Vol. 7, Issue 2, Part E (2025)

The primary objective of the present study is to investigate the relationship among Cosmic ray Intensity (CRI), Interplanetary Magnetic Field (IMF) and Geomagnetic Storm (GS) for Solar Cycles (SC) 24 and the ascending phase of SC 25 (2008-2023). We also study the role of the southward IMF component Bz in enhancing geomagnetic activities. This study is important because it provides knowledge about how solar and space weather conditions influence the near-Earth environment. Our study revealed that the strongest decrease in CRI value coincides with IMF maxima. When we study the variation in the CRI with the GS we found that the strongest decrease in the CRI value is the same as that of the Disturbance storm time (Dst) index i.e., both achieve their minima on same day, which is probably due to interaction of solar wind energy with the Earth’s magnetic field, which sweeps the cosmic energetic particles, resulting in a decrease in the CRI value. We also noted two types of decreases in the CRI: i) symmetric decrease and ii) asymmetric decreases. The correlation coefficient between the IMF and Dst is (-0.6) and for most of the year, the IMF achieve its maximum value corresponding to minimum value of Dst, this is due to the interconnect of the southward component of the IMF with the Earth’s magnetic field, which allows energy to enter the Earth magnetosphere because geomagnetic activity intensifies and produces geomagnetic storms near the Earth’s surface. Based on our study we conclude that IMF is a good parameter for producing both Geomagnetic Storm and Forbush decrease.