The influence of solar activity on geomagnetic disturbances over cycles 23 and 24

Abstract

We investigate the relationship between the geomagnetic storms and solar events, building a reliable catalog of multi-geomagnetic storms in a period of August 1996 - December 2019. We analyze the effect of the solar activity on geomagnetic storms and their characteristics from various sources for the solar and solar wind datasets, including the minimum–maximum phases of cycles 23 and 24. Geomagnetic activities are higher in cycle 23 than cycle 24. We ultimately picked up 104 geomagnetic storms resulting from solar and interplanetary space (IP) sources with min-Dst index $⩽$-100 nT. We obtain a correlation coefficient (CC) between the average sunspot numbers (SSNs) and count number of events with a strong correlation of CC = 0.73. We found that most of the storms are associated with the coronal mass ejections (CMEs) and solar flares. These storms are rarely associated with other events. We obtain the average CME speed contributed with geomagnetic storms of $\sim$ 876 km/s, and find a medium correlation coefficient (R = 0.61) typically from the CME speed and the disturbance storm time (Dst) index. We noticed that events out of 54 (63$\%$) are full halo CMEs and 32 (37$\%$) are narrower and/or partial halo CMEs. We found that there exist seven largest storms with magnetic H component $>$ 400 nT associated with severe and extreme storms during solar cycle 23. We present statistical analysis of 104 geomagnetic storms, where the multi-sources data are the solar wind speed, Dst-index, Ap-index, Kp-index, auroral electrojet (AE) index and north–south component of interplanetary magnetic field (IMF-Bz). We studied these storms based on their associations with CMEs, solar flares and CIRs in this period.