Ionospheric control of space weather
- Office Geophysik, Ogoori, 838-0141, Japan
Abstract. We propose that ionospheric plasma injections to the magnetosphere (ionospheric injection) represent a new plasma process in the polar ionosphere. The ionospheric injection is first triggered by westward electric fields transmitted from the convection surge in the magnetosphere in association with dipolarization onset. Localized westward electric fields result in local accumulation of ionospheric electrons because of differing electron and ion mobility in the E-layer. This charge imbalance was quickly reduced by polarization electric fields generated in the ionosphere. Meanwhile, ion/electron populations are partially released as injections to the magnetosphere to sustain initial potential distributions in quasi-neutral equilibrium.
Resultant geomagnetic field lines are not in equipotential equilibrium during ionospheric injections but instead develop field-aligned potentials to extract ions/electrons ejected from the ionosphere. Field-aligned potential can exist in the magnetic mirror geometry of auroral field lines if the magnetospheric plasma follows quasi-neutral equilibrium. The parallel potential distribution may be global in scale varying monotonically along the field lines between the ionosphere and the equator. Amplified equatorial projection of ionospheric potentials then develop substorm dipolarization processes in a positive feedback loop. Cold plasmas from the ionosphere are distributed along the dynamical trajectories in the magnetosphere and conserve the total energy (including electrostatic potentials) and first adiabatic invariant. They distribute along a dynamical trajectory either leaving only the energetic part of ionospheric plasmas or not changing velocity space distributions from the ionospheric source.
Viewed (geographical distribution)