Simultaneous Cluster and CUTLASS Observations of FTEs on 11 February 2004
Simultaneous Cluster and CUTLASS Observations of FTEs on 11 February 2004
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DOI：
10.1002/cjg2.1188
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
Qinghe Zhang;Rui-yuan Liu;Ji‐ying Huang;M. Dunlop;Hongqiao Hu;Zejun Hu;Y. Bogdanova;M. Lester
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文献类型：
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作者：
Qinghe Zhang;Rui-yuan Liu;Ji‐ying Huang;M. Dunlop;Hongqiao Hu;Zejun Hu;Y. Bogdanova;M. Lester
本文分析了2004年2月11日世界标准时间11:00至11:40期间集群航天器上的磁通门磁强计（FGM）和等离子体电子与电流实验（PEACE）以及芬兰CUTLASS雷达的同步观测。在此期间，集群航天器阵列遇到了北半球高空尖点，并于世界标准时间11:18左右穿过磁层顶进入磁鞘。所有 4 个集群航天器均观测到大量通量传递事件 (FTE)。发现这些FTE呈准周期性出现，周期约为130 s。由于所有4个集群航天器都观测到了这些FTE，我们应用四航天器技术“最小方向导数（或差异）”（MDD）和“时空差异”（STD）来计算这些FTE的维度、运动和尺度。这些 FTE 推断的向北重新连接的通量管显示为向北或东北和尾部移动，具有准二维结构和 (0.87 ~ 1.81)RE 的尺度。集群航天器在边界通过期间的电离层足迹显示在 CUTLASS 芬兰雷达视场的中心位置。结果表明，CUTLASS 数据的反向散射功率与星团足迹纬度处的磁层 FTE 同步增强。雷达中的这些雷达极光特征随后向极地传播，在高纬度地区形成经典的“向极地移动的雷达极光形态”结构。同时，FTE 运动与磁层顶表面重新连接的磁通量管的预期运动一致，磁层顶表面上的重新连接磁通量管是在主要的上游条件下由亚太阳重新连接地点产生的。
This paper analyzes the simultaneous observations of the Flux Gate Magnetometer (FGM) and Plasma Electron and Current Experiment (PEACE) on Cluster Spacecraft, and the CUTLASS Finland radar between 11:00 and 11:40 UT on 11 February 2004. In this interval, the Cluster spacecraft array encountered the northern hemisphere high altitude cusp, and crossed the magnetopause into the magnetosheath at about 11:18 UT. A large number of flux transfer events (FTEs) were observed by all 4 Cluster spacecraft. It is found that these FTEs appeared quasi-periodically with a period of about 130 s. Since all 4 Cluster spacecraft observed these FTEs, we applied the four-spacecraft techniques “Minimum Directional Derivative (or Difference)” (MDD) and “Spatio-temporal Difference” (STD) to calculate the dimension, motion and scale of these FTEs. The inferred northwardly reconnected flux tubes for these FTEs are shown to move northward or north-east and tailward with a quasi-2-D structure and a scale of (0.87 ~ 1.81)RE. The ionospheric footprint of the Cluster spacecraft during the boundary passage is shown to map centrally within the field-of-view of the CUTLASS Finland radar. It is shown that the backscatter power of CUTLASS data is enhanced in synchronously with the magnetospheric FTEs at the latitude of the Cluster footprint. These radar auroral features in the radar subsequently propagated poleward, forming classic “poleward-moving radar auroral form” structures at higher latitudes. The FTE motions meanwhile are shown to be consistent with the expected motion of reconnected magnetic flux tubes over the surface of the magnetopause, arising from a predominantly sub-solar reconnection site during the prevailing upstream conditions.