gradients. However, heat transport changes only by a small amount. When atmospheric zonal mixing is changed to interbasin mixing, meridional heat transport increases significantly. Doubling the width of the Pacific basin leads to a large increase in the Pacific heat transport, induced by both the meridional overturning and the horizontal gyre circulations.
If the horizontal viscosity is decreased and the zonal resolution is increased near the boundaries, the resulting larger speed of the western boundary currents causes a noticable increase in the Atlantic basin’s heat transport.
The introduction of the Gent–McWilliams eddy parameterization leads to a substantial decrease in the strength of the overturning circulation in the Atlantic basin, presumably because the overall amount of diapycnal mixing is reduced. However, the decrease in the heat transport is much smaller because the thermocline is sharper and the deep ocean colder, resulting in enhanced vertical temperature contrast. Apparent disagreements with and among previous results are explained through the different effects of diapycnal mixing in the North Atlantic and elsewhere in the model.
WOCE, OCEAN CIRCULATION, OCEAN MODELS, HEAT TRANSPORT, SURFACE TEMPERATURE
0022-3670
175-194
Kamenkovich, I.
a859b5f4-be22-4b37-b4c3-9b22e6242a43
Marotzke, J.
6047bfd1-68a3-4abe-95ce-e1df9a56ce76
Stone, P.H.
567e0e57-56ee-4167-b6b5-3d9ffb2a9586
Kamenkovich, I.
a859b5f4-be22-4b37-b4c3-9b22e6242a43
Marotzke, J.
6047bfd1-68a3-4abe-95ce-e1df9a56ce76
Stone, P.H.
567e0e57-56ee-4167-b6b5-3d9ffb2a9586

Kamenkovich, I., Marotzke, J. and Stone, P.H. (2000) Factors affecting heat transport in an ocean general circulation model. Journal of Physical Oceanography, 30 (1), 175-194. (doi:10.1175/1520-0485(2000)030<0175:FAHTIA>2.0.CO;2).

Record type: Article

Abstract

A global ocean general circulation model with idealized geometry and coupled to a simple representation of atmospheric energy fluxes is used to investigate which physical factors determine meridional heat transport. A particular focus is on causes for the common underestimation of heat transport in ocean general circulation models. The model is also forced by an idealized wind stress and moisture flux profiles.
The zonal average of surface heat flux is obtained from a simple radiation parameterization and the divergence of observed atmospheric heat transport. In addition, zonal mixing in the atmosphere is implied by the relaxation of the sea surface temperature (SST) to its zonal average. A finite relaxation timescale results in a substantial increase in the meridional mass overturning in the “Atlantic” basin compared to the case with “infinitely efficient” zonal atmospheric mixing, owing to the admittance of zonal SST gradients. However, heat transport changes only by a small amount. When atmospheric zonal mixing is changed to interbasin mixing, meridional heat transport increases significantly. Doubling the width of the Pacific basin leads to a large increase in the Pacific heat transport, induced by both the meridional overturning and the horizontal gyre circulations.
If the horizontal viscosity is decreased and the zonal resolution is increased near the boundaries, the resulting larger speed of the western boundary currents causes a noticable increase in the Atlantic basin’s heat transport.
The introduction of the Gent–McWilliams eddy parameterization leads to a substantial decrease in the strength of the overturning circulation in the Atlantic basin, presumably because the overall amount of diapycnal mixing is reduced. However, the decrease in the heat transport is much smaller because the thermocline is sharper and the deep ocean colder, resulting in enhanced vertical temperature contrast. Apparent disagreements with and among previous results are explained through the different effects of diapycnal mixing in the North Atlantic and elsewhere in the model.

Full text not available from this repository.

More information

Published date: 2000
Keywords: WOCE, OCEAN CIRCULATION, OCEAN MODELS, HEAT TRANSPORT, SURFACE TEMPERATURE

Identifiers

Local EPrints ID: 8734
URI: https://eprints.soton.ac.uk/id/eprint/8734
ISSN: 0022-3670
PURE UUID: 1d149f8a-991f-4b23-bbbd-9e6caa7ab745

Catalogue record

Date deposited: 14 Sep 2004
Last modified: 17 Jul 2017 17:12

Export record

Altmetrics

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×