The main magnetic field of Jupiter

The main magnetic field of Jupiter has been measured by the Goddard Space Flight Center flux gate magnetometer on Pioneer 11, and analysis of the data yields a more detailed model than that obtained from Pioneer 10 results. In a spherical harmonic octupole representation the dipole term (with opposite polarity to earth's) has a magnitude of 4.28 G R/sub j/ 3 at a tilt angle of 9.6degree and a system III longitude of 232degree. The quadrupole and octupole moments are significant, 24% and 21% of the dipole, respectively. This leads to a significant deviation of the planetary magnetic field from a simple offset dipole topology at distances of <3R/sub j/. The north polar field strength is 14 G, and in the northern hemisphere the 'footprint' of the lo associated flux tube traverses the magnetic polar region. Associated L shell splitting in the radiation belts, warping of the charged particle equatorial planes, and enhanced absorption effects due to the satellites Amalthea and lo are expected as a result of the field complexity