Fig. 4.

Motion of the solar wind H_sw⁺ test particles in the four upstream cases already considered in Fig. 3: (a) the nominal run, (b) the high velocity 2 × U_sw run, (c) the high density 4 × n_sw run and (d) the high density and high IMF 4 × n_sw 2 × IMF run. The trajectories are the same as in Fig. 3 but they are now viewed along the z-axis above the northern hemisphere. The color planes in the z = 0 equator plane indicate the magnitude of the magnetic field. The horizontal and the vertical lengths are each from −10,000 km to 10,000 km.