The equatorial E-region and its plasma instabilities: a tutorial
The equatorial E-region and its plasma instabilities: a tutorial
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赤道 E 区及其等离子体不稳定性：教程
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发表时间：
2009
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通讯作者：
D. T. Farley
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作者：
D. T. Farley
在这个简短的教程中，我们首先简要回顾了赤道电离层E区的基本物理，重点是驱动等离子体不稳定性并产生易于被雷达和火箭探测器检测到的强等离子体波的强电射流电流系统。然后我们讨论不稳定性本身，包括理论和一些观测数据的例子。这些不稳定性已经被研究了大约半个世纪（！），从国际地球年开始，特别是在秘鲁的Jicamarca射电天文台。重要过程的线性流体理论现在已经很好地理解了，但是关于一些动力学效应仍然存在问题，更不用说在我们对决定我们实际观察细节的限制性非线性过程有充分的定量理解之前，还有大量的工作要做。随着我们的观测技术，特别是雷达技术的改进，我们找到了一些答案，但也发现了越来越多的问题。研究自然现象（如这些不稳定性）的一个困难是，我们无法进行主动的因果实验;我们仅限于自然提供的输入和响应。这里的一个希望是数值等离子体模拟能力的稳步增长。如果我们能够准确地模拟相关的等离子体物理，我们就可以控制输入并非常详细地测量响应。不幸的是，这个问题本质上是三维的，我们仍然需要比目前更多的计算机能力，尽管我们已经取得了很大的进展。
In this short tutorial we first briefly review the basic physics of the E-region of the equatorial ionosphere, with emphasis on the strong electrojet current system that drives plasma instabilities and generates strong plasma waves that are easily detected by radars and rocket probes. We then discuss the instabilities themselves, both the theory and some examples of the observational data. These instabilities have now been studied for about half a century (!), beginning with the IGY, particularly at the Jicamarca Radio Observatory in Peru. The linear fluid theory of the important processes is now well understood, but there are still questions about some kinetic effects, not to mention the considerable amount of work to be done before we have a full quantitative understanding of the limiting nonlinear processes that determine the details of what we actually observe. As our observational techniques, especially the radar techniques, improve, we find some answers, but also more and more questions. One difficulty with studying natural phenomena, such as these instabilities, is that we cannot perform active cause-and-effect experiments; we are limited to the inputs and responses that nature provides. The one hope here is the steadily growing capability of numerical plasma simulations. If we can accurately simulate the relevant plasma physics, we can control the inputs and measure the responses in great detail. Unfortunately, the problem is inherently three-dimensional, and we still need somewhat more computer power than is currently available, although we have come a long way.