CEDAR: Auroral Electrojet Waves and Wave Heating

高纬度极光降水的重要影响之一是在电离层中产生波动和湍流。这些动态变化可能会对通过电离层的通信和导航信号造成干扰和退化。尽管在75多年前就在极光区域发现了电离层的不规则性，但关于波在湍流状态下传播和饱和的基本问题仍然存在。该奖项的目的是研究一种被称为法利-邦曼波的特殊湍流。其目的是研究这些波的内部机制，它们对背景电离层状态的影响，以及从它们接收到的相干雷达后向散射的解释。这项调查有实验、理论和模型方面的内容，也有很强的教育基础。这项研究的广泛目标是阐明磁层强迫(上图)产生电离层结构所涉及的过程，这是《2013年太阳和空间物理十年概览》强调的两个主要主题之一。它强调在扰动条件下可获得的背景强迫、其造成的极光不稳定和湍流以及对平均电离层状态的反馈之间的多尺度联系，构成了这一复杂和高度耦合过程的系统方法。这项拟议的研究将由康奈尔大学和阿拉斯加大学安克雷奇分校的教职员工和学生进行，并将涉及到阿拉斯加的实验田野工作。实验数据将在理论研究结果的背景下进行解释。这项研究的一个组成部分是建立一个能够模拟中小尺度波动力学的法利-邦曼波的3D混合流体动力学模型。第二部分基于随机微分方程组(SDE)的形式，建立了一个包含饱和效应的Farley-Buneman波和湍流的数学模型。这项调查的更广泛影响与将要开发的工具的新颖性有关，这些工具在雷达极光的研究之外具有应用。雷达成像作为在地球空间进行发现研究的一种手段具有巨大的潜力，但计算要求很高，在它得到简化和加速之前，目前的努力之外几乎不会有什么应用。其他更广泛的影响将来自康奈尔大学和阿拉斯加大学地球航天和雪松科学的本科生和研究生教育。

One of the important effects of auroral precipitation at high latitudes is the production of waves and turbulence in the ionosphere. These dynamic variations can cause disruption and degradation of communication and navigation signals that pass through the ionosphere. Although ionospheric irregularities were discovered in the auroral zone more than 75 years ago, fundamental questions about the way that the waves propagate and saturate in a turbulent state persist. The purpose of this award is to investigate a particular kind of turbulence referred to as Farley-Buneman waves. The objective is to study the internal mechanics of these waves, their effects on the background ionospheric state, and the interpretation of coherent radar backscatter that can be received from them. The investigation has experimental, theoretical, and modeling aspects as well as strong educational underpinnings. The broad goal of the research is to elucidate the processes involved in generating ionospheric structure by magnetospheric forcing (from above), one of the two main themes highlighted by the 2013 Decadal Survey for Solar and Space Physics. Its emphasis on the multiscale connections between the background forcing available during disturbed conditions, the auroral instability and turbulence it creates, and the feedback on the mean ionospheric state constitutes a systems approach to this complex and highly coupled process. The proposed study will be carried out by faculty and students at Cornell University and the University of Alaska, Anchorage, and will involve experimental field work in Alaska. Experimental data will be interpreted in the context of results from the theoretical investigation. One component of that investigation involves the construction of a 3D hybrid fluid-kinetic model of Farley- Buneman waves capable of simulating the wave mechanics at small and intermediate scales. The second component involves the development of a mathematical model of Farley-Buneman waves and turbulence, including saturation effects, based on the formalism of stochastic differential equations (SDEs). The broader impact of this investigation is associated with the novelty of the tools that will be developed, which have applications outside research in the radar aurora. Radar imaging has tremendous potential as a means of performing discovery research in geospace but is computationally demanding and will see little application outside the current effort until it can be simplified and accelerated. Additional broader impact will come from undergraduate and graduate education in geospace and CEDAR science at Cornell and the University of Alaska.