Strong pitch-angle diffusion of ring current ions in geomagnetic storm-associated conditions

Do electromagnetic ion cyclotron waves cause strong pitch-angle diffusion of the ring current (RC) ions? This question is the primary motivation of this paper and has been affirmatively answered from the theoretical point of view. The materials that are presented in the Results section show clear evidence that strong pitch-angle diffusion takes place in the inner magnetosphere indicating an important role of the wave–particle interaction in the magnetospheric RC formation.