Understanding energetic particle acceleration and transport is a fundamental challenge in heliophysics because it involves coupling processes across a wide range of scales and environments. Large-scale plasma evolution determines where energy is stored and released and how energetic particles propagate, while kinetic and mesoscale processes govern particle injection, acceleration, and scattering. Energetic particles may also evolve across multiple heliophysical environments rather than remaining tied to a single acceleration site. Particles energized in solar flare regions can propagate through interplanetary space, be reprocessed by CME-driven shocks, and eventually impact near-Earth space weather or the outer heliosphere. Modeling this full chain is difficult because plasma kinetic and global system scales differ by many orders of magnitude, making full kinetic treatments of large 3D systems computationally infeasible. We welcome contributions that connect observations, simulations, and theory to clarify these couplings, identify transferable physics, and distinguish key system-specific differences.

• SM - SPA-Magnetospheric Physics