A comparative study on electron contribution to the ring current during CME and CIR driven geomagnetic storms using RAM-SCB simulations and Arase and ground magnetic data

Abstract

<p>Geomagnetic storms are the main component of space weather and are driven by coronal mass ejections (CMEs) or corotating interaction regions (CIRs). During the main phase of geomagnetic storms, the ring current enhances and a global decrease in the <em>H</em> component of the geomagnetic field is observed. The storm time distribution of ring current ions and electrons in the inner magnetosphere depend strongly on their transport in evolutions of electric and magnetic fields along with acceleration and loss. Recently, we showed that the electron pressure contributes to the depression of ground magnetic field during the storm time by comparing <strong>R</strong>ing current <strong>A</strong>tmosphere interactions <strong>M</strong>odel with <strong>S</strong>elf <strong>C</strong>onsistent magnetic field (RAM-SCB) simulation, Arase in-situ plasma/particle data, and ground-based magnetometer data [<em>Kumar et al.,</em> 2021]. In this study, we compare the contribution of electron pressure to the ring current during selected CIR and CME geomagnetic storms using ground observations and the self-consistent inner magnetosphere model: RAM-SCB. The previous results show that the ions are the major contributor (~ 90 %) to the total ring current and the electron contributes ~10 % to the ring current pressure in the post-midnight to dawn sector where electrons flux is higher compared to ions flux. As CIR and CME storms have different origins, we will discuss expected differences in the contribution of electron pressure to the ring current.</p>