Global analysis of three traveling vortex events during the November 1993 storm using the assimilative mapping of ionospheric electrodynamics technique
Global analysis of three traveling vortex events during the November 1993 storm using the assimilative mapping of ionospheric electrodynamics technique
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使用电离层电动力学技术同化绘图对 1993 年 11 月风暴期间的三个行涡事件进行全球分析
DOI：
10.1029/97ja03433
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发表时间：
1998
期刊：
影响因子：
--
通讯作者：
C. Clauer
中科院分区：
文献类型：
--
作者：
A. Ridley;T. Moretto;P. Ernström;C. Clauer
本文利用电离层电动力学同化成图技术研究了1993年11月3日至11日的三个移动涡旋事件，以解释全球台站的地磁响应。当AMIE势图形被高通滤波时，观察到清晰的涡旋结构。AMIE输出与地面磁力数据相比相当不错，尽管AMIE倾向于平滑结构。单涡观察到形成近1000 MLT和传播到1400 MLT，在格陵兰磁力计和整个中午。在70° ~ 75°范围内，涡旋的速度约为4-8 km/s（0.2° ~ 0.3° s-1）。涡旋的数量以及涡旋的运动与经典的对流涡旋运动图不同。因此，我们认为，这些涡旋事件可能有不同的生成机制或发生在不同的磁层状态下，因此，它们应该被视为一个单独的事件类别。AMIE技术提供了将涡旋与大尺度对流模式联系起来的可能性。我们注意到如何涡可以解释为小规模的，快速变化的大规模对流模式，虽然这些变化显示出许多差异，以前的研究变化的大规模对流模式。我们推测，这类特殊的旅行涡旋事件可能是由在向阳面磁层顶上的分离扰动产生的，这是由磁合并的增强或减弱引起的。
We have studied three traveling vortex events during the November 3-11, 1993, storm period using the assimilative mapping of ionospheric electrodynamics technique to help interpret the ground magnetic response from a global set of stations. When the AMIE potential patterns are high-pass filtered, clear vortex structures are observed. The AMIE output compares reasonably well with the ground magnetic data, although AMIE has a tendency to smooth out the structures. Single vortices are observed to form near 1000 MLT and propagate to 1400 MLT, over the Greenland magnetometers and across noon. The velocity of the vortices is approximately 4-8 km/s (0.2° - 0.3° s -1 between 70° and 75°) eastward along a line of invariant latitude. The number of vortices, as well as the motion of the vortices, differs from the classical picture of a traveling convection vortex. We therefore suggest that these vortex events might have a different generation mechanism or occur under a different state of the magnetosphere, and thus that they should be considered a separate class of events. The AMIE technique offers the possibility to relate the vortices to the large-scale convection patterns. We note how the vortices can be interpreted as small scale, rapid changes in the large-scale convection pattern, although these changes show many differences to previous studies of changing large-scale convection patterns. We speculate that this particular class of traveling vortex event may be generated by a perturbation in the separatric on the dayside magnetopause, caused by an enhancement or depreciation of the magnetic merging.