  After the termination shock (TS) crossing, the Voyager 2 spacecraft has been
observing strong variations of the magnetic field and solar wind parameters in
the heliosheath. Anomalous cosmic rays, electrons, and galactic cosmic rays
present strong intensity fluctuations. Several works suggested that the
fluctuations might be attributed to spatial variations within the heliosheath.
Additionally, the variability of the solar wind in this region is caused by
different temporal events that occur near the Sun and propagate to the outer
heliosphere. To understand the spatial and temporal effects in the heliosheath,
it is important to study these effects separately. In this work we explore the
role of shocks as one type of temporal effects in the dynamics of the
heliosheath. Although currently plasma in the heliosheath is dominated by solar
minima conditions, with increasing solar cycle shocks associated with
transients will play an important role. We used a 3D MHD multi-fluid model of
the interaction between the solar wind and the local interstellar medium to
study the propagation of a pair of forward-reverse shocks in the supersonic
solar wind, interaction with the TS, and propagation to the heliosheath. We
found that in the supersonic solar wind the interaction region between the
shocks expands, the shocks weaken and decelerate. The fluctuation amplitudes of
the plasma parameters vary with heliocentric distance. The interaction of the
pair of shocks with the TS creates a variety of new waves and discontinuities
in the heliosheath, which produce a highly variable solar wind flow. The
collision of the forward shock with the heliopause causes a reflection of fast
magnetosonic waves inside the heliosheath.
