Abstract:       The in-transit ion population in the magnetospheric lobes may play an important role as a seed population for the O+ in the plasmasheet and ultimately in the ring current during active times. It is not clear what is the pathway of ionospheric oxygen to the ring current and what are the mechanisms responsible for their transit from the ionosphere in the time scales observed. A more complete understanding of the nature of this transport mechanism for ions, in particular of O+, is essential to understanding plasmasheet and ring current dynamics. In this talk, I will present a modeling effort based on a 3D MHD global magnetosphere code (LFM), coupled with a guiding center test particle code to explore an O+ activity-dependent transport path from the ionosphere to the plasmasheet and the effects of the O+ in transit between these two regions during transitions from quiet to storm times. I will also present results and updates from other investigations involving radiation belt energetic electron precipitation and its interaction with ULF waves using the same modeling approach. Results indicate that ULF modulation of precipitation occurs even without the presence of VLF-type waves. In addition to that, I will briefly outline future projects involving new numerical modeling approaches.