The multifluid character of the solar wind termination shock explaining the downstream supersonic solar wind ion flow

The Voyager-2 observations at the recent crossing of the solar wind termination shock show that the downstream thermal protons still move with supersonic speed. Obviously it is due to their inefficient shock-heating and that the surpathermal ions absorb most of the upstream kinetic solar wind energy. In this paper we present a three-fluid approach of the solar wind plasma consisting of a thermal, a suprathermal and a high-energetic fluid. Within a consistent set of conservation equations for this three-fluid plasma we derive solutions for the observed properties of the upstream precursor and downstream plasma, assuming that the conservation of the magnetic moment of suprathermal ions in the jump conditions is fulfilled.