[P-CG38_1PO1] 惑星大気圏・電磁圏

[PCG38-P06] ハワイ・マウナケア山頂における赤外ヘテロダイン分光惑星観測計画

*中川 広務¹、青木 翔平¹、笠羽 康正¹、村田 功¹、佐川 英夫² (1.東北大学、2.情報通信研究機構)

キーワード：赤外分光, ヘテロダイン, レーザー, 観測, 惑星大気, 同位体

We propose a new developed infrared heterodyne instrument, called Mid-Infrared LAser Heterodyne Instrument (MILAHI), for our dedicated telescope at the top of Mt. Haleakala, Hawaii. It addresses the key physical/meteorological parameters, such as the atmospheric temperature profiles, abundance profiles of the atmospheric compositions and their isotopes, and wind velocity. The observational sensitivity of MILAHI is discussed in this paper. The scientific target of MILAHI is to understand highly variable phenomena in the planetary atmospheres. The nature of atmospheric activity in various time-scale will be investigated by continuous monitoring with our dedicated telescope, in order to increase our understanding of planetary atmospheric dynamics, photochemistry, and meteorology. New measurements with high spatial/spectral resolutions constrain the three-dimensional distributions of temperature and compositions. The D/H and other isotopic ratios, diagnostic of the terrestrial atmosphere evolution, will be accurately measured in H₂O and CO₂. The atmospheric chemistry will be studied by monitoring O₃, H₂O₂, H₂O, and HDO. Mapping of the H₂O isotopes reveal the mechanism of complex interaction between regolith-aerosols-atmosphere-polar caps on Mars. Direct measurements of wind velocity and temperature allow the first monitoring of the middle atmosphere oscillations to investigate the effects of the gravity waves from the lower atmosphere on the upper atmosphere for various seasons and dust loadings. A number of organics molecule bands in the mid-infrared regime will be accurately measured in planetary/cometary/stellar atmospheres. In addition to these interconnected objectives, serendipitous searches with our advantage of dedicated use for astronomical/atmospheric transient events which occur at frequent and unpredictable intervals (e.g. dust storm) will enhance our knowledge of the composition and dynamics of the astronomical sources.