  In this paper we use three-dimensional electromagnetic particle-in-cell
simulations to investigate the interaction of a small-Larmor radius plasma
cloud/jet with a transverse non-uniform magnetic field typical to a tangential
discontinuity in a parallel geometry. The simulation setup corresponds to an
idealized, yet relevant, magnetospheric configuration likely to be observed at
the magnetopause during northward orientation of the interplanetary magnetic
field. The numerical simulations are adapted to study the kinetic effects and
their role on the transport and entry of localized plasma jets similar to those
identified inside the Earth's magnetosheath propagating towards the
magnetopause. The simulations reveal the formation of a polarization electric
field inside the main bulk of the plasma cloud that enables its forward
transport and entry across the transverse magnetic field. The jet is able to
penetrate the transition region when the height of the magnetic barrier does
not exceed a certain critical threshold. Otherwise, the forward transport along
the injection direction is stopped before full penetration of the magnetopause.
Moreover, the jet is pushed back and simultaneously deflected in the
perpendicular plane to the magnetic field. Our simulations evidence physical
processes advocated previously by the theoretical model of impulsive
penetration and revealed in laboratory experiments.
