  Under quasi-radial interplanetary magnetic fields (IMF), foreshock turbulence
can have an impact on the magnetosheath and cusps depending on the location of
the quasi-parallel shock. We perform three-dimensional simulations of Earth's
dayside magnetosphere using the hybrid code HYPERS, and compare northward and
southward quasi-radial IMF configurations. We study the magnetic field
configuration, fluctuations in the magnetosheath and the plasma in the regions
around the northern cusp. Under northward IMF with Earthward $B_x$, there is a
time-varying plasma depletion layer immediately outside the northern cusp. In
the southward IMF case, the impact of foreshock turbulence and high-speed jets,
together with magnetopause reconnection, can lead to strong density
enhancements in the cusp.
