5:15 PM - 7:15 PM
[PEM10-P08] Interaction among multiple CMEs to result in May 2024 Superstorm
Keywords:Coronal mass ejection , solar wind , IMF
The space storm that occurred in May 2024 became a phenomenon of a scale rarely seen in history, with aurora visible in extremely wide areas of the world, including Japan. One of the reasons for this event is that the solar wind that arrived at the Earth on May 10-12 was in a state far from normal, with a maximum density of more than 50 particles/cc and a maximum southward magnetic field of more than 40 nT. This solar wind structure is considered to be generated by multiple CMEs associated with solar flares, including the X-class flares occurred continuously in a short period of time of May 8-10. It is thought that the high-speed CMEs interacted with each other and arrived at the Earth as a single complex body, but the details are difficult to clarify.
In this study, we analyzed solar flares and CMEs that propagated toward the Earth during this period, which were observed by the SDO satellite and SOHO/LASCO, and calculated the propagation of the CMEs in the solar wind with MHD simulation (SUSANOO-CME), and examined the correspondence between the solar wind structure observed in situ and the solar flares and CMEs. Interplanetary scintillation (IPS) observations of the Institute for Space-Earth Environmental Research, Nagoya University are also used the examination of the MHD simulation. In the multiple CMEs that occurred on May 8-9, the propagation speed of the succeeding CMEs was higher than that of the preceding CMEs, and it was seen that they caught up and interacted with each other during propagation in interplanetary space. As a result, it showed that compression occurred in the shock waves of the succeeding CMEs and a prevention of the expansion of the middle CMEs caught between other CMEs, leading to the formation of a high-speed, high-density, and high-magnetic field structure. However, since it is difficult to identify the correspondence between phenomena observed in the solar corona and in situ measurement, we report the results of comparison and consideration of simulation results in which data of different CMEs were input.
In this study, we analyzed solar flares and CMEs that propagated toward the Earth during this period, which were observed by the SDO satellite and SOHO/LASCO, and calculated the propagation of the CMEs in the solar wind with MHD simulation (SUSANOO-CME), and examined the correspondence between the solar wind structure observed in situ and the solar flares and CMEs. Interplanetary scintillation (IPS) observations of the Institute for Space-Earth Environmental Research, Nagoya University are also used the examination of the MHD simulation. In the multiple CMEs that occurred on May 8-9, the propagation speed of the succeeding CMEs was higher than that of the preceding CMEs, and it was seen that they caught up and interacted with each other during propagation in interplanetary space. As a result, it showed that compression occurred in the shock waves of the succeeding CMEs and a prevention of the expansion of the middle CMEs caught between other CMEs, leading to the formation of a high-speed, high-density, and high-magnetic field structure. However, since it is difficult to identify the correspondence between phenomena observed in the solar corona and in situ measurement, we report the results of comparison and consideration of simulation results in which data of different CMEs were input.