Incoherent Scatter Radar Study of the F1 Region Composition, Coupling, Dynamics and Energetics

电离层是大气层的导电层，从100公里延伸到太空边缘。本研究针对的是电离层F1层，跨度为130-230公里。这个区域由低能级的分子离子和上界的原子离子组成。这种成分的混合导致对F1区域的研究比电离层的其他部分要少，因为电离层的成分更简单。然而，F1电场和离子漂移在空间和时间上是高度可变的，因此了解这个区域对于电磁波传播、空间天气预报及其对通信和定位行业的影响显然是重要的。非相干散射雷达（ISR）是研究F1层的主要手段。雷达信号（“回波”）可以产生有关风和温度的信息，但这一过程缺乏独特性，因为离子质量和电子/离子温度的不同组合可以产生相同的回波功率。首席研究员（PI）将结合ISR在阿雷西博观测到的离子和等离子体发射来推断温度、成分和速度，而不需要传统的假设，这些假设限制了之前的努力。他将研究海拔、季节和太阳活动的依赖性，以及维持F1的光化学和动力过程之间的平衡。这项工作有助于我们对电离层物理的基本理解，同时展示了挖掘ISR测量的新策略。随着阿雷西博天文台从美国国家科学基金会（NSF）的管理移交给中佛罗里达大学（University of Central Florida）的新管理，PI的努力肯定了它在科学卓越方面的声誉。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The ionosphere is the electrically conductive layer of the atmosphere that extends from 100 km to the edge of space. This research addresses the F1 layer of the ionosphere that spans 130-230 km. This region is populated by molecular ions at the lower levels and atomic ions at the upper boundary. This mixture of constituents has led to the F1 region being less studied than other parts of the ionosphere where the composition is simpler. However, F1 electric fields and ion drifts are highly variable in space and time, so understanding this region is clearly important for electromagnetic wave propagation, space weather prediction, and their ramifications for communications and positioning industries. Incoherent scatter radars (ISR) are the primary instruments to study the F1 layer. Radar signals ("echoes") can yield information about wind and temperature, but the process suffers from a lack of uniqueness, as different combinations of ion mass and electron/ion temperatures can present with the same echo power. The Principal Investigator (PI) will combine ion and plasma emissions observed by the ISR at Arecibo to infer temperature, composition and velocity without the traditional assumptions that have constrained previous efforts. He will examine altitude, seasonal and solar activity dependences, and the balance between photochemical and dynamical processes that maintain F1. This work contributes to our fundamental understanding of ionospheric physics, while showcasing new strategies for mining ISR measurements. The PI's efforts affirm Arecibo Observatory's reputation for scientific excellence as the facility transitions from National Science Foundation (NSF) management to its new administration by the University of Central Florida.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.