Whitepaper #131 in the Decadal Survey for Solar and Space Physics (Heliophysics) 2024-2033. Main topics: basic research. Additional topics: space-based missions/projects; system science.
Geospace core plasma supply and refilling (CPSR) are fundamentally important, but fall within a major knowledge gap. Understanding the life cycle of this enormous plasma mass — as important to magnetospheric dynamics as solar-wind driving — has been hindered by the absence of primary cold plasma measurements. This white paper discusses CPSR science gaps and the needed new in-situ/imaging observations.