Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-10T22:29:53.820Z Has data issue: false hasContentIssue false
  • English
  • Français

Mean Electromotive Force Due to Magnetoconvection in Rotating Horizontal Layer in Dependence on Boundary Conditions

Published online by Cambridge University Press:  19 July 2016

J. Brestenský ,
S. Ševčík  and
L. Rosenberg
J. Brestenský
Affiliation:
Department of Geophysics, Faculty of Mathematics and Physics, Comenius University, 84215 Bratislava, CSFR
S. Ševčík
Affiliation:
Department of Geophysics, Faculty of Mathematics and Physics, Comenius University, 84215 Bratislava, CSFR
L. Rosenberg
Affiliation:
Department of Geophysics, Faculty of Mathematics and Physics, Comenius University, 84215 Bratislava, CSFR

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

The instability due to a vertical uniform temperature gradient is studied in a rapidly rotating horizontal layer of an electrically conducting fluid permeated by an azimuthal magnetic field linearly growing with the distance from the vertical axis of rotation. In addition to the boundary conditions used in So ward's study (1979), that is, force-free surface and perfect electrical and thermal conductivity outside, also other conditions more realistic for the Earth's core are considered, that is, rigid surface and electrically insulating walls. Using the concept of meanfield mlid mean electromotive and ponderomotive forces (E.M.F. and P.M.F.) are calculated and compared for various boundary conditions. The dependence of the E.M.F. and P.M.F. on the electromagnetic boundary conditions is strong (slight) if the boundaries are free (rigid).

Keywords

Hydromagnetic instabilitiesmean electromotive forceEarth's core
Type
10. Geodynamo and Planetary Dynamos
Information
Symposium - International Astronomical Union , Volume 157: The Cosmic Dynamo , 1993 , pp. 457 - 461
Copyright
Copyright © Kluwer 1993 

References

Brandenburg, A., Tuominen, I. and Rädler, K.-H.: 1989, GAFD 49, 45–56 Google Scholar
Brestenský, J. and Rädler, K.-H.: 1989, GAFD 49, 57–70 Google Scholar
Brestenský, J.: 1991, in Proceedings of the 2nd Convegno di Geomagnetismo et Aeronomia — 1988, ed(s)., Meloni, A. and Zolesi, B., Istituto Nazionale di Geofisica: Roma, 157–171 Google Scholar
Brestenský, J., Rädler, K.-H. and Fuchs, H.: 1992, unpublished, Google Scholar
Chandrasekhar, S.: 1968, Hydrodynamic and Hydromagnetic Stability , Clarendon Press: Oxford Google Scholar
Krause, F. and Rädler, K.-H.: 1980, Mean-Field Magnetohydrodynamics and Dynamo Theory , Akademie-Verlag: Berlin and Pergamon Press: Oxford Google Scholar
Rüdiger, G.: 1989, Differential Rotation and Stellar Convection , Akademie-Verlag: Berlin and Gordon and Breach Science Publishers: New-York Google Scholar
Soward, A.M.: 1979, ‘Thermal and magnetically driven convection in a rapidly rotating fluid layer’, J. Fluid Mech. 90, 669–684 Google Scholar
Ševčík, S.: 1989, GAFD 49, 195–211 Google Scholar