- 學位論文
金星尾波區熱氧圈的形成初探
Formation of an Extended Halo of Hot Oxygen Atoms in the Wake Region of Venus
摘要
先鋒－金星1號（Pioneer Venus Orbiter）的探測結果證實了金星熱氧圈（hot oxygen corona）的存在。構築熱氧圈的熱氧原子O*是由於金星離子球層的O2+受到電子撞擊，解離後重新再結合而成。無獨有偶，先鋒－金星1號也在金星高層大氣中探測到由晝半球往夜半球大規模流動的離子流，並且此離子流在金星晨昏線（terminator）上方約500公里處將可達到每秒5公里的流速。如此大型的晝夜向對流可能影響熱氧原子的運動軌跡，進而導致熱氧圈的不均勻分布。本研究旨在建立一個二維的蒙地卡羅（Monte-Carlo）模型，並模擬出金星熱氧圈在此離子流的影響下可能的分布情形。
並列摘要
From the detailed measurements in Venusian ionosphere by the Pioneer Venus Orbiter, it was well known that there is a large day-to-night flow of ionospheric plasma with the horizontal speed reaching a value as high as 5 km/s at 500-km altitude near the terminator. This large-scale anti-sunward convective motion could lead to a significant distortion of the hot oxygen corona maintained by oxygen atoms from O2+ dissociation recombination into a tadpole-like structure. A Monte-Carlo model is developed to simulate the two-dimensional configuration of such a hot oxygen corona.