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An experimental and theoretical investigation of the onset of convection in rotating spherical shells

Published online by Cambridge University Press:  20 April 2006

C. R. Carrigan
Affiliation:
Department of Earth and Space Sciences, Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90024 Permanent address: Sandia National Laboratories, Geophysics Research Division (5541), Albuquerque, NM 87185.
F. H. Busse
Affiliation:
Department of Earth and Space Sciences, Institute of Geophysics and Planetary Physics, University of California, Los Angeles, CA 90024

Abstract

Convection in a rapidly rotating spherical layer with constant-temperature boundary conditions is studied in a laboratory experiment. The asymptotic theory of Busse (1970) is extended to permit a comparison with the observations of the onset of convection and its properties. It is found that the prediction of the power-law dependences of the critical buoyancy number and the critical wavenumber on the rotation rate are borne out, although discrepancies in the actual values of these quantities do exist. Calculations on the basis of equations proposed by Roberts (1968) show that a thermal wind that is present in the basic state of the model has a stabilizing influence on the onset of convection. Stewartson layers not taken into account in the asymptotic analysis for vanishing Ekman number E appear to be responsible for the remaining disagreement between theoretical predictions and observations at finite values of E.

Type
Research Article
Copyright
© 1983 Cambridge University Press

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References

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