Electric field effects on the access of magnetosheath plasma to the distant magnetotail

The field model used in the trajectory calculations of Bird (1974) was based on a self-consistent calculation of the tail magnetic field under very quiet conditions (Bird and Beard, 1972). Only drift and magnetization currents in the plasma sheet and on the tail boundary were considered sources of the observed magnetic field. Recent trajectory calculations by Pudovkin and Tsyganenko (1973) yielded results qualitatively similar to those of Bird (1974), but no analysis of particle access from the magnetosheath was made. Both models assumed the electric field to be zero. A more realistic model, in view of the highly variable solar wind flux, would be to include the possibility of non-vanishing electric fields. The effects of a constant dawn-to-dusk electric field of arbitary strength on the penetration of magnetosheath protons along the down magnetotail flank is investigated in this paper (Auth.)