CEDAR: Remote Oxygen Sensing by Ionospheric Excitation (ROSIE)

这个项目的主要目的是分析和模拟电离层修正(IM)实验中630态氧红线的观测结果，并提取相应的局域O原子密度。与过去在解释此类观测时忽略氧原子的常见做法不同，最近关于O(3P)对O(1D)驰豫的实验研究揭示了氧原子在与IM实验相关的高度控制O(1D)寿命的主导作用。使用最新的O(1D)被O、N_2和O_2碰撞弛豫的速率系数，现在可以可靠地分析IM实验中观察到的红线衰变，从而探测电离层中的局域O原子密度。该项目将利用一种创新的方法在与IM实验相关的高度远程探测O原子，测试目前电离层中O原子密度的模型，并研究其在加热设施附近的时间、季节、高度和空间变化。将从IM站点获取相关数据集，重点是HAARP和EISCAT的数据，以便确定衰变所隐含的O原子密度，并与标准大气组成模型如MSIS和Jacchia进行比较。这些结果可能会对计划新的IM实验有用，最终目标是在特定地点生成电离层O原子地图，以便与模型进行比较。对电离层中氧原子密度的遥感和对其波动的监测一直是一个特别具有挑战性的问题。该项目的更广泛影响包括挪威特罗姆索大学、英国兰开斯特大学、空军研究实验室和SRI国际之间的国际合作努力，以及对SRI暑期本科生的培训和研究经验的贡献。

The main objective of this project is to analyze and model observations of the 630-nmatomic oxygen red line emission from ionospheric modification (IM) experiments and to extract the corresponding local O-atom densities. In contrast to the common practice of ignoring oxygen atoms in interpreting such observations in the past, recent experimental studies on the relaxation of O(1D) by O(3P) have revealed the dominant role oxygen atoms play in controlling the lifetime of O(1D) at altitudes relevant to IM experiments. Using the most up-to-date rate coefficients for collisional relaxation of O(1D) by O, N2, and O2, it is now possible to analyze reliably the red line decays observed in IM experiments and thus probe the local O-atom density in the ionosphere. This project will take advantage of an innovative approach to remotely probe O-atoms at the altitudes relevant to IM experiments, to test the current models for O-atom density in the ionosphere, and to study its temporal, seasonal, altitude and spatial variation in the vicinity of heating facilities. Relevant data sets will be acquired from IM sites, with emphasis on data from HAARP and EISCAT, in order to determine the O-atom densities implied from the decays and to make comparisons with standard atmospheric composition models such as MSIS and Jacchia. The results will likely be of use in planning new IM experiments, and the ultimate goal is to generate ionospheric O-atom maps over a particular site, to be compared to models. Remote sensing of O-atom densities and monitoring of their fluctuations in the ionosphere has been a particularly challenging problem. The broader impacts of the project include international collaborative efforts between Tromso University, Norway, Lancaster University, U.K., the Air Force Research Laboratory, and SRI International, and the contribution to the training and research experiences of summer undergraduate students at SRI.