The different behaviour of modeled ocean circulation under an atmosphere with different heat capacity
- 30 Downloads
We examine the difference in modeled thermohaline circulation under an atmosphere with no heat capacity (NHC) and infinite heat capacity (IHC) in a series of numerical experiments using the Bryan/Cox OGCM. An NHC atmosphere allows ocean sea surface temperatures to respond to changes in oceanic poleward heat transport, inferring an atmosphere that is allowed to seek its equilibrium temperature, whereas an IHC atmosphere does not. This is responsible for the following different behaviour patterns under the two atmospheres: 1) under NHC atmosphere, oceanic thermal oscillation persists, whereas under IHC atmosphere it does not; 2) under NHC atmosphere, the oceanic thermohaline circulation is less sensitive to high latitude freshening than under IHC atmosphere; 3) under either atmosphere, multiple equilibrium solutions are possible. However, under NHC atmosphere, two equilibria of the thermohaline circulation are generated in the same way as in the GFDL fully coupled model, while under IHC atmosphere, they are not.
KeywordsHeat Capacity Heat Transport Equilibrium Solution Behaviour Pattern Equilibrium Temperature
Unable to display preview. Download preview PDF.
- Bretherton, F. P. (1982): Ocean climate modeling. p. 93–129. InProgress in Oceanography, Vol. 11, Pergamon.Google Scholar
- Cox, M. D. (1987):GFDL Ocean Model Circular No. 7. GFDL/Princeton University. Princeton, N.J., 1 pp.Google Scholar
- Fujio, S., T. Kadowaki and N. Imasato (1992): World ocean circulation diagnostically derived from hydrographic and wind stress fields: I. The velocity field.J. Geophys. Res.,97, 11, 163–11, 176.Google Scholar
- Giese, B. S. and D. R. Cayan (1993): Surface heat flux parameterizations and tropical Pacific sea surface temperature simulations.J. Geophys. Res.,98, 6979–6989.Google Scholar
- Pacanowski, R. C., K. W. Dixon and A. Rosati (1991):GFDL Modular Ocean Model, Users Guide Version 1.0, GFDL Ocean Group Tech. Rep. No. 2, 46 pp.Google Scholar
- Philander, S. G. H. and A. D. Seigel (1985): Simulation of El Niño of 1982–83. p. 517–541. InCoupled Ocean-Atmosphere Models, ed. by J. Nihoul, Elsevier, New-York.Google Scholar
- Sarmiento, J. L. and K. Bryan (1982): An ocean transport model for the North Atlantic.J. Geophys. Res.,87, 394–408.Google Scholar
- Seager, R., S. E. Zebiak and M. A. Cane (1988): A model for tropical Pacific sea surface temperature climatology.J. Geophys. Res.,93, 1265–1280.Google Scholar
- Semtner, A. J. and R. M. Chervin (1988): A simulation of the global ocean circulation with resolved eddies.J. Geophys. Res.,93, 15502–15522.Google Scholar
- Stommel, H. (1961): Thermohaline convection with two stable regimes of flow.Tellus,13, 224–230.Google Scholar