CME Properties Evolve with Intrinsic Solar Cycle Signatures, Not Just Propagation Speed

This arXiv preprint (not yet peer-reviewed) applies superposed epoch analysis to 1600+ in-situ CME events from the HELIO4CAST catalog spanning 0.2–2.2 au. It reveals that active-phase (AP) CMEs remain faster and magnetically stronger than quiet-phase (QP) events even after speed is controlled for, while QP events show higher density but weaker fields. Toroidal and poloidal magnetic components decay at comparable rates, yet front-to-rear asymmetry grows with distance. Prior work such as Winslow et al. (2015, JGR) documented radial expansion but lacked solar-cycle partitioning; Lugaz et al. (2017, ApJ) noted density variations without isolating eruption physics. The new analysis implies that AP eruptions may launch with different initial flux-rope topologies, a distinction missed in purely kinematic forecasting models. Limitations include reliance on a single catalog, sparse coverage beyond 1 au, and the absence of direct magnetic-helicity measurements. These findings directly refine 12-month space-weather outlooks by showing that solar-cycle phase modulates CME geoeffectiveness beyond speed alone, with consequences for power-grid and GPS resilience planning.