Authors: Rekha Agarwal, Rajesh Kumar Mishra, Divyansh Mishra
Abstract: Recent solar cycles, particularly the ascending and peak phases of Solar Cycle 25 (2020–2025), have been characterized by heightened solar activity, including X-class flares, fast coronal mass ejections (CMEs), and complex interplanetary shocks. These transient events strongly modulate galactic cosmic rays (GCRs) and produce solar energetic particles (SEPs), thereby altering the flux, energy spectrum, and anisotropy of high-energy charged particles in near-Earth space. This paper synthesizes observational and theoretical advances concerning the effect of recent solar events on high-energy cosmic ray particles (>100 MeV to multi-GeV), with emphasis on Forbush decreases, shock acceleration, magnetic cloud interactions, and ground level enhancements (GLEs). We discuss observations from neutron monitor networks and space-based detectors such as Parker Solar Probe, Solar Orbiter, ACE, and GOES, highlighting case studies from 2021–2024. Quantitative comparisons reveal cosmic ray depressions of 3–20% during major CME passages and episodic enhancements up to GeV energies during extreme SEP events. The broader implications for space weather, atmospheric ionization, and radiation risk are examined.
