Statistical Analysis of the Most Prominent Geo-effective Coronal Mass Ejections Associated with Intense Geomagnetic Storms during Solar Cycle 24

Geomagnetic storms are mostly caused by strong, long-duration, interplanetary magnetic field (IMF B) and southward interplanetary magnetic field (IMF Bz) events. In the present study, a total of 23 intense geomagnetic storms (Dst≤-100 nT) have been found during the period of solar cycle 24 and used to represent the relationship between intense geomagnetic storms and solar activity parameters. One of the main solar phenomena is CMEs, when occurred earth directed, produce geomagnetic storms. It is also observed that these intense geomagnetic storms are associated with disturbances in solar wind plasma parameters. Positive correlation with a correlation coefficient of 0.48 has been found between the magnitude of intense geomagnetic storms and the peak value of IMF(B), 0.37 has been found between the magnitude of intense geomagnetic storms and the magnitude of IMF(B), 0.27 between the magnitude of intense geomagnetic storms and the peak value of associated disturbances in the southward component of IMF (Bz), 0.15 between the magnitude of intense geomagnetic storms and the peak value of southward component of IMF (Bz). Also, we have observed that out of 23 intense geomagnetic storms, 23 are associated with CMEs in which 14 (61%) halo CMEs and 9 (39%) partial halo CMEs occurred.

A main contributor to space weather is geomagnetic storms especially intense ones, which can severely affect ground-based and space-borne technological systems. It is thus important to investigate that the geo-effective causes of storms at the Sun atmosphere. Hence, we conclude that mainly CMEs play a important role for geomagnetic field disturbances.