A conceptual model of core dynamics and the Earth's magnetic field
Article Sidebar
Published:
Feb 27, 1986
Keywords:
Earth core,
Magnetic field of Earth,
External magnetic field,
Dipole field,
Fluid dynamo,
Westward drift of nondipole field
Volumes
Vols. 1-18 (1924-1944), ISSN 0044-2801
Main Article Content
Abstract
A conceptual model of core dynamics and the Earth's magnetic field is presented. It differs from previous investigations in the use of an estimated core viscosity of 2 x 107 cm2 s- 1. The simplified derivations predict the correct order of magnitude for the external magnetic field and for the westward drift of the nondipole field.
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Article Details
How to Cite
Officer, C. (1986). A conceptual model of core dynamics and the Earth’s magnetic field. Journal of Geophysics, 59(1), 89-97. Retrieved from https://journal.geophysicsjournal.com/JofG/article/view/227
Section
References
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Anderson, D.L., Hart, R.S. (1978a) Attenuation models of the Earth. Phys. Earth Planet. Inter. 16:289-306
Anderson, D.L., Hart, R.S. (1978b) Q of the Earth. J. Geophys. Res. 83:5869-5882
Bondi, H., Lyttleton, R.A. (1948) On the dynamical theory of the rotation of the Earth: I, the secular retardation of the core. Proc. Cambridge Philos. Soc. 44:345-359
Braginsky, S.I. (1976) On the nearly axially symmetrical model of the hydromagnetic dynamo of the Earth. Phys. Earth Planet. Inter. 11:191-199
Buchbinder, G.G.R. (1971) A velocity structure of the Earth's core. Bull. Seismol. Soc. Am. 61:429-456
Bukowinski, M.S.T., Knopoff, L. (1976) Electronic structure of iron and models of the Earth's core. Geophys. Res. Lett. 3:45-48
Bullard, E.C. (1948) The secular change in the Earth's magnetic field. Mon. Not. R. Astron. Soc., Geophys. Suppl. 5:248-257
Bullard, E.C. (1949a) The magnetic field within the Earth. Proc. R. Soc. London, Ser. A, 197:433-453
Bullard, E.C. (1949b) Electromagnetic induction in a rotating sphere. Proc. R. Soc. London, Ser. A, 199:413-443
Bullard, E., Gellman, H. (1954) Homogeneous dynamos and terrestrial magnetism. Philos. Trans. R. Soc. London, Ser. A, 247:213-278
Bullard, E.C., Freedman, C., Gellman, H., Nixon, J. (1950) The westward drift of the Earth's magnetic field. Philos. Trans. R. Soc. London, Ser. A, 243:67-92
Busse, F.H. (1975) A model of the geodynamo. Geophys. J. R. Astron. Soc. 42:437-459
Busse, F.H. (1976) Generation of planetary magnetism by convection. Phys. Earth Planet. Inter. 12:350-358
Busse, F.H. (1983) Recent developments in the dynamo theory of planetary magnetism. Annu. Rev. Earth Planet. Sci. 11:241-268
Busse, F.H., Riahi, N. (1980) Nonlinear convection in a layer with nearly insulating boundaries. J. Fluid Mech. 96:243-256
Busse, F.H., Whiteheed, J.A. (1971) Instabilities of convection rolls in a high Prandtl number fluid. J. Fluid Mech. 47:305-320
Elsasser, W.M. (1941) A statistical analysis of the Earth's internal magnetic field. Phys. Rev. 60:876-883
Elsasser, W.M. (1946a) Induction effects in terrestrial magnetism: Part I, theory. Phys. Rev. 69:106-116
Elsasser, W.M. (1946b) Induction effects in terrestrial magnetism: Part II, the secular variation. Phys. Rev. 70:202-212
Elsasser, W.M. (1947) Induction effects m terrestrial magnetism: Part III, electric modes. Phys. Rev. 72:821-833
Elsasser, W.M. (1950) The Earth's interior and geomagnetism. Rev. Mod. Phys. 22:1-35
Elsasser, W.M. (1956) Hydromagnetic dynamo theory. Rev. Mod. Phys. 28:135-163
Gans, R.F. (1972) Viscosity of the Earth's core. J. Geophys. Res. 77:360-366
Gubbins, D. (1974) Theories of the geomagnetic and solar dynamos. Rev. Geophys. Space Phys. 12:137-154
