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The sensitivity of convection from a horizontal boundary to the distribution of heating

Published online by Cambridge University Press:  18 March 2010

M. A. COMAN
Affiliation:
Research School of Earth Sciences, The Australian National University, Canberra, ACT 0200, Australia
R. W. GRIFFITHS*
Affiliation:
Research School of Earth Sciences, The Australian National University, Canberra, ACT 0200, Australia
G. O. HUGHES
Affiliation:
Research School of Earth Sciences, The Australian National University, Canberra, ACT 0200, Australia
*
Email address for correspondence: Ross.Griffiths@anu.edu.au

Abstract

Results of experimental and numerical studies are presented for a class of horizontal thermal convection in a long box forced at one horizontal boundary by two regions of destabilizing buoyancy flux separated by a region of stabilizing buoyancy flux. The steady-state circulation with zero net heat input is examined. The circulation generally involves two plumes, one at each end of the box, which drive overturning throughout the domain. The flow is classified into three regimes according to the pattern of interior circulation and depending on the relative heat input applied to the two destabilizing regions. Unequal heat inputs can double the interior stratification above that created by symmetric flow with two identical plumes, and when the heat inputs differ by more than 10%, the interior stratification is set by the stronger plume. The arrangement of boundary forcing broadly parallels the distribution of the zonally averaged surface cooling and heating in the Northern and Southern Hemispheres, and the results suggest that ocean overturning circulations may be sensitive to interhemispheric differences in the buoyancy inputs.

Type
Papers
Copyright
Copyright © Cambridge University Press 2010

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References

REFERENCES

Griffiths, R. W. & Bidokhti, A. A. 2008 Interleaving intrusions produced by internal waves: a laboratory experiment. J. Fluid. Mech. 602, 219239.CrossRefGoogle Scholar
Hughes, G. O. & Griffiths, R. W. 2006 A simple convective model of the global overturning circulation, including effects of entrainment into sinking regions. Ocean Modelling 12, 4679.Google Scholar
Hughes, G. O. & Griffiths, R. W. 2008 Horizontal convection. Annu. Rev. Fluid Mech. 40, 185208.CrossRefGoogle Scholar
Hughes, G. O., Griffiths, R. W., Mullarney, J. C. & Peterson, W. H. 2007 A theoretical model for horizontal convection at high Rayleigh number. J. Fluid. Mech. 581, 251276.CrossRefGoogle Scholar
Mullarney, J. C., Griffiths, R. W. & Hughes, G. O. 2004 Convection driven by differential heating at a horizontal boundary. J. Fluid. Mech. 516, 181209.CrossRefGoogle Scholar
Paparella, F. & Young, W. R. 2002 Horizontal convection is non-turbulent. J. Fluid. Mech. 466, 205214.CrossRefGoogle Scholar
Rossby, H. T. 1965 On thermal convection driven by non-uniform heating from below: an experimental study. Deep Sea Res. 12, 916.Google Scholar
Rossby, H. T. 1998 Numerical experiments with a fluid non-uniformly heated from below. Tellus 50, 242257.CrossRefGoogle Scholar
Schmitz, W. J. 1995 On the interbasin-scale thermohaline circulation. Rev. Geophys. 33, 151173.CrossRefGoogle Scholar
Wang, W. & Huang, R. X. 2005 An experimental study on thermal convection driven by horizontal differential heating. J. Fluid. Mech. 540, 4973.CrossRefGoogle Scholar
Wong, A. B. D. & Griffiths, R. 1999 Stratification and convection produced by multiple plumes. Dyn. Atmos. Oceans 30, 101123.Google Scholar
Wong, A. B. D., Griffiths, R. W. & Hughes, G. O. 2001 Shear layers driven by turbulent plumes. J. Fluid. Mech. 434, 209241.CrossRefGoogle Scholar