A Theoretical Framework for Photoionization and Photodetachment Rate Calculations in the Lower Ionosphere

该奖项将支持为陨石烧蚀事件产生的金属物种的光致电离和光剥离速率建立一个模型框架。其来源是可能由瞬变发光事件(精灵、精灵、闪电)、极光活动和流星轨迹产生的O2和N2分子带发射的多个EUV、UV和可见光系统。这些结果将使对D区和较低热层零星层可能对电离层组成或具有几公里范围的空间尺度的电离层动力学的局部性影响的具体计算成为可能。这项工作将支持研究生和暑期本科生。这项工作主要是基于这样一个事实，即金属物种的光致电离阈值相对于其他大气成分如氮气或氧气的电离阈值相当低。因此，TLE、极光和流星轨迹的照明源将具有足够的能量，以实现中性金属物种的电离或电子从受流星或沉淀电子或TLE活动影响的区域内的任何电离层负离子中分离。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

This award will support the development of a modeling framework for photoionization and photo-detachment rates of metallic species generated by meteoric ablation events. The sources are multiple EUV, UV, and visible systems of O2 and N2 molecular band emissions that might be generated by transient luminous events (sprites, elves, lightning), auroral activity, and meteor trails. These results would make possible specific calculations for the D-region and lower thermosphere sporadic layers of possible localized effects upon ionospheric composition or ionospheric dynamics featuring spatial scales a few kms in extent. A graduate student and summer undergraduate students would be supported in this work.This work is based primarily upon the fact that the photo-ionization thresholds of metallic species is quite low relative to the ionization thresholds of other atmospheric constituents such as N2 or O2. Thus, the illumination sources of TLE, aurora, and meteor trails would be sufficiently energetic to achieve the ionization of neutral metallic species or the detachment of electrons from any ionospheric negative ions present within the region affected by meteors or precipitating electrons or TLE activity.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.