Multiple, distant (40°) in situ observations of a magnetic cloud and a corotating interaction region complex
Multiple, distant (40°) in situ observations of a magnetic cloud and a corotating interaction region complex
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DOI：
10.1016/j.jastp.2010.09.011
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发表时间：
2011-06-20
影响因子：
1.9
通讯作者：
Sauvaud, J. A.
中科院分区：
文献类型：
--
作者：
Farrugia, C. J.;Berdichevsky, D. B.;Sauvaud, J. A.
我们报告了对 2007 年 11 月 19 日至 21 日在日光层电流片 (HCS) 附近发生的磁云 (MC) 和共转相互作用区域 (CIR) 之间复杂相互作用的 Wind 和 STEREO 探测器（STA、STB）进行的现场观测的综合分析。探测器间隔 0.7 AU（接近 40 度），在日照纬度上分布（4.8 度） STB、Wind 和 STA 分别为 2.2 度和 -0.4 度）。我们在 Wind 上使用来自 MFI、SWE 和 3DP 仪器的数据，在 STEREO 上使用来自 PLASTIC 和 IMPACT 套件的数据。位于地球东部的 STB 观测到了前向激波，随后出现了 MC 的特征。 MC 扮演了 HCS 的角色，因为退出时的行星际磁场 (IMF) 极性与进入时的极性相反。观察到穿过血浆片的通道。沿着日地线，风观察到了正向激波和反向激波之间的流界面（SI）。由 CIR 压缩的 MC 被夹带其中。 STA位于地球以西20°处，看到了一次MC，但之前没有发生过地震。 SI 跟随瞬变。使用各种方法检查冲击，并由此得出结论，Wind 处的前向冲击（而非 STB 处）是由 MC 驱动的。通过 Grad-Shafranov 重建检查 MC，我们发现 Wind 和 STA 处以及 STB 处可能存在双磁通绳结构的证据。这些方向与在三个航天器上观察到的大型通量管的概念不一致。我们发现这与太阳风“斯特拉尔”电子的方向特性是一致的。我们检查了地磁响应的各个方面，并发现了与两个行星际触发器相对应的双倾风暴。由于相互作用，最小 Dst 相位被延长，并且地球效应被加剧。我们的结论是，虽然复合流的形成是行星际空间的一个共同特征，但在涉及 CIR 时了解它们的组成是一个复杂的问题，需要数值模拟和/或更多的现场观测才能完全阐明。 (C) 2010 Elsevier Ltd. 保留所有权利。
We report a comprehensive analysis of in situ observations made by Wind and the STEREO probes (STA, STB) of a complex interaction between a magnetic cloud (MC) and a corotating interaction region (CIR) occurring near the heliospheric current sheet (HCS) on November 19-21, 2007. The probes were separated by 0.7 AU (similar to 40 degrees) with a spread in heliographic latitudes (4.8,degrees 2.2,degrees and -0.4,degrees for STB, Wind and STA, respectively). We employ data from the MFI, SWE and 3DP instruments on Wind, and the PLASTIC and IMPACT suites on STEREO. STB, located east of Earth, observed a forward shock followed by signatures of a MC. The MC took the role of the HCS in that the polarity of the interplanetary magnetic field (IMF) on exit was the reverse of that on entry. A passage through a plasma sheet was observed. Along the Sun-Earth line Wind observed a stream interface (SI) between a forward and a reverse shock. A MC, compressed by the CIR, was entrained in this. STA, located 20 to the west of Earth, saw a MC which was not preceded by a shock. A SI trailed the transient. The shocks are examined using various methods and from this it is concluded that the forward shock at Wind-but not at STB-was driven by the MC. Examining the MC by Grad-Shafranov reconstruction, we find evidence of a double-flux rope structure at Wind and STA and possibly also at STB. The orientations are at variance with the notion of a large-scale flux tube being observed at the three spacecraft. We find consistency of this with the directional properties of the solar wind "strahl" electrons. We examine aspects of the geomagnetic response and find a double-dip storm corresponding to the two interplanetary triggers. The minimum Dst phase was prolonged and the geoeffects were intensified due to the interaction. We conclude that while the formation of compound streams is a common feature of interplanetary space, understanding their components when CIRs are involved is a complicated matter needing numerical simulations and/or more in situ observations for its complete elucidation. (C) 2010 Elsevier Ltd. All rights reserved.