Data-constrained Numerical Modeling of the Distribution and Kinetics of Hydrogen (H) Atoms in the Terrestrial Atmosphere

陆地大气中氢 (H) 原子分布和动力学的数据约束数值模拟

基本信息

批准号：
1733946
负责人：
Lara Waldrop
金额：
$ 59.66万
依托单位：
University of Illinois at Urbana-Champaign
依托单位国家：
美国
项目类别：
Continuing Grant
财政年份：
2018
资助国家：
美国
起止时间：
2018-04-01 至 2024-03-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=1733946&HistoricalAwards=false
关键词：
Data constrained Numerical Modeling Distribution

项目摘要

Atomic hydrogen (H) dominates the composition of Earth's atmosphere above 500 km (aka the exosphere, or geocorona). Knowledge of H is important for mesospheric and lower thermospheric heating, and for plasmaspheric and magnetospheric charging following geomagnetic storms. As the lightest neutral species in the atmosphere, H requires the lowest energy to overcome the Earth's gravitational force and escape into interplanetary space. Permanent loss of H has a significant impact on long-term atmospheric evolution.Numerical models of exospheric H assume a population of collisional atoms. However, this assumption has long been known to be oversimplified. Recent measurements made by the PIs of non-thermal, high-energy H atoms in the upper thermosphere bear this out. The goals of this proposal are to refine the PI's radiative transfer models to reflect non-collisional H physics, and to identify the mechanisms that control the distribution and dynamical transport of H atoms in the terrestrial thermosphere and exosphere. The efforts will lead to further understanding of the structure, chemical coupling and energetics of the space-atmosphere interaction region. The work also sheds light on the evolution of the exosphere due to H escape. The new modeling capabilities and inversion techniques can be easily generalized for the study of other planetary atmospheres, particularly that of Mars. The PI is early career scientists, and will train a graduate student in inverse theory, data analysis, and radiative transfer.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.

原子氢（H）在500 km以上（又称Exosphere或Geocorona）的地球大气组成主导。 H的知识对于中层和较低的热层加热以及在地磁风暴后的等离子和磁层充电很重要。作为大气中最轻的中性物种，H需要最低的能量来克服地球的重力并逃脱到星际间空间中。 H的永久损失对长期大气进化具有重大影响。外层H的数量模型假设碰撞原子群体。但是，长期以来，已知这种假设过于简化。在上部热层中非热，高能H原子的PI进行的最新测量结果。该提案的目标是完善PI的辐射转移模型以反映非碰撞H物理学，并确定控制H原子在陆地热层和外层中H原子的分布和动力运输的机制。这些努力将进一步了解空间 - 大气相互作用区域的结构，化学耦合和能量。这项工作还阐明了由于H逃脱而引起的外层的演变。可以轻松地将新的建模功能和反转技术概括为研究其他行星氛围，尤其是火星。 PI是早期的职业科学家，将在逆理论，数据分析和辐射转移方面培训一名研究生。该奖项反映了NSF的法定任务，并使用基金会的知识分子优点和更广泛的影响评估标准，被认为值得通过评估来获得支持。