[P-EM13] Coupling Processes in the Atmosphere-Ionosphere System

[PEM13-P11] A pilot study for tomographic reconstruction of ionospheric O+ distribution from ISS-IMAP/EUVI data

*中野 慎也^1,2、穂積 裕太³、齊藤 昭則⁴、吉川 一朗⁵、山崎 敦⁶、吉岡 和夫⁵、村上 豪⁶ (1.情報・システム研究機構　統計数理研究所、2.情報・システム研究機構　データサイエンス共同利用基盤施設 データ同化研究支援センター、3.情報通信研究機構、4.京都大学大学院理学研究科、5.東京大学大学院新領域創成科学研究科、6.宇宙航空研究開発機構 宇宙科学研究所)

キーワード：電離圏、酸素イオン密度分布、極端紫外光観測

An extreme ultraviolet (EUV) imager, EUVI-B, on board the International Space Station (ISS) under the International Space Station-Ionosphere-Mesosphere-Atmosphere Plasmasphere cameras (ISS-IMAP) mission was originally intended to observe EUV emissions at 83.4 nm scattered by O+ ions. However, our previous study (Nakano et al., 2021) has reported that EUVI-B mostly observed 91.1 nm emission due to recombination between O+ ions and electrons. This result suggests that the observed signal is approximately proportional to the line-of-sight integral of the square of O+ density and that the EUVI-B data can be used for tomographic reconstruction of O+ distribution in the ionosphere.

In this study, we conduct a pilot study for reconstruction oxygen ion distribution from the EUVI-B data. We use multiple images to estimate the three-dimensional O+ distribution in the vicinity of the ISS orbit of the low-latitude ionosphere. We will report the current status and future prospect of our study based on the ISS-IMAP/EUVI-B data.

Reference
S. Nakano, Y. Hozumi, A. Saito, I. Yoshikawa, A. Yamazaki, K. Yoshioka, and G. Murakami, EUV signals associated with O⁺ ions observed from ISS-IMAP/EUVI in the nightside ionosphere, Earth Planets Space, v. 73, 151, doi:10.1186/s40623-021-01479-0, 2021.