Rapid Penumbra and Lorentz Force Changes in an X1.0 Solar Flare

Xu, Zhe; Jiang, Yong; Yang, Jiayang; Yang, Bo; Bi, Yong

doi:10.3847/2041-8205/820/1/l21

Cited by 14 publications

(9 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mean horizontal magnetic field, calculated within the bounded box shown in Figure 12, decreased permanently by almost half of its initial value from about 600 Gauss to 300 Gauss (panel [e] of Figure 12) within less than half an hour during this eruptive flare. This scenario is consistent with the earlier finding of flare-related rapid penumbral decay away from the PIL and the associated permanent decrease in horizontal magnetic field (Xu et al, 2016). To further quantify this flare-related penumbral area decay, the time evolution of the penumbral area variation is illustrated in Figure 13.…”

Section: Morphological Evolution Of Ar 12192supporting

confidence: 76%

“…The rapid penumbral-area decay observed during the eruptive M4.0-class flare reveals how the strong Lorentz force impulse can shape the dynamics of the solar eruptions and cause morphological changes in the photospheric features. The physical explanation behind these flare-related photospheric morphological changes is given in Xu et al (2016). They showed that during the flare, due to the magnetic-pressure imbalance between the reconnection site and the outer atmosphere, the Lorentz force away from the PIL acts in the upward direction to lift up the magnetic field lines from the outer higher magnetic-pressure region towards the reconnection site.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

A Comparative Study of the Eruptive and Non-eruptive Flares Produced by the Largest Active Region of Solar Cycle 24

Sarkar

Srivastava

2018

Sol Phys

View full text Add to dashboard Cite

We investigate the morphological and magnetic characteristics of solar active region (AR) NOAA 12192. AR 12192 was the largest region of Solar Cycle 24; it underwent noticeable growth and produced 6 X-class flares, 22 M-class flares, and 53 C-class flares in the course of its disc passage. However, the most peculiar fact of this AR is that it was associated with only one CME in spite of producing several X-class flares. In this work, we carry out a comparative study between the eruptive and non-eruptive flares produced by AR 12192. We find that the magnitude of abrupt and permanent changes in the horizontal magnetic field and Lorentz force are significantly smaller in the case of the confined flares compared to the eruptive one. We present the areal evolution of AR 12192 during its disc passage. We find the flare-related morphological changes to be weaker during the confined flares, whereas the eruptive flare exhibits a rapid and permanent disappearance of penumbral area away from the magnetic neutral line after the flare. Furthermore, from the extrapolated nonlinear force-free magnetic field, we examine the overlying coronal magnetic environment over the eruptive and non-eruptive zones of the AR. We find that the critical decay index for the onset of torus instability was achieved at a lower height over the eruptive flaring region, than for the non-eruptive core area. These results suggest that the decay rate of the gradient of overlying magnetic field strength may play a decisive role to determine the CME productivity of the AR. In addition, the magnitude of changes in the flare-related magnetic characteristics are found to be well correlated with the nature of solar eruptions.

show abstract

Section: Morphological Evolution Of Ar 12192supporting

confidence: 76%

Section: Discussionmentioning

confidence: 99%

A Comparative Study of the Eruptive and Non-eruptive Flares Produced by the Largest Active Region of Solar Cycle 24

Sarkar

Srivastava

2018

Sol Phys

View full text Add to dashboard Cite

show abstract

“…Until to-date, many kinds of jet activities have been observed in different spectral lines, such as Hα surges (Roy 1973;Liu & Kurokawa 2004;Jiang et al 2007), extreme ultraviolet (EUV) (Shen et al 2012;Li et al 2015;Liu et al 2015;Shen et al 2011;Nisticò et al 2015;Kumar et al 2017;Zhu et al 2017;Tian et al 2017Tian et al , 2018 and X-ray jets (Shibata et al 1992;Vasheghani Farahani et al 2009;Moore et al 2010Moore et al , 2013Pucci et al 2013;Sterling et al 2015;Moore et al 2018). Many researches indicated that most solar jets result from magnetic reconnection in the low solar atmosphere (Shibata et al 1992(Shibata et al , 1994Canfield et al 1996;Shimojo et al 1996Shimojo et al , 1998Liu & Zhang 2002;Jiang et al 2007;Shen et al 2011;Hong et al 2011;Shen et al 2014;Li et al 2015;Liu et al 2015;Sterling et al 2015;Li et al 2015;Xu et al 2016;Hong et al 2017;Shen et al 2017Shen et al , 2012Adams et al 2014;Schmieder et al 2015;Yang et al 2016;…”

