Inner Magnetosphere

One consequence of space weather is the occurrence of geomagnetic storms at Earth, which manifest themselves through the formation of an intense, westward toroidal electric current that encircles the Earth. This ring current is nominally situated between 2 to 9 Earth radii around the Earth, centered around the magnetic equatorial plane. It is formed through convective transport and magnetic drifts (due to the inhomogeneity in the magnetic field) of trapped particles that move under the influence of the Lorentz force.

Although all trapped particles in the inner magnetosphere contribute to the ring current, the main carriers are positive ions with energies ranging from a few keV to hundreds of keV; electrons contribute only minimallyy because of their small mass and energy densities. The ring current is an intricate and dynamic system whose structure and intensity can change dramatically on many time scales due to disturbances induced by the solar wind. Particle motion can differ greatly for particles of different energies and the coupling between the plasma and fields plays a key role in the overall behavior of ring current system