Article Type:
Research Article

On the Variability of the Thermohaline Circulation in the GFDL Coupled Model

Andrew J. Weaver School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada

Search for other papers by Andrew J. Weaver in
Current site
Google Scholar
PubMed Close
and
Sophie Valcke School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada

Search for other papers by Sophie Valcke in
Current site
Google Scholar
PubMed Close
Print Publication:
01 Apr 1998
DOI:
https://doi.org/10.1175/1520-0442(1998)011<0759:OTVOTT>2.0.CO;2
Page(s):
759–767
Restricted access

Abstract

The ocean component of the Geophysical Fluid Dynamics Laboratory coupled model is used to investigate whether or not the interdecadal variability found in Delworth et al. is an ocean-only mode or a mode of the full coupled system. In particular, it has been previously suggested that the variability in the full coupled model is either 1) an internal ocean mode driven by fixed fluxes (atmospheric annual mean plus flux adjustment), which is made less regular through forcing from atmospheric noise; 2) a consequence of the use of flux adjustments; or 3) an ocean-only mode that is excited by atmospheric noise. Through a series of experiments conducted under fixed-flux boundary conditions it is shown that none of these three hypotheses holds and therefore it is concluded that the interdecadal variability found in Delworth et al. is a mode of the full coupled system.

Corresponding author address: Dr. Andrew J. Weaver, School of Earth and Ocean Sciences, University of Victoria, P.O. Box 3055, Victoria, BC V8W 3P6, Canada

Abstract

The ocean component of the Geophysical Fluid Dynamics Laboratory coupled model is used to investigate whether or not the interdecadal variability found in Delworth et al. is an ocean-only mode or a mode of the full coupled system. In particular, it has been previously suggested that the variability in the full coupled model is either 1) an internal ocean mode driven by fixed fluxes (atmospheric annual mean plus flux adjustment), which is made less regular through forcing from atmospheric noise; 2) a consequence of the use of flux adjustments; or 3) an ocean-only mode that is excited by atmospheric noise. Through a series of experiments conducted under fixed-flux boundary conditions it is shown that none of these three hypotheses holds and therefore it is concluded that the interdecadal variability found in Delworth et al. is a mode of the full coupled system.

Corresponding author address: Dr. Andrew J. Weaver, School of Earth and Ocean Sciences, University of Victoria, P.O. Box 3055, Victoria, BC V8W 3P6, Canada

Save
Cover Journal of Climate
Journal of Climate

  • Bryan, K., 1984: Accelerating the convergence to equilibrium of ocean-climate models. J. Phys. Oceanogr.,14, 666–673.

  • ——, S. Manabe, and R. C. Pacanowski, 1975: A global ocean-atmosphere climate model. Part II: The oceanic circulation. J. Phys. Oceanogr.,5, 30–46.

  • Chen, F., and M. Ghil, 1995: Interdecadal variability of the thermohaline circulation and high-latitude surface fluxes. J. Phys. Oceanogr.,25, 2547–2568.

  • Delworth, T., S. Manabe, and R. J. Stouffer, 1993: Interdecadal variations of the thermohaline circulation in a coupled ocean-atmosphere model. J. Climate,6, 1993–2011.

  • ——, ——, and ——, 1997: Multidecadal climate variability in the Greenland Sea and surrounding regions: A coupled model simulation. Geophys. Res. Lett.,24, 257–260.

  • Greatbatch, R. J., and S. Zhang, 1995: An interdecadal oscillation in an idealized ocean basin forced by constant heat flux. J. Climate,8, 81–91.

  • ——, and K. A. Peterson, 1996: Interdecadal variability and oceanic thermohaline adjustment. J. Geophys. Res.,101 (C9), 20 467–20 482.

  • Griffies, S. M., and E. Tziperman, 1995: A linear thermohaline oscillator driven by stochastic atmospheric forcing. J. Climate,8,2440–2453.

  • Grötzner, A., M. Latif, and T. P. Barnett, 1998: A decadal climate cycle in the North Atlantic Ocean as simulated by the ECHO coupled GCM. J. Climate, in press.

  • Latif, M., and T. P. Barnett, 1994: Causes of decadal climate variability over the North Pacific and North America. Science,266,634–637.

  • Manabe, S., K. Bryan, and M. J. Spelman, 1975: A global ocean-atmosphere climate model. Part I: The atmospheric circulation. J. Phys. Oceanogr.,5, 3–29.

  • ——, R. J. Stouffer, M. J. Spelman, and K. Bryan, 1991: Transient responses of a coupled ocean-atmosphere model to gradual changes of atmospheric CO2. Part I: Annual mean response. J. Climate,4, 785–818.

  • Mikolajewicz, U., and E. Maier-Reimer, 1990: Internal secular variability in an ocean general circulation model. Climate Dyn.,4,145–156.

  • Power, S. B., and R. Kleeman, 1993: Multiple equilibria in a global ocean general circulation model. J. Phys. Oceanogr.,23, 1670–1681.

  • Press, W. H., S. A. Teukolsky, W. T. Vetterling, and B. P. Flannery, 1992: Numerical Recipes in Fortran: The Art of Scientific Computing. 2d ed. Cambridge University Press, 963 pp.

  • Timmermann, A., M. Latif, R. Voss, and A. Grötzner, 1998: Northern Hemispheric interdecadal variability: A coupled air–sea mode. J. Climate, in press.

  • Weaver, A. J., and E. S. Sarachik, 1991: Evidence for decadal variability in an ocean general circulation model: An advective mechanism. Atmos.–Ocean,29, 197–231.

  • ——, J. Marotzke, P. F. Cummins, and E. S. Sarachik, 1993: Stability and variability of the thermohaline circulation. J. Phys. Oceanogr.,23, 39–60.

  • ——, S. M. Aura, and P. G. Myers, 1994: Interdecadal variability in a coarse resolution North Atlantic model. J. Geophys Res.,99,12 423–12 441.

  • Weisse, R., U. Mikolajewicz, and E. Maier-Reimer, 1994: Decadal variability of the North Atlantic in an ocean general circulation model. J. Geophys. Res.,99 (C6), 12 411–12 421.

  • Wohlleben, T. M. H., and A. J. Weaver, 1995: Interdecadal climate variability in the sub-polar North Atlantic. Climate Dyn.,11,459–467.

  • Yang, J., and J. D. Neelin, 1993: Sea-ice interaction with the thermohaline circulation. Geophys. Res. Lett.,20, 217–220.

  • —— and ——, 1997: Decadal variability in coupled sea–ice thermohaline circulation systems. J. Climate,10, 3059–3076.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 410 221 7
PDF Downloads 67 21 1