On the Persistent Shape and Coherence of Pulsating Auroral Patches
On the Persistent Shape and Coherence of Pulsating Auroral Patches
复制标题
脉动极光斑的持续形状和相干性
DOI：
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
M. Samara
中科院分区：
文献类型：
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作者：
B. K. Humberset;J. Gjerloev;I. Mann;R. Michell;M. Samara
脉动的极光覆盖了广泛的波动形状，这些形状没有得到很好的描述。因此，本文的目的是对脉动极光斑块保持其形状、漂移和一致起伏的程度提供客观和定量的测量。我们给出了使用全天相机仔细分析脉动极光斑块的结果。我们已经确定了我们在补丁参照系中遵循的四个定义良好的单独补丁。通过这种方式，我们避免了使火箭和卫星测量复杂化的时空模糊性。我们发现贴片的形状非常持久，85%-100%的贴片重复4.5-8.5min。三个最大的斑块中的每一个都具有与距离负相关的时间相关性，因此不会以一致的方式波动。补丁内的延时响应表明所谓的流模式可能解释了不一致性。这些斑块的漂移似乎与SuperDARN确定的E→×B→对流速度不同。然而，在不旋转的坐标系中，斑块向北漂移230-287m/S，这是对流回流的典型情况。
The pulsating aurora covers a broad range of fluctuating shapes that are poorly characterized. The purpose of this paper is therefore to provide objective and quantitative measures of the extent to which pulsating auroral patches maintain their shape, drift and fluctuate in a coherent fashion. We present results from a careful analysis of pulsating auroral patches using all‐sky cameras. We have identified four well‐defined individual patches that we follow in the patch frame of reference. In this way we avoid the space‐time ambiguity which complicates rocket and satellite measurements. We find that the shape of the patches is remarkably persistent with 85–100% of the patch being repeated for 4.5–8.5 min. Each of the three largest patches has a temporal correlation with a negative dependence on distance, and thus does not fluctuate in a coherent fashion. A time‐delayed response within the patches indicates that the so‐called streaming mode might explain the incoherency. The patches appear to drift differently from the SuperDARN‐determined E→×B→ convection velocity. However, in a nonrotating reference frame the patches drift with 230–287 m/s in a north eastward direction, which is what typically could be expected for the convection return flow.
以高时间分辨率测量脉动极光的能量、通量和亮度的变化
影响因子：
1.9
作者：
Dahlgren H
通讯作者：
Dahlgren H