Using Monte Carlo Simulation to Study the Pile-up Effect of CME and CIR-driven Shocks

This study employs the Monte Carlo simulation method to investigate the shock stacking effect driven by coronal mass ejections (CMEs) and corotating interaction regions (CIRs). First, a probability distribution model incorporating characteristic parameters of CMEs and CIRs—such as velocity, density, and magnetic field—was constructed to reflect their stochasticity and diversity in solar activities. Monte Carlo simulations was performed on one of randomly generated CME and CIR events to track the formation, propagation, and interaction processes of shocks. The simulation results revealed the conditions and influencing factors for shock stacking, demonstrating that the high-speed and high-density characteristics of CMEs, as well as the relative positions and time intervals between CIRs and CMEs, significantly affect the intensity and occurrence probability of the shock stacking effect. Further analysis examined the impact of shock stacking on Earth’s space environment, including compression of the magnetosphere and acceleration of high-energy particles. This study provides critical theoretical foundations and numerical simulation support for understanding solar wind-magnetosphere interactions and space weather forecasting.