Simultaneous images of the northern and southern auroras from the Polar spacecraft: An auroral substorm
Simultaneous images of the northern and southern auroras from the Polar spacecraft: An auroral substorm
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极地航天器同步拍摄的南北极光图像：极光亚暴
DOI：
10.1029/2002ja009356
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发表时间：
2003
影响因子：
--
通讯作者：
J. Sigwarth
中科院分区：
文献类型：
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作者：
L. Frank;J. Sigwarth
[1]用极地航天器上的地球照相机用一台照相机首次同时获得了北方和南半球极光的图像，该照相机具有足够的角分辨率，可以提供强度图。2001年11月1日，当航天器处于有利位置以观测两个极光时，偶然观测到了极光亚暴。在极光的爆发和早期扩张阶段的强度映射到校正的地磁坐标。在远紫外波长处的开始增亮首先在南部极光中被检测到，随后在北方极光中被观察到，大约1分钟后在大约5 RE的L-壳层上。在极光扩张阶段的早期阶段，南部极光继续变得更加明亮。两半球极光强度的不相等表明电离层和磁层之间存在着强耦合。对极光的测绘显示，两个起始位置之间存在约40分钟的当地时差，南部的极光相对于北部的极光位于东部。这种位移也类似地检测到在安静的极光区，这是没有参与极光亚暴。这种位移可能有助于提高全球磁性模型的准确性，这对于确定磁层中的现场粒子和场测量的位置至关重要。首先由飞机在两个半球的可见光波段观测报告的北方平静时间极光的亮度增加了百分之几十，这一点已经被极地航天器的更全面的观测所证实。
[1] The first simultaneous images of the auroras in the Northern and Southern Hemispheres with a single camera have been gained with the Earth Camera onboard the Polar spacecraft with sufficient angular resolution to provide maps of the intensities. An auroral substorm was fortuitously observed on 1 November 2001 when the spacecraft was favorably positioned to observe both auroras. The auroral intensities during the onset and the early expansive phase were mapped into corrected geomagnetic coordinates. The onset brightening at far-ultraviolet wavelengths was first detected in the southern auroras and subsequently seen in the northern auroras about 1 min later on L-shells of about 5 RE. During the early phases of the auroral expansive phase, the southern aurora continued to be brighter. The unequal auroral intensities in the two hemispheres suggest that there is strong coupling of the ionosphere and magnetosphere. The mapping of the auroras revealed that there is a local time difference between the onset positions of about 40 min, with the southern auroras positioned to the east relative to those in the north. This displacement was also similarly detected in the quiet auroral regions, which were not participants in the auroral substorm. Such displacements may be useful in developing improvements in the accuracy of global magnetic models that are important for determination of the position of the in situ particle and field measurements in the magnetosphere. The greater brightness of the northern quiet time auroras by tens of percent as first reported by aircraft observations at visible wavelengths in both hemispheres has been verified by the more global view from the Polar spacecraft.