Bow shock: where the supersonic solar wind abruptly decelerates. Standoff distance ≈ 14 RE upstream in quiet conditions. Drawn in orange.
Magnetopause: the pressure-balance boundary between the magnetosheath and the inner magnetosphere, following the Shue (1997) model r = r0(2/(1+cos φ))α, r0 ≈ 10–12 RE, α ≈ 0.58. Drawn in blue. Particles that reach it are deflected tangentially around Earth instead of passing through.
IMF Bz: raise storm / CME activity to model a southward interplanetary field turning reconnection on — particles begin leaking down the polar cusps and the aurora ovals brighten.