Small-scale Magnetic Flux Ropes in Stream Interaction Regions from Parker Solar Probe and Wind Spacecraft Observations
Small-scale Magnetic Flux Ropes in Stream Interaction Regions from Parker Solar Probe and Wind Spacecraft Observations
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DOI：
10.3847/1538-4357/aca894
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发表时间：
2023-01
期刊：
影响因子：
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通讯作者：
Yu Chen;Q. Hu;R. Allen;L. Jian
中科院分区：
文献类型：
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作者：
Yu Chen;Q. Hu;R. Allen;L. Jian
利用Parker太阳探测器和Wind航天器的现场测量，我们研究了流相互作用区(SIRS)内的小尺度磁通绳(SFR)及其性质。在∼为0.15~1Au的SIRS范围内，在较宽的太阳风速范围内，SFR的出现频率较高，且这些结构的Alfvénity随日心距离的增加而显著降低。此外，我们还考察了来自同一太阳源的五个相应的SIRS的变化。在这些SIRS中，超热电子的增强持续到1Au，并被多次观测到。SFR似乎反复出现在反复出现的SIRS中，并且至少被Wind航天器穿越两次。这组SFR在磁场分量、等离子体体积性质、太阳风α粒子和质子粒子密度比以及单向超热电子的变化方面具有相似之处。我们还通过详细的时间序列图和Grad-Shafrov重建结果表明，它们具有相同的手性，并携带相当数量的磁通量。最后，我们讨论了这些重现的SFR通过交换重联形成的可能性，维持与太阳的连接，并存活到1Au。
Using in situ measurements from the Parker Solar Probe and Wind spacecraft, we investigate the small-scale magnetic flux ropes (SFRs) and their properties inside stream interaction regions (SIRs). Within SIRs from ∼0.15 to 1 au, SFRs are found to exist in a wide range of solar wind speeds with more frequent occurrences after the stream interface, and the Alfvénicity of these structures decreases significantly with increasing heliocentric distances. Furthermore, we examine the variation of five corresponding SIRs from the same solar sources. The enhancements of suprathermal electrons within these SIRs persist at 1 au and are observed multiple times. An SFR appears to occur repeatedly with the recurring SIRs and is traversed by the Wind spacecraft at least twice. This set of SFRs has similarities in variations of the magnetic field components, plasma bulk properties, density ratio of solar wind alpha and proton particles, and unidirectional suprathermal electrons. We also show, through the detailed time-series plots and Grad–Shafranov reconstruction results, that they possess the same chirality and carry comparable amounts of magnetic flux. Lastly, we discuss the possibility for these recurring SFRs to be formed via interchange reconnection, maintain the connection with the Sun, and survive up to 1 au.