Effect of Solar and Interplanetary Disturbances on Geomagnetic Field: A Comprehensive Review

The Earth’s geomagnetic field serves as a crucial protective barrier, shielding the planet from the potentially hazardous effects of solar and cosmic radiation. Despite its stabilizing presence, this magnetic shield is highly dynamic and susceptible to disturbances originating from solar and interplanetary phenomena. These disturbances often manifest as geomagnetic storms, which can have serious implications for technological infrastructure, including satellite integrity, communication and navigation systems, and ground-based power grids. This review provides a comprehensive synthesis of historical and contemporary research that explores the intricate pathways through which solar activity particularly Coronal Mass Ejections (CMEs), solar flares, and high-speed solar wind streams interacts with the interplanetary magnetic field (IMF) and subsequently with the Earth’s magnetosphere. Central to this interaction is the process of magnetic reconnection, especially when the IMF exhibits a southward Bz component, which enhances the coupling between solar and terrestrial magnetic fields and triggers energy transfer into the magnetosphere. These interactions are quantitatively assessed using geomagnetic indices such as the Dst (Disturbance Storm Time) index, the Kp index, and the AE (Auroral Electrojet) index, which offer measurable proxies for storm intensity and auroral activity. Furthermore, statistical analyses conducted across solar cycles 24 and 25 have provided critical insights into long term solar-terrestrial dynamics, revealing patterns and thresholds associated with storm onset and severity. The review also highlights the evolution of space weather forecasting methodologies, noting a growing shift towards machine learning and data-driven models that can integrate multi-parametric solar, interplanetary, and geomagnetic data to enhance prediction accuracy. As space weather events pose increasing risks in a technologically dependent world, understanding and forecasting geomagnetic disturbances remain pivotal scientific and operational priorities.