Simultaneous radio and optical observations of auroral structures: Implications for AKR beaming
Simultaneous radio and optical observations of auroral structures: Implications for AKR beaming
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极光结构的同步无线电和光学观测：AKR 波束的影响
DOI：
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发表时间：
2011
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通讯作者：
J. Sigwarth
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作者：
J. Menietti;R. Mutel;I. Christopher;K. A. Hutchinson;J. Sigwarth
[1]极地航天器对极光千米辐射光谱的观测，加上在源足点极光椭圆的同步光学图像，显示出与离散极光特征的强烈相关性。我们讨论了几个例子，独特的“V”形配置文件的时间频率AKR光谱的最低点通道（底部的V）的时间与航天器交叉连接到离散极光弧的场线相吻合。这些结果支持模型的AKR发射起源于密度腔与辐射最初局限于一个“切平面”，但强烈折射向上的频率依赖性的方式。推断的AKR源的空间分布与连接离散极光弧的场线非常一致，表明离散弧与相同场线上的鲁棒AKR发射高度相关，正如Gurnett（1974）几十年前首次提出的那样。
[1] Polar spacecraft observations of auroral kilometric radiation (AKR) spectra, combined with simultaneous optical images of the auroral oval at the source foot points, show a strong correlation with discrete auroral features. We discuss several examples of distinctive “V”-shaped profiles in time-frequency AKR spectra for which the time of nadir passage (bottom of V) coincides with the spacecraft crossing field lines connected to discrete auroral arcs. These results support models of AKR emission originating in density cavities with radiation initially confined to a “tangent plane” but strongly refracted upward in a frequency-dependent manner. The inferred spatial distributions of AKR sources are closely coincident with field lines connecting discrete auroral arcs, indicating that discrete arcs are highly correlated with robust AKR emission on the same field lines, as first suggested by Gurnett (1974) several decades ago.