Section: Introductionmentioning

confidence: 99%

A New Small Satellite Sunspot Triggering Recurrent Standard and Blowout Coronal Jets

Miao

Liu

Shen

et al. 2019

ApJ

View full text Add to dashboard Cite

In this paper, we report a detailed analysis of recurrent jets originated from a location with emerging, canceling and converging negative magnetic field at the east edge of NOAA active region AR11166 from 2011 March 09 to 10. The event presented several interesting features. First, a satellite sunspot appeared and collided with a pre-existing opposite polarity magnetic field and caused a recurrent solar jet event. Second, the evolution of the jets showed blowout-like nature and standard characteristics. Third, the satellite sunspot exhibited a motion toward southeast of AR11166 and merged with the emerging flux near the opposite polarity sunspot penumbra, which afterward, due to flux convergence and cancellation episodes, caused recurrent jets. Fourth, three of the blowout jets associated with coronal mass ejections (CMEs), were observed from field of view of the Solar Terrestrial Relations Observatory. Fifth, almost all the blowout jet eruptions were accompanied with flares or with more intense brightening in the jet base region, while almost standard jets did not manifest such obvious feature during eruptions. The most important, the blowout jets were inclined to faster and larger scale than the standard jets. The standard jets instead were inclined to relative longer-lasting. The obvious shearing and twisting motions of the magnetic field may be interpreted as due to the shearing and twisting motions for a blowout jet eruption. From the statistical results, about 30% blowout jets directly developed into CMEs. It suggests that the blowout jets and CMEs should have a tight relationship.

show abstract

“…The penumbral structure and its carried flows are governed by the magnetic field strength and especially the field inclination, as revealed by previous observations (e.g., Ichimoto 2010;Deng et al 2011) and MHD simulations (Rempel et al 2009;Kitiashvili et al 2009). Thus, the expected more horizontal photospheric field configuration in response to the coronal restructuring as described above is strongly evidenced by observations of flare-related darkening and/or formation of penumbral structure, together with strengthened horizontal field and decreased inclination angle, near central flaring PILs Deng et al 2005;Chen et al 2007;Li et al 2009;Wang et al 2013;Xu et al 2016). It can be noted that these papers studied the structural evolution of penumbra mainly based on the overall intensity of penumbral segments, without examining in detail the associated penumbral flows.…”

Section: Introductionmentioning

confidence: 99%

Evolution of Photospheric Flow and Magnetic Fields Associated with the 2015 June 22 M6.5 Flare

Wang

Liu

Deng

et al. 2018

ApJ

View full text Add to dashboard Cite

The evolution of photospheric flow and magnetic fields before and after flares can provide important information regarding the flare triggering and back reaction processes. However, such studies on the flow field are rare due to the paucity of highresolution observations covering the entire flaring period. Here we study the structural evolution of penumbra and shear flows associated with the 2015 June 22 M6.5 flare in NOAA AR 12371, using high-resolution imaging observation in the TiO band taken by the 1.6 m Goode Solar Telescope at Big Bear Solar Observatory, with the aid of the differential affine velocity estimator method for flow tracking. The accompanied photospheric vector magnetic field changes are also analyzed using data from the Helioseismic and Magnetic Imager. As a result, we found, for a penumbral segment in the negative field adjacent to the magnetic polarity inversion line (PIL), an enhancement of penumbral flows (up to an unusually high value of ∼2 km s ) and extension of penumbral fibrils after the first peak of the flare hard X-ray (HXR) emission. We also found an area at the PIL, which is co-spatial with a precursor brightening kernel, exhibits a gradual increase of shear flow velocity (up to ∼0.9 km s −1 ) after the flare. The enhancing penumbral and shear flow regions are also accompanied by an increase of horizontal field and decrease of magnetic inclination angle(measured from the solar surface). These results are discussed in the context of the theory of back reaction of coronal restructuring on the photosphere as a result of flare energy release.

show abstract

Rapid Penumbra and Lorentz Force Changes in an X1.0 Solar Flare

Cited by 14 publications

References 42 publications

A Comparative Study of the Eruptive and Non-eruptive Flares Produced by the Largest Active Region of Solar Cycle 24

A Comparative Study of the Eruptive and Non-eruptive Flares Produced by the Largest Active Region of Solar Cycle 24

A New Small Satellite Sunspot Triggering Recurrent Standard and Blowout Coronal Jets

Evolution of Photospheric Flow and Magnetic Fields Associated with the 2015 June 22 M6.5 Flare

Contact Info

Product

Resources

About