Low Frequency Waves in the Ionosphere During High Frequency (HF) Heating and Effects on the Ground and in the Magnetosphere

该项目的目标是发展电离层加热期间低频波的理论、建模和模拟。一个主要重点将是中纬度电离层，特别是即将利用阿雷西博设施进行的加热实验，并在阿根廷共轭区域进行协调测量。调制高频波对电离层等离子体的加热导致了尺度范围很广的物理过程。电离层改造实验表明，在存在自然电流系统、电射流的情况下会产生低频波，最近的结果表明，即使在没有电射流的情况下也会产生波。 将使用三个模拟代码：第一个用于模拟高纬度地区的低频波和相关过程，具有几乎垂直的磁场。第二个代码是为磁场的一般方向设计的，将用于中纬度地区的研究。第三个代码将具有一般的磁场几何形状，并将模拟中纬度地区及其与高纬度和低纬度地区的耦合，包括对共轭地区的影响。这些模拟还将探讨低纬度电离层加热过程中低频波的产生。中尺度现象在电离层加热过程中至关重要，将是本研究的重点。这些努力将有助于通过阐明在微观和宏观尺度上连接这些现象的主要过程，开发一个全面的电离层加热模型。加热实验允许使用电离层作为探索基本过程，特别是各种等离子体现象的自然实验室。这项工作将有助于更好地了解与电信和卫星技术以及空间气象有关的电离层过程。一名研究生将接受电离层等离子体物理学和大规模数值模拟方面的培训。本科生和高中生，包括一些来自代表性不足的少数群体的学生，将参加该项目，并获得直接的经验和鼓励，以追求科学和技术。

The objective of this project is to develop theory, modeling and simulations of low frequency waves during ionospheric heating. A key focus will be the midlatitude ionosphere, and in particular, the upcoming heating experiments using the Arecibo facility, with coordinated measurements at its conjugate region in Argentina. The heating of the ionospheric plasma by modulated high frequency waves leads to physical processes with a wide range of scales. Ionospheric modification experiments have shown the generation of low frequency waves in the presence of the natural current systems, the electrojets, and recent results show the wave generation even in their absence. Three simulation codes will be used: the first for simulations of low frequency waves and associated processes in the high-latitude region, with a nearly vertical magnetic field. The second code is designed for a general orientation of the magnetic field and will be used for studies of the mid-latitude region. The third code will have a general magnetic field geometry and will simulate the mid-latitude region and its coupling to the high- and low-latitudes, including the effects on the conjugate region. The simulations will also explore the generation of low frequency waves during heating of the low-latitude ionosphere. Meso-scale phenomena are critical during ionospheric heating and will be the focus of this research. These efforts will enable the development of a comprehensive ionospheric heating model by elucidating the leading processes that bridge the phenomena at micro- and macro-scales. The heating experiments allow the use of the ionosphere as a natural laboratory for exploring fundamental processes, in particular a variety of plasma phenomena. This work will lead to a better understanding of ionospheric processes which are relevant to telecommunications and satellite technologies, as well as space weather. A graduate student will be trained in the plasma physics of the ionosphere and large-scale numerical simulations. Undergraduate and high school students, including several from under-represented minority groups, will participate in the project and gain direct experience and encouragement to pursue science and technology.