Investigations of the HF Ionospheric Modification Process at Arecibo

PI将侧重于使用阿雷西博附近升级的高频设施对F区电离层进行高频无线电波修改。他将特别关注电离层介质中的基波-等离子体相互作用，以及利用受控电离层扰动来阐明自然大气过程。研究将与太阳黑子周期同步进行，以便可以在两种不同的电离层环境中进行实验：夜间，夏季电离层(为受控实验提供高度稳定的等离子体)，以及夜间，冬季电离层(低碰撞损失率导致大尺度温度/电子密度修正)。PI将研究的基本等离子体过程包括朗缪尔振荡和离子波的共振激发，因此他可以在高频束在冷的未修改的等离子体中开启后的50毫秒交互间隔内全面探索波-等离子体相互作用。他将通过研究高频引起的等离子体不规则性/结构如何影响波的传播和改变等离子体湍流的演化路径，将当前的理论推进到修改的前50毫秒之外。PI将研究具有高频诱导扰动的夜间电离层中的等离子体传输现象和弹性/非弹性电子碰撞频率。该项目提出的一系列观测将主要在阿雷西博进行，但有来自GRI的补充处理器。

The PI will focus on high-frequency (HF) radio wave modification of the F-region ionosphere using the upgraded HF facility near Arecibo. He will pay particular attention to fundamental wave-plasma interactions in the ionospheric medium and the use of controlled ionospheric perturbations to elucidate natural aeronomic processes. The research will be timed with the solar sunspot cycle so that experiments can be performed in two distinct ionospheric environments: the nighttime, summer ionosphere (providing a highly stable plasma for controlled experimentation), and the nighttime, winter ionosphere (low collisional loss rates give rise to macroscale temperature/electron density modifications). Basic plasma processes the PI will address include the resonant excitation of Langmuir oscillations and ion waves, so he can fully explore wave-plasma interactions in the 50-ms interaction interval following turn-on of the HF beam in a cold unmodified plasma. He will advance current theories beyond the first 50 ms of modification by investigating how HF-induced plasma irregularities/structures impact wave propagation and altering the evolutionary path of the plasma turbulence. The PI will examine plasma transport phenomena and elastic/inelastic electron collision frequencies in the nighttime ionosphere with HF-induced perturbations. The array of observations this project proposes will be made mainly at Arecibo, but with supplementary processors from GRI.