Geo-Effectiveness of Halo CMEs Based on Magnetic Parameters of the Solar Active Region

While the link between coronal mass ejections (CMEs) and geomagnetic storms has been well established, the prediction of intensity and forecasting of the storms are necessary to notify the adverse effects in advance. In this work, we explore the relationship of the intensity of geomagnetic storm (Dst index) and southward magnetic component (Bs) with the magnetic parameters of the source active region (Space-weather HMI Active Region Patch, SHARP parameters) during 2011‒2017 to find the connection between the magnetic parameters of the source active region and geo-effectiveness. A set of 31 halo CMEs is found to have produced geomagnetic storms from 2011 to 2017. The preliminary analysis shows that these events erupted from active regions with strong and complex magnetic field structures and found to be associated with weak to intense storms (‒6 to ‒223 nT). The following important results are obtained from the detailed analysis: (i) Most of the storms are caused from the events near disk center to western longitudes except three. (ii) Moderate correlations are found between some magnetic parameters of the source active region with the intensity of the storm and southward magnetic field component. (iii) Empirical relations are derived for storm intensity and southward magnetic component in terms of important source region magnetic parameters. Furthermore, we got good correlation for the product of speeds of interplanetary coronal mass ejection (VICME) and Bs with the Dst index. These findings reveal the Sun–Earth connection of certain events and give some clues on improving our ability to connect the intensity of geomagnetic storms with CME kinematics and source region magnetic parameters.