OCEAN HEAT TRANSPORT


One of the most important contributions the ocean makes to Earth’s climate is through its poleward heat transport: about 1.5 PW or more than 30% of that accomplished by the ocean-atmosphere system. Recently, concern has arisen over whether global warming could affect this heat transport by, for example, by reducing high latitude convection and triggering a collapse of the deep over turning circulation. While the consequences of abrupt changes in oceanic circulation should be of concern, we argue that the attention devoted to deep circulations is disproportionate to their role in heat transport. For contribution to the heat transport by different components of the oceanic circulation. A new view of the ocean emerges in which a shallow surface intensified circulation dominates the poleward heat transport. this purpose, we introduce a heatfunction which identifies the contribution to the heat transport by different components of the oceanic circulation. A new view of the ocean emerges in which a shallow surface intensified circulation dominates the poleward heat transport.




Figure 1. Streamfunction. Meridional volume transport in Sv (106 m3 /s) inferred from the global circulation model. The streamfunction is equivalent to mass transport as seawater is nearly incompressible. Red shading is clockwise and blue is counter-clockwise flow. Contour interval is 5 Sv. There is substantial mass transport below 500m, associated with deep ocean circulations.
















Figure 2. Heatfunction. Meridional heatfunction in PW (1015 W) inferred from a global circulation model. Red shading is northward heat transport and blue is southward heat transport. Contour interval is 0.17 PW. The bulk of heat is transported within the upper 500 m of the ocean.




















References


Ferrari, R. and D. Ferreira: Pathways of ocean heat transport in a global circulation model, Ocean Modelling, submitted.


Boccaletti G., R. Ferrari, D. Ferreira, A. Adcroft, and J. Marshall, 2005: The vertical structure of the oceanic heat transport, Geophys. Res. Lett., Vol. 32, L10603, 1-4.





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