FIELD ALIGNED CURRENT AND PARALLEL ELECTRIC FIELD BETWEEN MAGNETOSPHERE AND IONOSPHERE OF MARS

摘要

A steady state kinetic model is used to estimate the electron current density at different potential differences between the magnetosphere and ionosphere of Mars .For this calculation it is assumed that Mars has a weak dipole magnetosphere whose plasma sheet is connected to the ionosphere along the magnetic field lines. The total electron flux of 5.79×10~8 cm~-2s~-1 is calculated in the Martian magnetosphere corresponding to the downward current density of 1.0×10~-6 A/m~2 at zero potential difference. The maximum flux of thermal electrons escaping towards the plasma sheet of Mars at zero current density is calculated to be 3.0×10~8 cm~-2s~-1. At zero current density the precipitating flux of plasma sheet electrons is approximately equal to maximum escape flux of thermal electrons. The calculated results are found to be in reasonable agreement with the experimental data obtained from Hyperbolic Retarding Potential Analyzer(HARP) experiment onboard Phobos-2.