[P-EM09] Space Weather and Space Climate

[PEM09-11] Integrated multi-point measurements of the solar erupted magnetic flux rope during the CME passage on October 2021 from the solar surface through the inner heliosphere

*Yumi Bamba^1,2, Takuya Hara³, Katsuhide Marubashi¹, Kazumasa Iwai², Tomoaki Hori², Go Murakami⁴, Beatriz Sanchez-Cano ⁵ (1.National Institute of Information and Communications Technology, 2.Nagoya University, 3.University of California, Berkeley, 4.Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 5.School of Physics and Astronomy, University of Leicester, UK)

Keywords:Coronal Mass Ejection, Interplanetary Magnetic Flux Rope, Solar Flare

Coronal Mass Ejection (CME) has agreat impact on our social infrastructures, such as, global positioning system satellites and electric power supply systems. It is thus important from the perspective of space weather forecast to predict CME occurrence, propagation, and its arrival to Earth. In particular, one of the most important issues on space weather forecast is to predict the geometrical structure of a magnetic flux rope (MFR) embedded in a CME, and its passage duration. In this study, we investigated an M1.6 flare and the associated CME that occurred on October 9, 2021, in order to understand how the MFR geometry, especially the axial field orientation, changes as the CME propagated through the inner heliosphere. We first analized the formation and eruption processes and the axial field orientation of the MFR on the solar surface using solar data obtained by the Solar Dynamics Observatory (SDO). We next applied a model fitting technique to in-situ measurment data in the interplanetary space, assuming that a MFR is a cylindrical shape with the constant-α force-free, and self-similar expansion. The interplanetary data were obtained by BepiColombo at 0.33 AU, Solar Orbiter at 0.68 AU, STEREO-A at 0.96 AU, and ACE. The model fitting allows us to estimate the MFR geometry, such as its axial field orientation, cylinder radius, and chirality, at each spacecraft location in the inner heliosphere. Combining the results from solar and in-situ data, we discuss how the MFR was erupted from the Sun and further evolved as it propagated through the inner heliosphere.