[P-EM16] Heliosphere and Interplanetary Space

[PEM16-08] Comparison of Multi-Spacecraft Observations and Numerical Modeling of the October 2021 SEP Event and Discussion Towards Prediction

*Yuta Kato^1,2, Miki Kurihara^4,5, Kanya Kusano², Takashi Minoshima³, Daikou Shiota^6,2, Kazumasa Iwai², Chihiro Mitsuda^1,2 (1.Fujitsu Limited, 2.Institute for Space–Earth Environmental Research, Nagoya University, 3.Center for Mathematical Science and Advanced Technology, Japan Agency for Marine-Earth Science and Technology , 4.Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 5.Graduate School of Science, Department of Astronomy, The University of Tokyo, 6.Space Environment Laboratory, Radio Propagation Research Center, Radio Reseach Insittute, National Institute of Information and Communications Technology)

Keywords:Solar Energetic Particles, Numerical Simulation, Machine Learning

Fujitsu Limited and the Institute for Space-Earth Environmental Research (ISEE), Nagoya University, have been conducting joint research since September 2023 to ensure the safety of deep-space exploration. This initiative has involved using AI techniques to predict solar energetic particle (SEP) events (cf. JpGU 2024, P-EM11, Kato et al.).

This presentation discusses the acceleration and transport mechanisms of SEP events using numerical modeling, and their application to prediction, leveraging AI and other technologies. Specifically, we present initial results comparing numerical simulations with SEP observations from multiple spacecraft (PSP, SolO, BepiColombo, SOHO, and STEREO-A) during the October 2021 SEP event, where these spacecraft were positioned around the magnetic field lines connecting the Sun to Earth (cf. Palmerio et al. 2024).

We reconstructed the CME propagation using the SUSANOO model (Shiota et al.2014, 2016) based on interplanetary scintillation observation data (Iwai et al. 2019), and derived CME shock parameters. Then we obtained the energy spectrum of SEPs using a method based on the Focused Transport equation (cf. 2024 JpGU P-EM16 Minoshima et al.) based on the derived CME shock parameters. This model utilizes three parameters: the mean free path of SEP particles, acceleration rate at the CME shock, and injection efficiency. Since our goal is to predict SEP event particle fluxes variation using this method, we will also report on our progress in developing methods to predict the optimal ranges of these parameters.