Local Cosmic Ray Anisotropy Induced by Interplanetary Magnetic Flux Ropes

In this investigation, we present a comprehensive analysis of local cosmic-ray anisotropies induced by interplanetary magnetic flux ropes (MFRs). Utilising observational data, theoretical frameworks, and simulation analyses, we explore the modulation of galactic cosmic rays (GCRs) in relation to the MFR characteristics. The well-structured MFR magnetic field can act like a Lorentz accelerator channelling GCRs along its axial direction. Our study identifies 96 significant MFR events over nearly three decades, revealing a strong correlation between the peak magnetic field intensity and enhancements in GCR flux. Simulations demonstrate that both the strength of the magnetic field and the size of the MFR are crucial for guiding high-energy particles along the MFR axis. These findings challenge the conventional understanding of coronal mass ejections (CMEs) as barriers to cosmic rays, suggesting that MFRs can also serve as channels for GCRs, leading to localized anisotropies in cosmic-ray intensity. The implications of this research extend to astronaut safety and the modeling of cosmic ray behavior in space weather studies.