CEDAR Postdoc: Nonlocal Effects in the Equatorial and Auroral Electrojet

本研究的目的是调查缓慢增长的不规则性，在高纬度E地区，不能准确地描述一个本地的线性不稳定，而是有一个对流，非本地的演变。这项研究将利用现有的非本地模式从高纬度扩展到中低纬度。该模型基于等离子体微扰方程的展开，沿着波作用守恒原理。在高纬度地区，以前的研究使用这个模型已经发现了一个新的机制，波的增长或衰减纯粹从波能量守恒，当波传播到一个区域的不同背景等离子体密度。在大多数情况下，这个过程被证明比传统的梯度漂移生长更重要。在低纬度地区，极化漂移导致不规则性通过垂直等离子体密度梯度垂直传播，根据波能守恒原理的增长将是一个重要的，如果不是主要的过程。这项研究将调查的过程中，并在一般情况下提高E区的不规则性的演变的理解，通过推广模型的磁场几何在低纬度和中纬度。此外，从模型的不稳定性模拟将与Jicamarca射电天文台的数据进行比较。这将有助于理解和解释E区不规则体的雷达观测。赤道电射流中的等离子体不规则性是重要的，因为它们修改了传输特性并影响E区域的平均状态，改变了电射流电流，并影响了整个低纬度和中纬度的电动力学。这些不规则性还提供了测量赤道MLT区域电场和风等参数的方法，这些参数无法以其他方式进行探测。随着我们对工作中不稳定性过程的了解的增加，这种测量的有效性也在提高。最后，自然发生的等离子体波和不稳定性的研究具有重要的意义，在封闭的实验室等离子体的研究，社会可能最终依赖作为能源。

The purpose of this study is to investigate slowly growing irregularities in the high latitude E region that cannot be described accurately by a local linear instability, but instead have a convective, nonlocal evolution. The study will make use of an extension of an existing nonlocal model from high latitudes to mid and low latitudes. The model is based on an expansion of the plasma perturbation equation, along with the principle of conservation of wave action. At high latitudes, previous research using this model has uncovered a new mechanism for wave growth or decay purely from conservation of wave energy, when a wave propagates into a region of different background plasma density. This process proved to be more important than traditional gradient drift growth in most cases. At low latitudes, where the polarization drift causes irregularities to propagate vertically through the vertical plasma density gradient, growth from the principle of conservation of wave energy will be an important, if not dominant process. This research will investigate the process, and in general improve the understanding of the evolution of E region irregularities, by generalizing the model to the magnetic field geometry at low and mid latitudes. Additionally, instability simulations from the model will be compared with Jicamarca Radio Observatory data. This will help understanding and interpretation of radar observations of E region irregularities. Plasma irregularities in the equatorial electrojet are important because they modify transport properties and affect the mean state of the E region, altering the electrojet current, and influencing electrodynamics throughout low and mid latitudes. The irregularities also provide means of measuring parameters like electric fields and winds in the equatorial MLT region that cannot be readily probed in other ways. The validity of such measurements improves as our understanding of the instability processes at work grows. Finally, the study of naturally occurring plasma waves and instabilities has important overtones for research in confined laboratory plasmas that society may eventually depend upon as energy sources.