Resolving Long-Standing E-region Data/Model Discrepancies

解决长期存在的电子区域数据/模型差异

• 批准号: 1849014
• 负责人: Joseph Evans
• 金额: $ 45.53万
• 依托单位: Computational Physics Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-08-01 至 2024-09-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1849014&HistoricalAwards=false
• 关键词: Resolving; Long; Standing; region; Data

This award addresses a long-standing problem of systematic discrepancies between modeled and observed plasma densities in the ionized portion of the upper atmospheric layer near 110 km in altitude (ionospheric E region). It is hypothesized that a key reason for these discrepancies is low-resolution model parameters related to ionization reactions of O, O2, and N2 with solar photons (photoionization). Insufficient resolution employed by the current models means that narrow "windows" of photoionization are not being properly accounted for. This work will improve the understanding of these windows of ionization for the three most important species in the E region (O, O2, and N2) and the effects on E-region ionization rates and densities. New parameters describing ionization reactions (ionization cross sections) will be calculated for all three species using modern quantum-mechanical methods. These parameters are important since they determine the probability that an ionization process will occur. The new cross sections will be provided to the atomic and molecular physics community. This will be also important to astrophysics and planetary sciences, which will improve synergies between different fields. In addition, the project will expand student opportunities to engage in research by offering research projects to students at one of the partner institutions with a diverse student population. The work supported by this award will (1) calculate new cross sections for all three major species using modern quantum-mechanical methods for both photo- and photoelectron-impact ionization, (2) develop further the atmospheric photoionization code and the Atmospheric Ultraviolet Radiance Integrated Code (AURIC) to properly incorporate the improved ionization rates, photoelectron fluxes, and electron densities, (3) validate the new model outputs by comparing with E-region photoelectron fluxes measured by the low-Earth-orbit satellites and E-region electron densities measured by the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) satellites and the Arecibo incoherent scatter radar, and (4) provide the developed models to the community.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.

该奖项解决了海拔 110 公里附近的上层大气层电离部分（电离层 E 区域）中模拟和观测的等离子体密度之间长期存在的系统差异问题。据推测，造成这些差异的一个关键原因是与 O、O2 和 N2 与太阳光子的电离反应（光电离）相关的低分辨率模型参数。当前模型采用的分辨率不足意味着光电离的狭窄“窗口”没有得到适当的考虑。这项工作将增进对 E 区三种最重要物质（O、O2 和 N2）的电离窗口及其对 E 区电离率和密度的影响的理解。将使用现代量子力学方法计算所有三种物质的描述电离反应（电离截面）的新参数。这些参数很重要，因为它们决定了电离过程发生的概率。新的横截面将提供给原子和分子物理学界。这对于天体物理学和行星科学也很重要，这将改善不同领域之间的协同作用。此外，该项目还将通过向拥有多元化学生群体的合作机构之一的学生提供研究项目，扩大学生参与研究的机会。该奖项支持的工作将（1）使用现代量子力学方法计算所有三个主要物种的新横截面，用于光和光电子碰撞电离，（2）进一步开发大气光电离代码和大气紫外线辐射集成代码（AURIC）正确结合改进的电离率、光电子通量和电子密度，（3）通过与由由气象、电离层和气候星座观测系统 (COSMIC) 卫星和阿雷西博非相干散射雷达测量的低地球轨道卫星和 E 区电子密度，以及 (4) 向社区提供开发的模型。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。