Gubbins, D. (1976) Observational constraints on the generation process of the Earth's magnetic field. Geophys. J. R. Astron. Soc. 47:19-39
Herzenberg, A. (1958) Geomagnetic dynamos. Phil. Trans. R. Soc. London, Ser. A, 250:543-583
Hide, R. (1956) The hydrodynamics of the Earth's core. Phys. Chem. Earth 1:94-137
Hide, R., Roberts, P.H. (1961) The origin of the main geomagnetic field. Phys. Chem. Earth 4:27-98
Howard, L.N. (1966) Convection at high Rayleigh number. Proc. Eleventh Int. Cong. Appl. Math., 1109-1115
Jacobs, J.A. (1975) The Earth's core. Academic Press, London
Jeffreys, H. (1926) The viscosity of the Earth. Mon. Notices Roy. Astron. Soc., Geophys. Suppl. 1:412-424
Jeffreys, H. (1952) The Earth, third edition. Cambridge University Press, London
Krishnamurti, R. (1970a) On the transition to turbulent convection: Part 1, the transition from two to three dimensional flow. J. Fluid Mech. 42:295-307
Krishnamurti, R. (1970b) On the transition to turbulent convection: Part 2, the transition to time dependent flow. J. Fluid Mech. 42:309-320
Krishnamurti, R., Howard, L.N. (1981) Large scale flow generation in turbulent convection. Proc. Natl. Acad. Sci. USA 78:1981-1985
Lamb, H. (1932) Hydrodynamics. Cambridge University Press, London
Levy, E.H. (1972a) Kinematic reversal schemes for the geomagnetic dipole. Astrophys. J. 171:635-642
Levy, E.H. (1972b) On the state of the geomagnetic field and its reversals. Astrophys. J. 175:573-581
Levy, E.H. (1976) Generation of planetary magnetic fields. Annu. Rev. Earth Planet. Sci. 4:159-185
Lorenz, E.N. (1963) Deterministic nonperiodic flow. J. Atmos. Sci. 20:130-141
Merrill, R.T., McElhinny, M.W. (1983) The Earth's magnetic field. Academic Press, London
Moore, D.W., Spiegel, E.A. (1966) A thermally excited nonlinear oscillator. Astrophys. J. 143:871-887
Moore, D.R., Weiss, N.O. (1973) Two dimensional Rayleigh-Benard convection. J. Fluid Mech. 58:389-312
Molodenskiy, S.M. (1981) Upper viscosity boundary of the Earth's core. Izvestiya Earth Phys. 17:903-909
Neild, D.A. (1975) The onset of convective instability. J. Fluid Mech. 71:441-454
Officer, C.B. (1976) Physical oceanography of estuaries. John Wiley, New York
Officer, C.B., Drake, C.L. (1983) Plate dynamics and isostasy in a dynamic system. J. Geophys. 54:1-19
Parker, E.N. (1955) Hydromagnetic dynamo models. Astrophys. J. 122:293-314
Parker, E.N. (1969) The occasional reversal of the geomagnetic field. Astrophys. J. 158:815-827
Qamar, A., Eisenberg, A. (1974) The damping of core waves. J. Geophys. Res. 79:758-765
Rikitake, T. (1966) Electromagnetism and the Earth's interior. Elsevier, Amsterdam
Robbins, K.A. (1976) A moment equation description of magnetic reversals in the Earth. Proc. Natl. Acad. Sci. USA 73:4297-4301
Robbins, K.A. (1977) A new approach to subcritical instability and turbulent transitions in a simple dynamo. Math. Proc. Cambridge Philos. Soc. 82:309-325
Roberts, P.H. (1967) An introduction to magnetohydrodynamics. Longmans, London
Roberts, P.H. (1971) Dynamo theory. In: Reid, W.H. (Ed.) Mathematical problems in the geophysical sciences, II, inverse problems, dynamo theory and tides, pp. 129-206, Providence: American Mathematical Society
Sacks, I.S. (1971) An elasticity of the outer core. In: Annu. Rep. Dep. Terr. Mag. 1969-1970, Carnegie Inst., Washington, pp. 414-426
Sato, R., Espinosa, A.F. (1967) Dissipation in the Earth's mantle and rigidity and viscosity in the Earth's core determined from waves multiply reflected from the mantle-core boundary. Bull. Seismal. Soc. Am. 57:829-856
Soward, A.M. (Ed.) (1982) Stellar and planetary magnetism. Gordon and Breach, New York
Sparrow, C. (1982) The Lorenz equations: Bifurcations, chaos and strange attractors. Springer, Berlin-Heidelberg-New York
Stacey, F.D. (1977) Physics of the Earth. John Wiley, New York
