Energetic Particles in the Magnetosphere and their Relationship to Solar Wind Drivers

Enhancements in fluxes of energetic protons, heavy ions and relativistic electrons in planetary environments are initiated by solar and heliospheric processes: (1) directly, as a result of a propagating electromagnetic disturbance which impacts the magnetosphere, modifying the planetary magnetic configuration on the impulse propagation time scale; (2) indirectly, by exciting electromagnetic oscillations in the magnetosphere which diffuse particles across field lines or energize them on given field lines over hours to days. In a magnetized plasma energization of long-term trapped particles is due to a set of different physical processes which violate one or more of the adiabatic invariants. We survey geomagnetic modifications due to solar/heliospheric drivers, geomagnetic eigenoscillations and the mechanisms which break down invariants of trapped particle dynamics, and investigate the resulting effects on observed fluxes. The mechanisms include (a) radial diffusion due to ultra low-frequency (ULF) electromagnetic oscillations and fluctuations in the convection electric field, (b) transittime damping due to fast mode waves, (c) diffusion due to electromagnetic ion-cyclotron or whistler waves and (d) sudden deformation of the magnetic field configuration. The latter can cause trapping of Solar Energetic Particles (SEPs) on a drift time scale to form transient proton and heavy ion belts deep in the magnetosphere (L = 2-3). Radial and energy diffusion time scales become comparable for MeV electrons around the plasmapause (L = 4-5).