Collaborative Research: Ionospheric Density Response to American Solar Eclipses Using Coordinated Radio Observations with Modeling Support

日食是一种独特的天体现象，为探索太阳流量减少对电离层的影响提供了极好的机会。当月球的阴影横扫毗邻的美国时，它为研究电离层提供了一个天然的实验室--电离层是我们大气中的一个部分电离区域，在无线电通信、导航和太空天气中发挥着关键作用。在日食期间，太阳辐射的减少导致电离的减少。研究人员计划通过协调多台仪器对电离层参数的观测，利用2024年即将到来的日食。拟议的工作将加深我们对电离层-热层(IT)系统中的化学和动力学过程的理解。此类事件会影响等离子体密度，从而对高频(HF：3-30 MHz)传播和通信信号产生不利影响。虽然对IT响应的宏观影响已经很好地了解了，但控制电离层密度的详细特征，包括在F区和上部电离层的传输仍然不清楚。该项目将加强与公民科学界的合作，支持两名职业生涯早期的科学家和一名本科生暑期学生。该项目通过提高通信可靠性、增强空间天气预报、支持STEM领域的教育和多样性而造福社会。该提议的主要目标之一是了解和量化外力对2023年10月和2024年4月日食的电离层密度响应的相对重要性，并将结果与2017年8月的日食进行比较。该提案将侧重于以下科学主题：1.日食驱动的电离层变化的量化：该项目试图了解日食如何影响电离层的电子密度。它计划调查F区高度(HmF2)的变化和电离层G条件(其中NmF1≥NmF2)的发生，(2)控制因素的确定：通过分析地面高频设施的数据，研究人员将量化决定电离层反应的各种因素的相对重要性，这些因素包括极紫外光通量减少、热层风、光电子传输和加热。拟议的科学调查涉及使用SuperDARN、米尔斯通-希尔非相干散射雷达(MHISR)和HamSCI高频观测。这项工作鼓励年轻一代的培训和教育，并通过早期职业科学家的参与促进能力建设。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。

Solar eclipses are unique celestial phenomena that offer excellent opportunity to explore the impacts of reduced solar flux on the ionosphere. As the moon’s shadow sweeps across the contiguous United States, it provides a natural laboratory to study the ionosphere—a partially ionized region of our atmosphere that plays a crucial role in radio communication, navigation, and space weather. During a solar eclipse, the reduction in solar radiation leads to a decrease in ionization. The investigators plan to take advantage of the upcoming solar eclipse in 2024 through coordinated multi-instruments observations of ionospheric parameters. The proposed work will deepen our understanding of the chemical and dynamical processes in the ionosphere-thermosphere (IT) system. Such events impact the plasma density, which adversely affects High Frequency (HF: 3-30 MHz) propagation and communication signals. While the macroscopic effects on the IT response are well understood, the detailed features controlling the ionospheric density including the transport in the F-region and topside ionosphere remain unclear. The project will strengthen collaborations with the citizen science community, support two early-career scientists and an undergraduate summer student. This project benefits society by improving communication reliability, enhancing space weather predictions, and supporting education and diversity in STEM fields.One of the main objectives of the proposal is to understand and quantify the relative importance of external forces on the ionospheric density responses to the October 2023 and April 2024 solar eclipses as observed by HF sounding and compare the findings with the August 2017 solar eclipse. The proposal will focus on the following scientific topics: 1. Quantification of Eclipse-Driven Ionospheric Changes: the project seeks to understand how solar eclipses impact the ionosphere's electron density. It plans to investigate variations in the F-region height (HmF2) and the occurrence of the ionospheric G-condition (where NmF1≥NmF2), (2) Identification of Controlling Factors: By analyzing data from ground-based HF facilities, the researchers will quantify the relative importance of various factors in determining the ionospheric responses, including reduced EUV Flux, thermospheric winds, photoelectron transport and heating. The proposed scientific investigation involves the use of the SuperDARN, the Millstone Hill Incoherent Scatter Radar (MHISR), and HamSCI HF observations. This work encourages training and education of the younger generation and facilitates capacity building through the involvement of early career scientists.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.