Gradual Magnetic Evolution of Sunspot Structure and Filament–corona Dynamics Associated With the X1.8 Flare in Ar11283

Ruan, Guiping; Chen, Yao; Wang, Haimin

doi:10.1088/0004-637x/812/2/120

Cited by 13 publications

(12 citation statements)

References 31 publications

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“…partly absent penumbrae (see, e.g., Figure 2 in Ruan et al 2015). As for the X1.5 flare in AR 11166, one can argue that oppositely directed shear-induced current systems form between the three flux clusters.…”

Section: Data Analysis and Reviewmentioning

confidence: 91%

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The Nonpotentiality of Coronae of Solar Active Regions, the Dynamics of the Surface Magnetic Field, and the Potential for Large Flares

Schrijver

2016

ApJ

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Flares and eruptions from solar active regions (ARs) are associated with atmospheric electrical currents accompanying distortions of the coronal field away from a lowest-energy potential state. In order to better understand the origin of these currents and their role in M-and X-class flares, I review all AR observations made with Solar Dynamics Observatory (SDO)/Helioseismic and Magnetic Imager and SDO/Atmospheric Imaging Assembly from 2010 May through 2014 October within ≈40°from the disk center. I select the roughly 4% of all regions that display a distinctly nonpotential coronal configuration in loops with a length comparable to the scale of the AR, and all that emit GOES X-class flares. The data for 41 regions confirm, with a single exception, that strong-field, high-gradient polarity inversion lines (SHILs) created during emergence of magnetic flux into, and related displacement within, pre-existing ARs are associated with X-class flares. Obvious nonpotentiality in the AR-scale loops occurs in six of ten selected regions with X-class flares, all with relatively long SHILs along their primary polarity inversion line, or with a long internal filament there. Nonpotentiality can exist in ARs well past the flux-emergence phase, often with reduced or absent flaring. I conclude that the dynamics of the flux involved in the compact SHILs is of pre-eminent importance for the large-flare potential of ARs within the next day, but that their associated currents may not reveal themselves in AR-scale nonpotentiality. In contrast, AR-scale nonpotentiality, which can persist for many days, may inform us about the eruption potential other than those from SHILs which is almost never associated with X-class flaring.

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Section: Data Analysis and Reviewmentioning

confidence: 91%

“…The X1.8 flare on 2011 September 7 is notable because of a substantial amount of chromospheric material being ejected. The field evolution around the time of the two X-class flares was described by Ruan et al (2014Ruan et al ( , 2015. These studies note that both major flares were associated with clear sunspot rotation.…”

Section: Ar 11283mentioning

confidence: 93%

The Nonpotentiality of Coronae of Solar Active Regions, the Dynamics of the Surface Magnetic Field, and the Potential for Large Flares

Schrijver

2016

ApJ

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“…The helicity decreases rapidly during each of the last three eruptions due to a mass of magnetic flux ejected into the higher corona. It begins to decrease prior to the major flare of E3 (the decrease is associated with a C-class flare eruption; Ruan et al 2015), undergoing a mild release, and even continues to decrease for a period after E3.…”

Section: Eruptionsmentioning

confidence: 99%

“…There have already been several studies on AR 11283 (e.g., Feng et al 2013;Jiang et al 2014;Ruan et al 2014;Liu et al 2014a;Romano et al 2015;Ruan et al 2015;Zhang et al 2015;Jiang et al 2016;Dissauer et al 2016;Sarkar et al 2019). Compared to these previous work about this AR, we are interested in how the new magnetic free energy and helicity build up from the remnant of the magnetic fields left by the previous eruption, and how the MFRs build up with the energy and helicity injected.…”

mentioning

confidence: 98%

Buildup of the Magnetic Flux Ropes in Homologous Solar Eruptions

Wang,

Liu,

Yang

et al. 2022

Preprint

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Homologous coronal mass ejections (CMEs) are an interesting phenomenon, and it is possible to investigate the formation of CMEs by comparing multi-CMEs under a homologous physical condition. AR 11283 had been present on the solar surface for several days when a bipole emerged on 2011 September 4. Its positive polarity collided with the pre-existing negative polarity belonging to a different bipole, producing recurrent solar activities along the polarity inversion line (PIL) between the colliding polarities, namely the so-called collisional PIL (cPIL). Our results show that a large amount of energy and helicity were built up in the form of magnetic flux ropes (MFRs), with recurrent release and accumulation processes. These MFRs were built up along the cPIL. A flux deficit method is adopted and shows that magnetic cancellation happens along the cPIL due to the collisional shearing scenario proposed by Chintzoglou et al.The total amount of canceled flux was ∼0.7×10 21 Mx with an uncertainty of ∼13.2% within the confidence region of the 30 • sun-center distance. The canceled flux amounts to 24% of the total unsigned flux of the bipolar magnetic region. The results show that the magnetic fields beside the cPIL are very sheared, and the average shear angle is above 70 • after the collision. The fast expansion of the twist kernels of the MFRs and the continuous eruptive activities are both driven by the collisional shearing process. These results are important for better understanding the buildup process of the MFRs associated with homologous solar eruptions.

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“…Solar prominences are an important part of the solar corona, as they may often trigger solar eruptions and are generally a part of the coronal mass ejections (CMEs); see, e.g., Schmieder et al (2015), Ruan et al (2014Ruan et al ( , 2015, and Heinzel et al (2016). The prominence plasma temperature is relatively low compared with the temperature of its coronal environment by roughly two orders of magnitude (Labrosse et al 2010).…”

Section: Introductionmentioning

confidence: 99%

Diagnostics of the Prominence Plasma from Hα and Mg ii Spectral Observations

Ruan

Jejčič

Schmieder

et al. 2019

ApJ

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The goal of this paper is to derive the physical conditions of the prominence observed on 2017 March 30. To do so, we use a unique set of data in Mg II lines obtained with the space-borne Interface Region Imaging Spectrograph (IRIS) and in Hα line with the ground-based Multi-Channel Subtractive Double Pass spectrograph operating at the Meudon solar tower. Here, we analyze the prominence spectra of Mg II h and k lines, and the Hα line in the part of the prominence which is visible in both sets of lines. We compute a grid of 1D NLTE (i.e., departures from the local thermodynamical equilibrium) models providing synthetic spectra of Mg II k and h, and Hα lines in a large space of model input parameters (temperature, density, pressure, and microturbulent velocity). We compare Mg II and Hα line profiles observed in 75 positions of the prominence with the synthetic profiles from the grid of models. These models allow us to compute the relationships between the integrated intensities and between the optical thickness in Hα and Mg II k lines. The optical thickness τ Hα is between 0.05 and 2, and t Mg IIk is between 3 and 200. We show that the relationship of the observed integrated intensities agrees well with the synthetic integrated intensities for models with a higher microturbulence (16 km s −1 ) and T around 8000 K, ne=1.5×10 10 cm −3 , p=0.05 dyne. In this case, large microturbulence values could be a way to take into account the large mixed velocities existing in the observed prominence.

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Gradual Magnetic Evolution of Sunspot Structure and Filament–corona Dynamics Associated With the X1.8 Flare in Ar11283

Cited by 13 publications

References 31 publications

The Nonpotentiality of Coronae of Solar Active Regions, the Dynamics of the Surface Magnetic Field, and the Potential for Large Flares

The Nonpotentiality of Coronae of Solar Active Regions, the Dynamics of the Surface Magnetic Field, and the Potential for Large Flares

Buildup of the Magnetic Flux Ropes in Homologous Solar Eruptions

Diagnostics of the Prominence Plasma from Hα and Mg ii Spectral Observations

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