Development of Technology to Automatically Determine Parameters for More Accurate Solar Energetic Particle Simulations through Mathematical Optimization

2026-10-23

An international research group including Professor Kazumasa Iwai (Division for Heliospheric Research) and Designated Professor Kanya Kusano (Office for the Development of Interdisciplinary Research Strategy) of the Institute for Space–Earth Environmental Research (ISEE), Nagoya University, together with Fujitsu Limited (Fujitsu), the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), the National Institute of Information and Communications Technology (NICT), and other research partners, has developed the world’s first technology that uses observational data from five spacecraft to objectively, reproducibly, and automatically determine parameters for physical simulations of solar energetic particle (SEP) acceleration and transport. SEPs can expose astronauts to radiation and cause satellite malfunctions.

This study utilized SUSANOO, a magnetohydrodynamic (MHD) simulation model developed at ISEE. In addition, interplanetary scintillation (IPS) observations from ISEE were used to compare and select coronal mass ejection (CME) propagation simulations for use in the SEP acceleration and transport calculations.

The results were published in the journal Scientific Reports. Applying this technology to future SEP arrival prediction is expected to help reduce satellite failures and radiation exposure risks for astronauts, and contribute to improving the safety of sustainable human activities on the Moon.

Publication Information:
Authors: Hiroyuki Tako Ishikawa, Naho Fujita, Yuta Kato, Miki Kurihara, Takashi Minoshima, Daikou Shiota, Kazumasa Iwai, Marco Pinto, António Pessanha Gomes, Go Murakami, Kanya Kusano & Chihiro Mitsuda

Title: Automated Optimization of Solar Energetic Particle Acceleration and Transport Parameters Against Five-Spacecraft Observations of the 9 October 2021 Event
Journal: Scientific Reports (2026)
Publication Date: October 20, 2026
DOI: 10.1038/s41598-026-70869-9
URL: https://doi.org/10.1038/s41598-026-70869-9

Press Release by Nagoya University
https://www.nagoya-u.ac.jp/researchinfo/result/2026/10/jamstecnict.html