A Study on the Geoeffectiveness of Halo Coronal Mass Ejections During the Period of 1996- 2018

Abstract

In this study, we investigate the solar origins and interplanetary properties of 83 geoeffective halo coronal mass ejections (CMEs) that produced intense geomagnetic storms (Dst ≤ -100 nT) on Earth, spanning the time interval from 1996 to 2018, which includes solar cycles 23 and 24. Observations indicate that full-halo CMEs are potential contributors to intense geomagnetic activity on Earth. However, it is worth noting that not all full-halo CMEs lead to significant geomagnetic storms, which adds complexity to the task of space weather forecasting. Our investigation delves into the solar origins and flare connections of these geoeffective CMEs and their interplanetary effects, specifically, solar wind speed, and the southward component of the interplanetary magnetic field Bz. The objective is to elucidate the relationship between solar and interplanetary parameters. Specifically, this study aims to identify solar parameters that govern key interplanetary parameters responsible for generating significant geomagnetic storms. Our findings indicate that fast full-halo CMEs, associated with powerful flares and originating from favourable locations (i.e., near the central meridian and at low to mid latitudes), are the most likely candidates for producing intense geomagnetic storms. Additionally, our results demonstrate that the intensity of geomagnetic storms is most strongly influenced by the southward component of the interplanetary magnetic field, but is less dependent on the initial speed of the CME.