Geomagnetic Consequences of Interacting CMEs of June 13-14, 2012
Abstract
We have studied the consequences of interacting coronal mass ejections (CMEs) of June 13-14, 2012 which were directed towards Earth and caused a moderate geomagnetic storm with Dst index ~ -86 nT. We analysed the in-situ observations of the solar wind plasma and magnetic field parameters obtained from the OMNI database for these CMEs. The in-situ observations show that the interacting CMEs arrive at Earth with the strongest (~ 150 nT) Sudden Storm Commencement (SSC) of the solar cycle 24. We compared these interacting CMEs to a similar interaction event which occurred during November 9-10, 2012. This occurred in the same phase of the solar cycle 24 but resulted in an intense geomagnetic storm (Dst ~ -108 nT), as reported by Mishra et al. (2015). Our analysis shows that in the June event, the interaction led to a merged structure at 1 AU while in the case of November 2012 event, the interacted CMEs arrived as two distinct structures at 1 AU. The geomagnetic signatures of the two cases reveal that both resulted in a single step geomagnetic storm.
- Publication:
-
Space Weather of the Heliosphere: Processes and Forecasts
- Pub Date:
- August 2018
- DOI:
- 10.1017/S1743921317010857
- Bibcode:
- 2018IAUS..335...65S
- Keywords:
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- Coronal mass ejections;
- solar wind plasma;
- magnetic field;
- geomagnetic storm.