Statistical Study of Ejections in Coronal Hole Regions As Possible Sources of Solar Wind Switchbacks and Small-scale Magnetic Flux Ropes
Statistical Study of Ejections in Coronal Hole Regions As Possible Sources of Solar Wind Switchbacks and Small-scale Magnetic Flux Ropes
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DOI：
10.3847/2041-8213/acc0f1
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发表时间：
2023-03
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影响因子：
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通讯作者：
Nengyi Huang;Sophia D’Anna;Haimin Wang
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作者：
Nengyi Huang;Sophia D’Anna;Haimin Wang
帕克太阳探测器（PSP）在太阳风中观测到了“之字形”（SBs）和小尺度磁通绳（SMFRs）等普遍存在的瞬态波动，但其来源尚不清楚。可能的候选者分为两类：太阳起源和太阳风中的原位生成。在各种太阳起源情景中，太阳风起源的冕洞（CH）区域的小尺度活动（如喷射和喷发）被认为是候选者。利用太阳动力学天文台大气成像组件上的全磁盘极紫外图像，我们在PSP遭遇5，7和8期间识别CH区域的小尺度喷射，并研究其统计特性。这些喷射属于两类：标准射流和井喷射流。在24天内确定了27，832次喷射（其中约2/3是井喷喷射），我们更新了PSP的预期频率，以检测日光空间中的对应物。我们发现的喷射与PSP检测到的SMFR的频率相当，但它们不足以作为SB或SB贴片的唯一生产者。这项研究遗漏的某些较小的事件，如小喷流，可能会填补差距。
The omnipresence of transient fluctuations in the solar wind, such as switchbacks (SBs) and small-scale magnetic flux ropes (SMFRs), have been well observed by the in situ observation of Parker Solar Probe (PSP), yet their sources are not clear. Possible candidates fall into two categories: solar origin and in situ generation in the solar wind. Among the solar-origin scenarios, the small-scale activities (such as ejections and eruptions) in coronal hole (CH) regions, where solar wind originates, are suggested as candidates. Using full-disk extreme ultraviolet images from Atmospheric Imaging Assembly on board the Solar Dynamic Observatory, we identify small-scale ejections in CH regions during PSP Encounters 5, 7, and 8, and study their statistical properties. These ejections belong to two categories: standard jets and blowout jets. With 27,832 ejections identified in 24 days (about 2/3 of them are blowout jets), we updated the expected frequency for PSP to detect their counterparts in the heliospace. The ejections we identified are comparable to the frequency of PSP-detected SMFRs, but they are insufficient to serve as the only producer of SBs or SB patches. Certain smaller events missed by this study, such as jetlets, may fill the gap.