Suzuki, Y., Sato, R. (1970) Viscosity determination in the Earth's outer core from ScS and SKS phases. J. Phys. Earth 18:157-170
Verhoogen, J. (1980) Energetics of the Earth. National Academy of Sciences, Washington
Watanabe, H. (1977) Bounds on the fluid velocity and magnetic field in the Earth's core imposed by hydromagnetic consideration of an ixw-dynamo. J. Geomagn. Geoelectr. 29:191-209
Welander, P. (1967) On the oscillatory instability of a differentially heated fluid loop. J. Fluid Mech. 29:17-30
Anderson, D.L., Hart, R.S. (1978a) Attenuation models of the Earth. Phys. Earth Planet. Inter. 16:289-306
Anderson, D.L., Hart, R.S. (1978b) Q of the Earth. J. Geophys. Res. 83:5869-5882
Bondi, H., Lyttleton, R.A. (1948) On the dynamical theory of the rotation of the Earth: I, the secular retardation of the core. Proc. Cambridge Philos. Soc. 44:345-359
Braginsky, S.I. (1976) On the nearly axially symmetrical model of the hydromagnetic dynamo of the Earth. Phys. Earth Planet. Inter. 11:191-199
Buchbinder, G.G.R. (1971) A velocity structure of the Earth's core. Bull. Seismol. Soc. Am. 61:429-456
Bukowinski, M.S.T., Knopoff, L. (1976) Electronic structure of iron and models of the Earth's core. Geophys. Res. Lett. 3:45-48
Bullard, E.C. (1948) The secular change in the Earth's magnetic field. Mon. Not. R. Astron. Soc., Geophys. Suppl. 5:248-257
Bullard, E.C. (1949a) The magnetic field within the Earth. Proc. R. Soc. London, Ser. A, 197:433-453
Bullard, E.C. (1949b) Electromagnetic induction in a rotating sphere. Proc. R. Soc. London, Ser. A, 199:413-443
Bullard, E., Gellman, H. (1954) Homogeneous dynamos and terrestrial magnetism. Philos. Trans. R. Soc. London, Ser. A, 247:213-278
Bullard, E.C., Freedman, C., Gellman, H., Nixon, J. (1950) The westward drift of the Earth's magnetic field. Philos. Trans. R. Soc. London, Ser. A, 243:67-92
Busse, F.H. (1975) A model of the geodynamo. Geophys. J. R. Astron. Soc. 42:437-459
Busse, F.H. (1976) Generation of planetary magnetism by convection. Phys. Earth Planet. Inter. 12:350-358
Busse, F.H. (1983) Recent developments in the dynamo theory of planetary magnetism. Annu. Rev. Earth Planet. Sci. 11:241-268
Busse, F.H., Riahi, N. (1980) Nonlinear convection in a layer with nearly insulating boundaries. J. Fluid Mech. 96:243-256
Busse, F.H., Whiteheed, J.A. (1971) Instabilities of convection rolls in a high Prandtl number fluid. J. Fluid Mech. 47:305-320
Elsasser, W.M. (1941) A statistical analysis of the Earth's internal magnetic field. Phys. Rev. 60:876-883
Elsasser, W.M. (1946a) Induction effects in terrestrial magnetism: Part I, theory. Phys. Rev. 69:106-116
Elsasser, W.M. (1946b) Induction effects in terrestrial magnetism: Part II, the secular variation. Phys. Rev. 70:202-212
Elsasser, W.M. (1947) Induction effects m terrestrial magnetism: Part III, electric modes. Phys. Rev. 72:821-833
Elsasser, W.M. (1950) The Earth's interior and geomagnetism. Rev. Mod. Phys. 22:1-35
Elsasser, W.M. (1956) Hydromagnetic dynamo theory. Rev. Mod. Phys. 28:135-163
Gans, R.F. (1972) Viscosity of the Earth's core. J. Geophys. Res. 77:360-366
Gubbins, D. (1974) Theories of the geomagnetic and solar dynamos. Rev. Geophys. Space Phys. 12:137-154
Gubbins, D. (1976) Observational constraints on the generation process of the Earth's magnetic field. Geophys. J. R. Astron. Soc. 47:19-39
Herzenberg, A. (1958) Geomagnetic dynamos. Phil. Trans. R. Soc. London, Ser. A, 250:543-583
Hide, R. (1956) The hydrodynamics of the Earth's core. Phys. Chem. Earth 1:94-137
Hide, R., Roberts, P.H. (1961) The origin of the main geomagnetic field. Phys. Chem. Earth 4:27-98
Howard, L.N. (1966) Convection at high Rayleigh number. Proc. Eleventh Int. Cong. Appl. Math., 1109-1115
Jacobs, J.A. (1975) The Earth's core. Academic Press, London
