CEDAR: Terrestrial Airglow Studies Using Astronomical Sky Spectra

CEDAR：使用天文天空光谱进行地面气辉研究

• 批准号: 0437361
• 负责人: Tom Slanger
• 金额: $ 26.09万
• 依托单位: SRI International
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-01-01 至 2007-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0437361&HistoricalAwards=false
• 关键词: CEDAR; Terrestrial; Airglow; Studies; Using

Spectra of the night sky gathered as a by-product of astronomical observations made at two Keck telescopes at Mauna Kea, Hawaii are used to improve our understanding of chemistry and composition in the upper mesosphere and thermosphere. The data acquisition has recently expanded to include similar spectrographic data from the European Southern Observatory in Chile, and from the 9-meter telescope at McDonald Observatory in Texas. The use of the data for aeronomy focuses on three discoveries made in a preceding research effort. First, a ratio of the sodium D1 to D2 emission intensity is found to have a surprising semiannual oscillation, which preliminary investigation indicates is modulated by the O:O2 number density ratio in the upper mesosphere. This research attempts to prove that hypothesis, and thereby establish an unprecedented proxy for determining the density of the dominant species in the upper atmosphere - a long standing and elusive target for ground-based aeronomy. The second research task investigates the ratio of the O(1D):N(2D) ratio (the latter a unique measurement capability of these large telescopes) relative to model values that currently do not reproduce the data. The third research task uses the heretofore unappreciated detail of the OI Rydberg series to peg ratios that can be used for instrument sensitivity calibration throughout the airglow observation community - and thereby improve density determinations made from airglow data.

位于夏威夷莫纳克亚山的两台凯克望远镜所收集的夜空光谱是天文观测的副产品，用于提高我们对上层中间层和热层的化学和成分的理解。数据采集最近扩大到包括来自智利欧洲南方天文台和德克萨斯州麦克唐纳天文台9米望远镜的类似光谱数据。这些数据在航空学中的应用主要集中在之前的研究工作中取得的三个发现。首先，发现钠D1与D2的发射强度之比具有令人惊讶的半年振荡，初步研究表明，这是由中层上层的O:O2数密度比调制的。这项研究试图证明这一假设，从而建立一个前所未有的代理来确定上层大气中优势物种的密度-一个长期存在且难以捉摸的地面航空目标。第二个研究任务是调查O(1D):N（2D）比率（后者是这些大型望远镜独特的测量能力）相对于目前无法重现数据的模型值的比率。第三项研究任务是利用OI Rydberg系列迄今为止未被重视的细节来固定比率，这些比率可用于整个气辉观测社区的仪器灵敏度校准，从而改进气辉数据的密度测定。