木衛一Io，是木星系統裡最靠近木星的伽利略衛星，它擁有超過 400 座的火山，以及以二氧化硫為主體的稀薄大氣層。在每次環繞木星的公轉，木衛一將會通過木星的陰影形成木衛星蝕，其沒入陰影的時間持續約兩個小時。因此當木衛星蝕發生時，太陽輻射的能量來源將受到限制，木衛一地表溫度預期將會急遽下降，進而導致由熱昇華控制的大氣暫時崩潰，而根據先前的觀測分析，其推論是可能發生的，我們可確定的是木衛星蝕將對木衛一的大氣演變有重要的影響。另一方面，其他的伽利略衛星像是木衛二 Europa 和木衛三 Ganymede，它們具有以磁層離子濺射和水冰的熱昇華產生的外氣層，在通過木星陰影時也會發生類似的瞬變效應。在未來的太空探索中，JUICE 等太空任務預計將詳細研究在木衛星蝕發生時對衛星的大氣結構與形成過程的影響。在本次研究中，我們將呈現在日光下與通過木星陰影區的木衛一的表面溫度分佈，然後討論大氣結構的可能相應物理結果。此外，我們針對木衛一的地表建立一個的地表雙層模型，在二氧化硫霜上覆蓋著非二氧化硫的物質(假設為塵埃層)，來研究二氧化硫在氣壓平衡下對地表特性的可能關聯性。;Io, one of Jupiter′s large moons and its atmospheric composition of the atmosphere is mainly sulfur dioxide. It will enter the shadow of Jupiter for rough two hour each orbits. Because of the sudden shut-off of solar radiation, the temperatures on the sunlit surfaces would drop precipitously leading to the temporary collapse of the atmospheres controlled by thermal sublimation. Such effect has important influence of the time variation of the SO₂ atmosphere of Io according to previous astronomical measurements. By the way, similar transient effects would occur for the other Galilean moons, namely, surface-bound exospheres of Europa and Ganymede were generated by magnetospheric ion sputtering and thermal sublimation of water ice. Such a unique phenomenon diagnostic of the atmospheric structure and formation process will be studied in detail by future space missions like JUICE. In this research, we will present the surface temperature profiles of Io in common and in the vicinity of the shadow zone of Jupiter and then discuss the corresponding physical consequences on their respective atmospheric structure. Besides, we examine the dependence of the SO₂ equilibrium pressure on the surface property of Io by introducing a two layer model with a dust mantle overlying the SO₂ frost.
