[P-EM13] 太陽地球系結合過程の研究基盤形成

[PEM13-P10] Spectroscopic and imaging observations for short-wavelength infrared aurora and airglow at Longyearbyen (78.2°N, 15.6°E) coordinated with EISCAT Svalbard radar and VLF/LF radio wave receivers.

*西山 尚典^1,2、鍵谷 将人³、小川 泰信^1,2,4、土屋 史紀³、細川 敬祐⁵、坂野井 健³ (1.国立極地研究所、2.総合研究大学院大学、3.東北大学大学院 理学研究科附属 惑星プラズマ・大気研究センター、4.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、5.電気通信大学)

キーワード：オーロラ・大気光、短波長赤外、EISCAT Svalbard radar、長波帯標準電波受信、磁気圏-電離圏結合、中間圏-下部熱圏

We are currently developing and testing a 2-D imaging spectrograph to evaluate spatial and temporal characteristics of dayside aurora. It is designed for short-wavelength infrared (SWIR) wavelength ranging from 1.1 to 1.3 microns covering strong auroral emissions in N₂⁺ Meinel band (0-0) and N₂ 1st Positive bands (1-2 and 0-1) as well as airglow emissions in OH Meinel bands (5-2, 6-3, and 7-4) and O₂ IR band. Its field-of-view (FOV) and angular resolution are 55 degrees and 0.11 degrees per pixel, respectively. If a 30-microns slit is used, wavelength resolutions are 2230 and 5070, with two different gratings (950 lpmm and 1500 lpmm). A signal-to-noise ratio for 1 kR emissions is expected to be larger than 1.0 in a few seconds exposure time. Therefore, we can investigate temporal variability of dayside reconnection and pulsating auroras with sufficient sampling rates of a few seconds. In a test observation, we successfully measured airglow spectrum for OH (7-4) band and O₂ IR band in a twilight condition (solar zenith angle, SZA, is about 96°).
The spectrograph will be installed at The Kjell Henriksen Observatory/The University Centre in Svalbard (KHO/UNIS), Longyearbyen (78.2°N, 15.6°E) by the end of 2021. Taking advantage of its location, 24-hours continuous observations can be expected (SZA larger than 96°) near the winter solstice. Coordinated studies with active/passive radio remote sensing, such as EISCAT Svalbard radar and VLF/LF radio wave receivers, are planned. In addition, we start to consider a brand-new SWIR imager or echelle spectrograph that will be introduced at KHO/UNIS after 2022. A detailed specification of the instrument is presented as well.