Ion Acoustic Wave Turbulence in Ionospheric Plasmas

电离层等离子体中的离子声波湍流

• 批准号: 9016235
• 负责人: Min-Chang Lee
• 金额: $ 10.78万
• 依托单位: Massachusetts Institute of Technology
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-06-01 至 1993-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9016235&HistoricalAwards=false
• 关键词: Ion; Acoustic; Wave; Turbulence; Ionospheric

This study will investigate a source mechanism generating ion acoustic wave turbulence in the topside ionosphere that can cause strong backscatter radar echoes leading to false satellite detection signals. Theoretical investigation of the problem will be conducted at MIT, while field experiments are planned at the Arecibo Observatory to simulate the ionospheric conditions for the generations of ion acoustic wave turbulence. The proposed source mechanism is a nonlinear mode coupling process whereby Langmuir waves induced by particle precipitation can interact nonlinearly to produce ion acoustic mode waves. Detailed formulation of this nonlinear interaction process will be carried out, incorporating realistic energy spectra of high particles with a numerical analysis. In the simulation experiments at Arecibo, the VLF waves induced in the ionosphere by the HF heater are expected to cause the pitch angle scattering of originally trapped electrons in the radiation belts. These suprathermal electrons precipitated into the ionosphere along the earth's magnetic field will form a potential source producing large amplitude ion acoustic waves. Both the 430 MHz and 50 MHz radars will be employed to diagnose the ionoaphere over Aercibo. The Aercibo experiments will be conducted primarily in the 1991 ionosphere heating campaign for the dedicated research program.

本研究将探讨一个源机制产生 在顶部电离层中的离子声波湍流， 导致强烈的后向散射雷达回波， 检测信号 对这个问题的理论研究将 在麻省理工学院进行，而实地实验计划在 阿雷西沃天文台模拟电离层条件 离子声波湍流的产生。 拟议 源机制是非线性模式耦合过程， 粒子沉淀诱导的朗缪尔波可以相互作用 非线性地产生离子声模波。 详细 这种非线性相互作用过程的公式将进行 结合了高能粒子的真实能谱 进行数值分析。 在模拟实验中， 阿雷西博，高频在电离层中引起的甚低频波 加热器预计会导致俯仰角散射 最初被困在辐射带中的电子。 这些 超热电子沿着沿着 地球的磁场将形成一个潜在的来源， 大振幅离子声波 430 MHz和50 MHz 雷达将用于诊断Aercibo上空的电离层。 Aercibo实验将主要在1991年进行。 电离层加热运动的专门研究计划。