Fig. 11
Three-layered Earth-ionosphere waveguide model explaining the instantaneous transmission of the electric potential (+V 0) and currents (J xI) given by the downward field-aligned current [FAC(+)] at the left end of the model. The TM0 mode wave consisting of the vertical electric field (E zV) and magnetic field (H yV) perpendicular to the propagation plane propagates at the speed of light, carrying electric currents in the ionosphere and on the ground and transporting the Poynting flux (S xV) consisting of E zV and H yV to low latitude. A fraction of the Poynting flux (S zI = S xV [x + ∆x]−S xV [x]) is transmitted into the ionosphere and another fraction into the inner magnetosphere (S zM). (from Fig. 1 of Kikuchi 2014)