Cusp auroral proton precipitation in the simulation with southward IMF. (a) Differential number flux of proton precipitation in the northern cusp, with the mean precipitating energy indicated with a black line. (b) Integral energy flux of proton precipitation in the northern cusp. (c) Same as (a) for the southern cusp. (d) Same as (b) for the southern cusp. The time intervals shaded in grey indicate that the corresponding virtual spacecraft was not magnetically connected to the inner boundary of the simulation.