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

[PEM13-29] Bright bands of the mesospheric airglow observed from the international space station

*齊藤 昭則¹、坂野井 健²、穂積 裕太³ (1.京都大学大学院理学研究科地球物理学教室、2.東北大学大学院理学研究科惑星プラズマ・大気研究センター、3.情報通信研究機構)

キーワード：大気光、中間圏、熱圏、国際宇宙ステーション、ISS-IMAP

Bright band-like structures of the mesospheric airglow have been observed from space in the equatorial region. Their horizontal scale size is several hundreds of kilometers. Because it is larger than the field-of-view of the ground-based all-sky imagers, these bright bands are difficult to be identified from the ground-based observations. Although it has been captured by limb observations from satellites, the horizontal structures and the occurrence characteristics has not been studied in detail. Nadir-viewing observation of the mesospheric airglow from the international space station enabled to capture the structures of these band-like structures for the first time. The observation was carried out by Visible and near Infrared Spectral Imager (VISI) instrument of the International Space Station-Ionosphere, Mesosphere, upper Atmosphere and Plasmasphere mapping (ISS-IMAP) mission from the Exposed Facility of Japanese Experiment Module between August 2012 and August 2015. The airglow emission in 762nm wavelength from the molecular oxygen around 95km altitude was observed with 10km of the horizontal resolution. The FOV width of VISI's 762nm observations was 600 km in the direction perpendicular to the ISS trajectory, and longer than 10,000km along the trajectory. They are idealistic to capture these mesospheric structures. The bright band is interpreted to be caused by the atmospheric tide in the mesosphere. In the presentation, the morphological and occurrence features of the structures will be reported, and the physical mechanism of the generation will be discussed.