Jeffreys, H. (1926) The viscosity of the Earth. Mon. Notices Roy. Astron. Soc., Geophys. Suppl. 1:412-424
Jeffreys, H. (1952) The Earth, third edition. Cambridge University Press, London
Krishnamurti, R. (1970a) On the transition to turbulent convection: Part 1, the transition from two to three dimensional flow. J. Fluid Mech. 42:295-307
Krishnamurti, R. (1970b) On the transition to turbulent convection: Part 2, the transition to time dependent flow. J. Fluid Mech. 42:309-320
Krishnamurti, R., Howard, L.N. (1981) Large scale flow generation in turbulent convection. Proc. Natl. Acad. Sci. USA 78:1981-1985
Lamb, H. (1932) Hydrodynamics. Cambridge University Press, London
Levy, E.H. (1972a) Kinematic reversal schemes for the geomagnetic dipole. Astrophys. J. 171:635-642
Levy, E.H. (1972b) On the state of the geomagnetic field and its reversals. Astrophys. J. 175:573-581
Levy, E.H. (1976) Generation of planetary magnetic fields. Annu. Rev. Earth Planet. Sci. 4:159-185
Lorenz, E.N. (1963) Deterministic nonperiodic flow. J. Atmos. Sci. 20:130-141
Merrill, R.T., McElhinny, M.W. (1983) The Earth's magnetic field. Academic Press, London
Moore, D.W., Spiegel, E.A. (1966) A thermally excited nonlinear oscillator. Astrophys. J. 143:871-887
Moore, D.R., Weiss, N.O. (1973) Two dimensional Rayleigh-Benard convection. J. Fluid Mech. 58:389-312
Molodenskiy, S.M. (1981) Upper viscosity boundary of the Earth's core. Izvestiya Earth Phys. 17:903-909
Neild, D.A. (1975) The onset of convective instability. J. Fluid Mech. 71:441-454
Officer, C.B. (1976) Physical oceanography of estuaries. John Wiley, New York
Officer, C.B., Drake, C.L. (1983) Plate dynamics and isostasy in a dynamic system. J. Geophys. 54:1-19
Parker, E.N. (1955) Hydromagnetic dynamo models. Astrophys. J. 122:293-314
Parker, E.N. (1969) The occasional reversal of the geomagnetic field. Astrophys. J. 158:815-827
Qamar, A., Eisenberg, A. (1974) The damping of core waves. J. Geophys. Res. 79:758-765
Rikitake, T. (1966) Electromagnetism and the Earth's interior. Elsevier, Amsterdam
Robbins, K.A. (1976) A moment equation description of magnetic reversals in the Earth. Proc. Natl. Acad. Sci. USA 73:4297-4301
Robbins, K.A. (1977) A new approach to subcritical instability and turbulent transitions in a simple dynamo. Math. Proc. Cambridge Philos. Soc. 82:309-325
Roberts, P.H. (1967) An introduction to magnetohydrodynamics. Longmans, London
Roberts, P.H. (1971) Dynamo theory. In: Reid, W.H. (Ed.) Mathematical problems in the geophysical sciences, II, inverse problems, dynamo theory and tides, pp. 129-206, Providence: American Mathematical Society
Sacks, I.S. (1971) An elasticity of the outer core. In: Annu. Rep. Dep. Terr. Mag. 1969-1970, Carnegie Inst., Washington, pp. 414-426
Sato, R., Espinosa, A.F. (1967) Dissipation in the Earth's mantle and rigidity and viscosity in the Earth's core determined from waves multiply reflected from the mantle-core boundary. Bull. Seismal. Soc. Am. 57:829-856
Soward, A.M. (Ed.) (1982) Stellar and planetary magnetism. Gordon and Breach, New York
Sparrow, C. (1982) The Lorenz equations: Bifurcations, chaos and strange attractors. Springer, Berlin-Heidelberg-New York
Stacey, F.D. (1977) Physics of the Earth. John Wiley, New York
Suzuki, Y., Sato, R. (1970) Viscosity determination in the Earth's outer core from ScS and SKS phases. J. Phys. Earth 18:157-170
Verhoogen, J. (1980) Energetics of the Earth. National Academy of Sciences, Washington
Watanabe, H. (1977) Bounds on the fluid velocity and magnetic field in the Earth's core imposed by hydromagnetic consideration of an ixw-dynamo. J. Geomagn. Geoelectr. 29:191-209
Welander, P. (1967) On the oscillatory instability of a differentially heated fluid loop. J. Fluid Mech. 29:17-30