Cusp confinement zones on quiet and disturbed dayside magnetosphere

Abstract

The possibility of the charged particle confinement in the dayside regions of magnetosphere cusps is investigated. The analysis, on the basis of Tsyganenko geomagnetic field model, consisted of a numerical simulation of the single charged particle trajectories passing through the regions of the high latitude magnetic field minima. It is shown that the magnetic field topology with off-equatorial field minima itself does not guarantee a particle trap in cusps. In determined conditions relatively stable particle traps exist at different levels of magnetic disturbance, and the topology strongly depends on the seasonal influence. The particles captured in the zones form a kind of cusp radiation belt where particles drift with periods of several minutes conserving the 1st and 2nd adiabatic invariants. This capture and other features of the cusp trapped radiation are discussed.