Distant magnetotails of the outer magnetic planets

Abstract

We assume that the distant planetary magnetotails of Jupiter, Saturn, Uranus, and Neptune are partially open, hot, long plasma cavities generally in pressure equilibrium with the solar wind. Most of the magnetosheath magnetic field lines drape around the magnetotails. We invoke conservation of momentum density, magnetic field, plasma density and energy density fluxes at the tail boundaries to determine the shape of the magnetotails and the variations of plasma and magnetic field characteristics with distance down the magnetotail. We use the Voyager observations to initialize all of our calculations in the near-planet portions of each magnetotail. We present information on estimates of magnetotail cross-sections, magnetic field strengths, and plasma densities as a function of downstream distance. Comparison of our results for Jupiter with the Voyager 2 observations suggests that the model accurately predicts properties of the Jovian magnetotail at least as far as Saturn's orbit.