A Study of Cosmic Ray Variability During a Solar Magnetic Cycle (Solar Cycles 23 and 24)

We investigated variations in Cosmic Ray (CR) intensities during Solar Cycles (SC) 23 and 24. Using data from the Mexico neutron monitor, solar wind parameters (speed, temperature, plasma density), geomagnetic indices (Kp, Dst, ap) from OMNI, and sunspot numbers from SISLO, we analyzed CR intensities during the ascending (ASC) and declining (DSC) phases of each cycle. Our analysis, using distribution plots and regression methods, showed higher CR intensities during the DSC phases compared to the ASC phases for both cycles. Additionally, average CR values were higher during SC 24 than SC 23. These variations are linked to differences in sunspot numbers, solar wind parameters, and geomagnetic indices, differences in magnetic transport across the Sun differ between the ASC and DSC phases, with SC 24 exhibiting weaker meridional flow compared to SC 23. In summary, we find that for the complete Hale cycle we describe, the CR intensities are modulated to different extents during different solar cycle phases and that the modulation varies from one solar cycle to another.