[P-EM16] Heliosphere and Interplanetary Space

[PEM16-P03] Propagation of CME reconstructed by the MHD simulation based on IPS and BepiColombo observations

*Kazumasa Iwai¹, Beatriz Sanchez-Cano², Daikou Shiota³, Go Murakami⁴, Munetoshi Tokumaru¹, Ken'ichi Fujiki¹, Yoshizumi Miyoshi¹ (1.Institute for Space–Earth Environmental Research (ISEE), Nagoya University, 2.University of Leicester, 3.NICT, 4.ISAS/JAXA)

Keywords:CME, Interplanetary space scintillation (IPS) , MHD simulation, BepiColombo

Interplanetary space scintillation (IPS) observation that uses radio scattering phenomena is an important technique to detect the coronal mass ejections (CMEs) propagating in the interplanetary space. In addition, more spacecraft are operated in the inner heliosphere in recent years. It is expected that CME propagation can be reproduced more accurately by integrating these spacecraft observations with IPS observations. In this study, we investigated a CME generated around the center of the solar disc in early October 2021, when the BepiColombo satellite and the Earth were radially aligned. We simulated CME propagation using a global MHD simulation, SUSANOO-CME, in which CMEs were modeled as spheromaks, and the IPS data were synthesised from the simulation results. We found that the simulation that best fits the IPS observation well reconstructs the CME arrival at BepiColombo. This is probably because BepiColombo was close to the region of the inner heliosphere where IPS observations are sensitive to the CME. On the other hand, the simulated CME that best fits the IPS and BepiColombo observations arrived at the Earth about five hours earlier than it actually was. This result suggests that the simulation could not reproduce the propagation of CME between the BepiColombo satellite, which was located at about 0.3 AU, and the Earth. This discrepancy could be explained by the density of background solar wind, that is reproduced by the empirical models in our simulation, has lower than that of observed at 1AU during the period of interest. The lower density of the solar wind can cause the smaller deceleration of the CME that can lead its faster propagation.