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Summary of initial results from the GSFC fluxgate magnetometer on Pioneer 11
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Abstract
The main magnetic field of Jupiter was measured by the Fluxgate Magnetometer on Pioneer 11 and analysis reveals it to be relatively more complex than expected. In a centered spherical harmonic representation with a maximum order of n = 3 (designated GSFC model 04), the dipole term (with opposite polarity to the Earth's) has a moment of 4.28 Gauss x (Jupiter radius cubed), tilted by 9.6 deg towards a system 111 longitude of 232. The quadrupole and octupole moments are significant, 24% and 21% of the dipole moment respectively, and this leads to deviations of the planetary magnetic field from a simple offset tilted dipole for distances smaller than three Jupiter radii. The GSFC model shows a north polar field strength of 14 Gauss and a south polar field strength of 10.4 Gauss. Enhanced absorption effects in the radiation belts may be predicted as a result of field distortion