Collaborative Research: Exploring Low-Latitude Ionospheric Irregularities in the Upper E-Region Valley Using Observations, Theory, And Simulations

该方案将建模工具与非相干散射雷达测量相结合，研究赤道电离层150公里附近散射的雷达回波源。当在高度时间平面上绘制时，这些回声就像一条“项链”。结构复杂的后向散射首先出现在黎明时分150公里附近，中午下降到130公里左右，下午晚些时候上升到150公里，日落时消失。直到2016年，这些回声的原因在很大程度上仍然未知，当时pi们似乎认为它们是光电子驱动的电子波的表现。这项工作的目标是建立一个连贯的、基于物理的、系统科学的对150公里回声的理解。根据这份新合同，PIs将继续他们的理论和实验研究，将额外的过程纳入他们的模型，并与Jicamarca雷达和电离层探空仪数据进行比较。更广泛的影响包括指导研究生、本科生和高中生。推进对电离层物理的理解，能够解释电离层雷达特征和电离层结构，有利于空间天气建模和预测。2016年的工作得到了大众媒体的广泛关注，从而激发了公众对等离子体物理研究的兴趣。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。

This proposal combines modeling tools with incoherent scatter radar measurements to investigate the sources of radar echoes scattered from the equatorial ionosphere near 150 km. When plotted in the altitude-time plane, these echoes resemble a "necklace". Intricately structured backscatter first appears at dawn near 150 km, descends to ~130 km by midday, lofts to150 km by late afternoon, and disappears at sunset. The cause of these echoes remained largely unknown until 2016, when the PIs plausibly argued they were manifestations of photoelectron-driven electron waves. The goal of this work is to build a cohesive, physics-based, system-science understanding of the 150-km echoes. Under this new award, the PIs will continue their theoretical and experimental investigations by incorporating additional processes into their model, and comparing with Jicamarca radar and ionosonde data. Broader impacts include mentoring of graduate, undergraduate, and high-school students. Advancing understanding of ionospheric physics, and being able to interpret ionospheric radar signatures and ionospheric structuring benefits space weather modeling and prediction. The 2016 work received much attention in the popular press, and thus stimulated public interest in plasma physics research.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.