Effects in the radiation belts caused by the second adiabatic invariant violation in the presence of dayside off-equatorial magnetic field minima Original Research Article

Recent experiments (INTERBALL, POLAR) provided new substantial information concerning particle populations in the high-latitude near-magnetopause cusp regions with highly depressed magnetic field. We have studied adiabaticity violation of energetic particle bounce motion in those regions, which is due to nonmonotonous change in magnetic field intensity along field lines near the dayside magnetopause. The violation takes place at the separatrix dividing a region of transequatorial bounce oscillations from that of oscillations about high-latitude field minima. An invariant ‘jump’ is evaluated. Diffusion over the second invariant associated with that jump can result in particle phase space redistribution during magnetic storms.