Magnetic Field Restructuring Associated With Two Successive Solar Eruptions

Wang, Rui; Liu, Ying D.; Yang, Zhongwei; Hu, Huidong

doi:10.1088/0004-637x/791/2/84

Cited by 34 publications

(30 citation statements)

References 27 publications

(37 reference statements)

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“…In 2015 June AR 12371 exhibited elevated activity, somewhat similar to AR 11429 in 2012 March (Liu et al 2013(Liu et al , 2014cWang et al 2014;Sun et al 2015). The active region produced a CME of about 1200 km s −1 associated with an M3.0 flare from N13 • E45 • that peaked at 17:36 UT on June 18, a CME of about 1300 km s −1 associated with an M2.0 flare from N12 • E13 • peaking at 01:42 UT on June 21, a CME of about 1000 km s −1 associated with an M6.5 flare from N13 • W05 • peaking at 18:23 UT on June 22, and another one of about 1700 km s −1 associated with an M7.9 flare from N10 • W42 • peaking at 08:16 UT on June 25.…”

Section: The 2015 June Eventmentioning

confidence: 81%

Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability

Liu

Wang

et al. 2015

ApJ

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105

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The largest geomagnetic storms of solar cycle 24 so far occurred on 2015 March 17 and June 22 with D st minima of −223 and −195 nT, respectively. Both of the geomagnetic storms show a multi-step development. We examine the plasma and magnetic field characteristics of the driving coronal mass ejections (CMEs) in connection with the development of the geomagnetic storms. A particular effort is to reconstruct the in situ structure using a Grad-Shafranov technique and compare the reconstruction results with solar observations, which gives a larger spatial perspective of the source conditions than one-dimensional in situ measurements. Key results are obtained concerning how the plasma and magnetic field characteristics of CMEs control the geomagnetic storm intensity and variability: (1) a sheath-ejecta-ejecta mechanism and a sheath-sheath-ejecta scenario are proposed for the multi-step development of the 2015 March 17 and June 22 geomagnetic storms, respectively; (2) two contrasting cases of how the CME flux-rope characteristics generate intense geomagnetic storms are found, which indicates that a southward flux-rope orientation is not a necessity for a strong geomagnetic storm; and (3) the unexpected 2015 March 17 intense geomagnetic storm resulted from the interaction between two successive CMEs plus the compression by a high-speed stream from behind, which is essentially the "perfect storm" scenario proposed by Liu et al. (2014a, i.e., a combination of circumstances results in an event of unusual magnitude), so the "perfect storm" scenario may not be as rare as the phrase implies.

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Section: The 2015 June Eventmentioning

confidence: 81%

Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability

Liu

Wang

et al. 2015

ApJ

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105

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“…Two of the main sources of successive CMEs are homologous and sympathetic eruptions. Solar observations have revealed that recurrent CMEs occur from the same active region, often associated with homologous flares (Schmieder et al 1984;Moon et al 2003;Liu et al 2014a,b;Wang et al 2014a). Sympathetic CMEs, when the eruption of one CME triggers another, is another source of successive CMEs in relatively close angular and temporal separation (see Fig.…”

Section: Plasma Evolutionmentioning

confidence: 98%

The Physical Processes of CME/ICME Evolution

et al. 2017

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As observed in Thomson-scattered white light, coronal mass ejections (CMEs) are manifest as large-scale expulsions of plasma magnetically driven from the corona in the most energetic eruptions from the Sun. It remains a tantalizing mystery as to how these erupting magnetic fields evolve to form the complex structures we observe in the solar wind at Earth. Here, we strive to provide a fresh perspective on the post-eruption and interplanetary evolution of CMEs, focusing on the physical processes that define the many complex interactions of the ejected plasma with its surroundings as it departs the corona and propagates through the heliosphere. We summarize the ways CMEs and their interplanetary CMEs (ICMEs) are rotated, reconfigured, deformed, deflected, decelerated and disguised during their journey through the solar wind. This study then leads to consideration of how structures originating in coronal eruptions can be connected to their far removed interplanetary counterparts. Given that ICMEs are the drivers of most geomagnetic storms (and the sole driver of extreme storms), this work provides a guide to the processes that must be considered in making space weather forecasts from remote observations of the corona.

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“…They include several major flares from well-studied ARs. Among others, NOAA AR 11158 produced the first Xclass (X2.2) flare in Solar Cycle 24 (e.g., Schrijver et al 2011), 11429 produced the largest (X5.4) flare so far in this cycle (e.g., Wang et al 2014), 12017 produced the "best-observed" X1.0-class flare (e.g., Kleint et al 2015), and 12192, the largest sunspot group so far in the cycle, produced many (6 X-and 24 M-class) but CMEpoor events (e.g., Sun et al 2015: 4 X-and 2 M-class events are listed in Table 1). Almost all the events in this table occurred at PILs within the AR's magnetic structure itself.…”

Section: Properties Of Ars and Flare Eventsmentioning

confidence: 99%

Magnetic Properties of Solar Active Regions That Govern Large Solar Flares and Eruptions

Toriumi

Schrijver

Harra³

et al. 2017

ApJ

160

123

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Solar flares and coronal mass ejections (CMEs), especially the larger ones, emanate from active regions (ARs). With the aim to understand the magnetic properties that govern such flares and eruptions, we systematically survey all flare events with GOES levels of ≥ M5.0 within 45• from disk center between May 2010 and April 2016. These criteria lead to a total of 51 flares from 29 ARs, for which we analyze the observational data obtained by the Solar Dynamics Observatory. More than 80% of the 29 ARs are found to exhibit δ-sunspots and at least three ARs violate Hale's polarity rule. The flare durations are approximately proportional to the distance between the two flare ribbons, to the total magnetic flux inside the ribbons, and to the ribbon area. From our study, one of the parameters that clearly determine whether a given flare event is CME-eruptive or not is the ribbon area normalized by the sunspot area, which may indicate that the structural relationship between the flaring region and the entire AR controls CME productivity. AR characterization show that even X-class events do not require δ-sunspots or strong-field, high-gradient polarity inversion lines. An investigation of historical observational data suggests the possibility that the largest solar ARs, with magnetic flux of 2×10 23 Mx, might be able to produce "superflares" with energies of order of 10 34 erg. The proportionality between the flare durations and magnetic energies is consistent with stellar flare observations, suggesting a common physical background for solar and stellar flares.

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Magnetic Field Restructuring Associated With Two Successive Solar Eruptions

Cited by 34 publications

References 27 publications

Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability

Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability

The Physical Processes of CME/ICME Evolution

Magnetic Properties of Solar Active Regions That Govern Large Solar Flares and Eruptions

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