  In a series of earlier papers, we have developed expressions for ion and
electron velocity distribution functions and theirvelocity moments at the
passage over the solar wind termination shock. As we have shown there, with
introduction of appropriate particle invariants and the use of Liouville`s
theorem one can get explicit solutions for the resulting total downstream
pressure adding up from partial pressure contributions of solar wind protons,
solar wind electrons and pick-up protons. These expressions deliver in a first
step the main contributions to the total plasma pressure in the downstream
plasma flow and consistently determine the shock compression ratio. Here now we
start out from these individual fluid pressures downstream of the shock and
thereafter evaluate for the first time the shock-induced entropy production of
the different fluids, when they are passing over the shock to the downstream
side. As is shown here, the resulting ion entropy production substantially
deviates from earlier calculations using a pseudo-polytropic reaction of the
ions to the shock compression, with polytropies selected to describe
fluid-specific reactions at the shock passage similar to those seen by the
VOYAGERs. From these latter models ion entropy jumps are derived that depend on
the pick-up ion abundance, while our calculations, to the opposite, deliver an
abundance-independent ion entropy production which only depends on the shock
compression ratio and the tilt angle between the upstream magnetic field and
the shock surface normal. We also do show here that only when including the
strongly heated electrons into the entropy balance one then arrives at the
total entropy production that just fulfills the thermodynamically permitted
limit.
