Impact of Ionospheric Ions on Magnetospheric Dynamics

Ionospheric ion outflow changes the magnetospheric dynamics. It is especially important during disturbed magnetospheric conditions. In the inner magnetosphere, it is relevant also during quiet times. The presence of ionospheric ions affects the plasma properties by changing the plasma density, temperature, and pressure. Modified plasma properties then influence the magnitude of Alfvén velocity, affect the structure and dynamics of the current sheet, and, as a result, physical processes such as reconnection, the development of plasma instabilities, and wave generation. On the large scales, the ionospheric ion outflow changes the shape of the magnetosphere and its configuration. Outflow affects substorm-like events, magnetic storms, dynamics of radiation belts, and magnetosphere- ionosphere-ring current coupling. In this chapter, we introduce the circulation of ionospheric ions and then discuss the effects mentioned above in detail. We pose questions for future research.