Sensitive Study of Cosmic Ray Flux Variation with Space Weather and Geomagnetic Disturbances

Driven by the advancements in particle detection technologies, in recent years, there has been a growing interest in using cosmic rays for many practical applications ranging from tomography to space and earth weather monitoring. The challenge in space and earth weather monitoring on a global scale using cosmic rays is to deploy many efficient and affordable detectors that can provide accurate correlations between cosmic ray flux variations and weather conditions. To address this challenge, low-cost and portable muon particle detectors have been developed at Georgia State University as part of the Global Network of Cosmic Ray Detectors for Space and Terrestrial Weather Observation (gLOWCOST). In this study, we aim to determine the correlation and cross-correlation between cosmic ray measurements and the interplanetary solar wind parameter changes at the L1 Lagrange point and geomagnetic indexes. In particular, we have investigated how changes in solar wind plasma, interplanetary magnetic field (IMF) strength, and variations in geomagnetic indices like Kp (planetary index) and Dst (disturbance storm time index) affect cosmic ray (CR) flux at Earth's surface. The results of this analysis show that the muon detectors installed at different geomagnetic cut-off rigidities demonstrate a strong correlation with neutron monitors (NM) and space parameters. All detectors observed a significant flux decrease, i.e., Forbush decrease (FD), during the arrival of interplanetary shocks and geomagnetic storms. Interestingly, for some events, the decrease could be observed several hours before the onset of the first considered interplanetary shocks at L1 driven by the high-speed Coronal Mass Ejection (CME) and related geomagnetic storms (GS). We also determined the time lag over the long term and short term period between cosmic ray flux and changes in solar wind parameters (e.g., IMF, solar wind velocity), Sunspot number (R), and geomagnetic indices (Dst, Kp). The time lag, observed as a delay of 5-10 hours based on preliminary cross-correlation analysis between cosmic ray variability and Dst is important because it suggests that cosmic rays might be able to give us an early warning before geomagnetic storms occur. The findings from this study have the potential to contribute to a better understanding of the interactions between cosmic rays, space parameters, and Earth's atmospheric parameters and gain deeper insight into how cosmic ray flux measurements (muons and neutrons) can be used as predictive indicators for geomagnetic storms.