This session is dedicated to the electromagnetic environment and the physical mechanisms responsible for acceleration, loss, and transport of energetic particles through wave-particle interactions, occurring naturally or triggered by man-made active experiments within geosynchronous orbit. Complexity stems from the variability of the waves/phenomena with (magnetic)-local-time, geomagnetic activity, etc., with a strong dependence on the cold plasma density background. In the near-Earth space, loss driven by wave-particle interactions induces atmospheric precipitation important and hard to predict for its climate impact. Particle injections from substorms and local acceleration from chorus waves occur, competing with and obscuring more gradual processes. All these processes ultimately affect the energetic particle environment near Earth. This session solicits observational studies from one/several satellite/CubeSats missions, ground-based measurements, active experiments, and numerical studies involving particles (electrons/ions/protons) dynamics (transport/loss/acceleration), electromagnetic waves (mapping, growth, properties, effects), wave-particle interactions, large-scale electric/magnetic fields, substorm injections, the plasmasphere, ionospheric effects and atmospheric precipitation.