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

高频 (HF) 加热期间电离层中的低频波及其对地面和磁层的影响

• 批准号: 1158206
• 负责人: A Surjalal Sharma
• 金额: $ 30万
• 依托单位: University of Maryland, College Park
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1158206&HistoricalAwards=false
• 关键词: Low; Frequency; Waves; Ionosphere; During

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.

该项目的目标是发展电离层加热过程中低频波的理论、建模和模拟。一个关键焦点将是中纬度电离层，特别是即将使用阿雷西博设施进行的加热实验，并在阿根廷的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大范围的物理过程。电离层修改实验表明，在自然流系统、电喷射存在的情况下会产生低频波，而最近的结果表明，即使在不存在自然流系统和电喷射的情况下也会产生低频波。 将使用三个模拟代码：第一个模拟高纬度地区的低频波和相关过程，具有近乎垂直的磁场。第二个代码是为磁场的一般方向而设计的，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。模拟还将探索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，并将成为本研究的重点。这些努力将通过阐明连接微观和宏观尺度现象的主要过程来开发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的天然实验室，特别是各种等离子体现象。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天气相关的电离层过程。研究生将接受电离层等离子体物理学和大规模数值模拟的培训。本科生和高中生，包括来自代表性不足的少数群体的几名学生，将参与该项目并获得直接的经验和对追求科学技术的鼓励。