Fig. 8

The minimum vertical height, \(H_{\min}\) of oxygen ions (a, d, g, j), protons (b, e, h, k) and electrons (c, f, i, l) above the surface of the Earth as a function of equatorial pitch angle. Here, \(H_{\min}=r_{\min}-R_e\). Each subplot is obtained for the fixed L-shell and four different values of energy. The dashed-dotted black and solid lines represent the theoretical and simulation results, respectively. The vertical dashed line corresponds to the loss cone angle, and the horizontal dashed line represents the upper ionospheric boundary at 1000 km. \(H_{\min}=0\) indicates the surface of the Earth