  Measurements made with the Voyager 1 spacecraft indicate that significant
levels of compressive fluctuations exist in the inner heliosheath. Some studies
have already been performed with respect to the mirror-mode instability in the
downstream region close to the solar wind termination shock, and here we extend
the investigation to the whole inner heliosheath. We employ quasilinear theory
and results from a global magnetohydrodynamic model of the heliosphere to
compute the time evolution of both the temperature anisotropy and the energy
density of the corresponding magnetic fluctuations, and we demonstrate their
likely presence in the inner heliosheath. Furthermore, we compute the
associated, locally generated density fluctuations. The results can serve as
inputs for future models of the transport of compressible turbulence in the
inner heliosheath.
