Historically, it has been assumed that all solar wind particles are specularly reflected off of the magnetopause. However, because the presence of solar wind plasma is required for the maintenance of many features observed in the ground state magnetosphere, several mechanisms for the transport of energy, mass and momentum through a closed magnetopause have been postulated. In this paper, the consequences of the gradient drift entry (GDE) of charged particles into the magnetosphere are examined qualitatively. It occurs even for particles with solar wind energies because the geomagnetic field at the magnetopause is not precisely uniform and a portion of the incident charged particles are in reality not specularly reflected. This process (which is a direct consequence of particle interactions with a realistically nonuniform geomagnetic field) will, if allowed to operate unimpeded, immediately produce large charge excesses over certain regions of the magnetopause since the GDE process allows only one charge species (either positive ions or electrons) entry to the magnetosphere at a given location.

In this paper we attempt to take the first qualitative steps toward a model that will quantitatively and self-consistently explain the responses of the magnetosphere that may act to limit this charge buildup. Qualitatively, we find the following: (1) the GDE process operates at all times. (2) It provides magnetosheath plasma directly to the equatorial flanks of tail and to the high latitude dayside magnetosphere. (3) This process produces a buildup of excess charge along the flanks of the tail. (4) The direction of current flow in the magnetosphere (to partially dissipate this charge buildup) is always in agreement with observations: dawn to dusk across the tail; along magnetic field lines toward (away from) the ionosphere in the dawn (dusk) hemisphere; and dusk to dawn over the tail lobes. (5) Since the magnetospheric response is not expected to completely get ride of the continuously formed charge buildup, in the steady state electrostatic fields will remain. Their direction is also as observed; Dawn to dusk across the tail; dawn to dusk across the polar cap; and dusk to dawn across the low latitude boundary layer. Basically, we find qualitatively that (other than the formation of the magnetopause by the majority of incident solar wind particles which are reflected) many steady state features and processes (plasmas, electric currents and fields) are formed in the magnetosphere in response to the regions of charge excess produced by the gradient drift entry process. The locations and directions of these plasmas, electric currents and fields are all in agreement with those observed in the magnetosphere. Work is in progress on the further definition of this model with emphasis on a quantitative self-consistent description of the impact of the GDE process on the tail of the magnetosphere.