Abstract
The scaling law for the strength of planetary magnetic dynamos, originally derived from a magnetohydrodynamic (MHD) theory1, has recently been independently re-derived using simple dimensional analysis2. While dimensional analysis is certainly no replacement for a solution based on a physical mechanism, this analysis does lend more credence to the scaling law by the implicit suggestion that the form of the scaling law is not an artefact of the MHD solution. We show here that the scaling law holds quite well in ordering the three well determined planetary magnetic moments. The present meagre data suggest that the terrestrial magnetic moment is about twice the value expected when compared with the other planets. Assuming that Earth is anomalous, rather than Mercury and Jupiter, and that the scaling law is valid, we predict that Saturn will be found to have a moment of 1.2×1029 G cm3 and Io a moment of 6.5×1022 G cm3.
This is a preview of subscription content, access via your institution
Access options
Subscribe to this journal
Receive 51 print issues and online access
$199.00 per year
only $3.90 per issue
Buy this article
- Purchase on Springer Link
- Instant access to full article PDF
Prices may be subject to local taxes which are calculated during checkout
Similar content being viewed by others
References
Busse, F. H. Phys. Earth planet. Int. 12, 350–358 (1976).
Jacobs, J. Geophys. Res. Lett. 6, 213–214 (1979).
Gubbins, D. Icarus 30, 186–191 (1977).
Siegfried, R. W. & Solomon, S. C. Icarus 23, 192–205 (1974).
Ness, N. F., Behannon, K. W., Lepping, R. P. & Whang, Y. C. Icarus 28, 479–488 (1976).
Jackson, D. J. & Beard, D. B. J. geophys. Res. 82, 2828–2836 (1977).
Whang, Y. C. J. geophys. Res. 82, 1024–1030 (1977).
Russell, C. T., Elphic, R. C. & Slavin, J. A. Science 205, 114–116 (1979).
Gubbins, D. Rev. geophys. Space Phys. 12, 137–154 (1974).
Okal, E. A. & Anderson, D. L. Icarus 33, 514–528 (1978).
Dolginov, Sh. Sh., Yeroshenko, Ye. G. & Zhuzgov, L. N. J. geophys. Res. 81, 3353 (1976).
Russell, C. T. Geophys. Res. Lett. 5, 81–84 (1978).
Stevenson, D. J. & Salpeter, E. E. in Jupiter 85–112 (ed. Gehrels, T.) (University of Arizona Press, 1976).
Davis, L. & Smith, E. J. in Earth's Magnetospheric Particles and Fields, (ed. McCorman, B.) 301 (Reidel, Dordrecht, 1974).
Slattery, W. L. Icarus 32, 58–72 (1977).
Brown, L. W. Astrophys. J. Lett. 198, 189–192 (1975).
Neubauer, F. M. Geophys. Res. Lett. 5, 905–908 (1978).
Kivelson, M. G., Slavin, J. A. & Southwood, D. J. Science 205, 491–493 (1979).
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Russell, C. Scaling law test and two predictions of planetary magnetic moments. Nature 281, 552–553 (1979). https://doi.org/10.1038/281552a0
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/281552a0
This article is cited by
-
Predictions of magnetic fields for Uranus and Neptune
Studia Geophysica et Geodaetica (1986)
-
Geomagnetic reversals and tidal friction
Naturwissenschaften (1981)
Comments
By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.
