On the temporal fluctuations of pulsating auroral luminosity
On the temporal fluctuations of pulsating auroral luminosity
复制标题
关于脉动极光光度的时间波动
DOI：
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发表时间：
1988
期刊：
影响因子：
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通讯作者：
Tatsundo Yamamoto
中科院分区：
文献类型：
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作者：
Tatsundo Yamamoto
对全天电视记录的研究表明，脉动极光的亮度波动可以用一系列脉冲来理解，这些脉冲以爆发的方式快速开关，并且连续脉冲的宽度（脉动时间）相当恒定。这是常见的，即使当亮度波动由复杂的不规则变化组成时，与脉动的关闭时间相比，这是显著变化的。复杂的不规则变化被认为是由于更多的脉动斑块同时出现，在该地点上表现出向东和向西的运动，并且每个斑块主要显示孤立的亮度脉冲。给出了几个例子并对其进行了详细描述。这些观测的一个自然结果是，经典的周期概念没有多大意义，光度波动应被视为一系列单独的孤立脉冲，其中对时间的脉动是最基本的量。本文简要讨论了这些特性与磁层中VLF/ELF波粒相互作用的关系。然后对非线性弛豫振荡模型提出了新的解释，其中VLF/ELF波在磁层赤道面附近低能质不规则中的传播效应对产生更快速的高能电子通量的开关起着至关重要的作用。电磁波和静电波都可能与降水脉动有关。«少
From a study of all-sky TV records, it is shown that the luminosity fluctuations of pulsating auroras can be understood in terms of a series of pulses with rapid on-off switchings in burstlike fashion and that the widths of successive pulses (pulsation on times) are fairly constant. This is common even when luminosity fluctuations consist of complex-irregular variations, in contrast to the pulsation off time that is significantly variable. Complex-irregular variations are ground to be due to simultaneous appearance of more pulsating patches that exhibit movements eastward and westward over the site, and each of the patches shows primarily isolated luminosity pulses. Several examples are presented and described in detail. A natural consequence of these observations is that the classical concept of period does not mean much and the luminosity fluctuations should be treated as a series of individual isolated pulses where the pulsation on time is the most essential quantity. These characteristics are briefly discussed in relation to VLF/ELF wave-particle interactions in the magnetosphere. Then a new interpretation of the nonlinear relaxation oscillation model is proposed, where the propagation effect of VLF/ELF waves in low energy plasm irregularities near the magnetospheric equatorial plane plays an essential role to producemore » rapid on-off switchings of precipitating energetic electron fluxes. Both electromagnetic and electrostatic waves are possibly related to the precipitation pulsations.« less