The symmetry properties of planetary magnetic fields

Journal Article · Thu Mar 01 00:00:00 EST 1990 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/JA095iA03p02311· OSTI ID:5256816

Raedler, K H ^[1]; Ness, N F ^[2]

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1. Zentral Inst. fuer Astrophysik, Potsdam-Babelsberg (East Germany)
2. Univ. of Delaware, Newark (United States)

This paper provides a comparative study of the geometrical structures of the magnetic fields of Earth, Jupiter, Saturn, and Uranus, starting from the traditional multipolar representations of these fields. For Earth, Jupiter, and Saturn the centered dipole, quadrupole, and octupole contributions are included, while at Uranus, only the dipole and quadrupole contributoins are considered. The magnetic fields are analyzed by decomposing them into those parts which have simple symmetry properties with respect to the rotation axis and the equatorial plane. It is found that there are a number of common features of the magnetic fields of Earth and Jupiter. Compared to Earth and Jupiter, the Saturnian field exhibits not only a high degree of symmetry about the rotation axis, by now rather well known, but also a high degree of antisymmetry about the equatorial plane. The Uranian field shows strong deviations from both such symmetries. Nevertheless, there remain features common to all four planets. The implications of these results for dynamo models are discussed. With a vgiew to Cowling's theorem the symmetry of the fields is investigated with respect to not only the rotation axis but also to other axes intersecting the plaentary center. Surprisingly, the high degree of asymmetry of the Uranian field that is observed with respect to the rotation axis reduces considerably to being compare to that for Earth or Jupiter when the appropriate axis is employed.

• OSTI ID: 5256816
• Journal Information: Journal of Geophysical Research; (United States), Vol. 95:A3; ISSN 0148-0227
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EARTH PLANET
MAGNETIC FIELDS
JUPITER PLANET
SATURN PLANET
URANUS PLANET
COMPARATIVE EVALUATIONS
MATHEMATICAL MODELS
ROTATION
SYMMETRY
VOYAGER SPACE PROBES
EVALUATION
MOTION
PLANETS
SPACE VEHICLES
VEHICLES
640107* - Astrophysics & Cosmology- Planetary Phenomena