A three dimensional gasdynamic model for solar wind flow past nonaxisymmetric magnetospheres: Application to Jupiter and Saturn

Journal Article · Sun Oct 01 04:00:00 EDT 1989 · Journal of Geophysical Research; (USA)

DOI:https://doi.org/10.1029/JA094iA10p13353· OSTI ID:5833552

Stahara, S S; Rachiele, R R ^[1]; Spreiter, J R ^[2]; Slavin, J A ^[3]

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1. RMA Aerospace Inc., Mountain View, CA (USA)
2. Stanford Univ., CA (USA)
3. Goddard Space Flight Center, Greenbelt, MD (USA)

The gasdynamic convected magnetic field model for predicting solar wind flow past a planetary magnetoionopause obstacle has been extended to three dimensions to apply to obstacles of nonaxisymmetric shape. The need for such an extension is of first-order importance for Jupiter and Saturn because the effects of rapid spin, large size, and substantial ring current phenomena are believed to cause the magnetospheres of these planets to be significantly broader near the planetary equatorial plane than near the noon-midnight polar meridian plane. Direct observational determination of such asymmetries for Jupiter and Saturn has not been possible, however, because only a limited amount of data are available from four spacecraft at Jupiter and three at Saturn, all of which followed flyby trajectories at fairly low latitudes. With the aid of the new three-dimensional model, it is now possible to infer the degree of flattening of the magnetospheric cross sections from a knowledge of the locations of the low-latitude magnetopause and bow shock crossings. In this paper, the computational procedures of the new model are described, and calculated results are presented for a number of magnetospheres of elliptic cross sections with values ranging from 1 to 2 for the ratio a/b of major (equatorial) to minor (polar) axes. This range is sufficient to include values appropriate to both Jupiter and Saturn. Comparisons of the model results with the locations of observed crossings of the magnetopause and bow shock directly provide an estimate of the degree of equatorial broadening of the magnetospheric cross section for each of these planets.

• OSTI ID: 5833552
• Journal Information: Journal of Geophysical Research; (USA), Journal Name: Journal of Geophysical Research; (USA) Vol. 94:A10; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ASYMMETRY
ATMOSPHERES
CALCULATION METHODS
COMPARATIVE EVALUATIONS
FLUID MECHANICS
HYDRODYNAMICS
INTERACTIONS
JUPITER PLANET
MAGNETOHYDRODYNAMICS
MATHEMATICAL MODELS
MECHANICS
MOTION
PLANETARY ATMOSPHERES
PLANETARY MAGNETOSPHERES
PLANETS
ROTATION
SATURN PLANET
SHOCK WAVES
SOLAR ACTIVITY
SOLAR WIND
THREE-DIMENSIONAL CALCULATIONS