Parallel Evolution of Quasi-Separatrix Layers and Active Region Upflows

Mandrini, C. H.; Baker, D.; Démoulin, P.; Cristiani, G.; Driel‐Gesztelyi, L. van; Domínguez, S. Vargas; Nuevo, F. A.; Vásquez, A. M.; Pick, M.

doi:10.1088/0004-637x/809/1/73

Cited by 35 publications

(39 citation statements)

References 64 publications

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“…Our model includes also a transformation of coordinates from the local AR frame to the observed one (see Démoulin et al 1997), so that the computed field lines can be directly compared to the observed loops. For more details about how the computational box is selected and its size controlled, see Mandrini et al (2015). Typical coronal conditions imply that the magnetic field is force free and frozen into the plasma almost everywhere in solar ARs.…”

Section: The Local Magnetic-field Modelmentioning

confidence: 99%

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Blowout jets and impulsive eruptive flares in a bald-patch topology

Chandra

Mandrini

Schmieder

et al. 2017

A&A

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Context. A subclass of broad EUV and X-ray jets, called blowout jets, have become a topic of research since they could be the link between standard collimated jets and CMEs. Aims. Our aim is to understand the origin of a series of broad jets, some accompanied by flares and associated with narrow and jet-like CMEs. Methods. We analyze observations of a series of recurrent broad jets observed in AR 10484 on 21 -24 October 2003. In particular, one of them occurred simultaneously with an M2.4 flare on 23 October at 02:41 UT (SOLA2003-10-23). Both events were observed by ARIES Hα Solar Tower-Telescope, TRACE, SOHO, and RHESSI instruments. The flare was very impulsive and followed by a narrow CME. A local force-free model of AR 10484 is the basis to compute its topology. We find bald patches (BPs) at the flare site. This BP topology is present for at least two days before. Large-scale field lines, associated with the BPs, represent open loops. This is confirmed by a global PFSS model. Following the brightest leading edge of the Hα and EUV jet emission, we can temporarily associate it with a narrow CME. Results. Considering their characteristics, the observed broad jets appear to be of the blowout class. As the most plausible scenario, we propose that magnetic reconnection could occur at the BP separatrices forced by the destabilization of a continuously reformed flux rope underlying them. The reconnection process could bring the cool flux-rope material into the reconnected open field lines driving the series of recurrent blowout jets and accompanying CMEs. Conclusions. Based on a model of the coronal field, we compute the AR 10484 topology at the location where flaring and blowout jets occurred from 21 to 24 October 2003. This topology can consistently explain the origin of these events.

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Section: The Local Magnetic-field Modelmentioning

confidence: 99%

“…We infer the direction in which reconnection proceeds from the observed event evolution (see e.g. Mandrini et al 2015, and references therein). In Fig.…”

Section: Bps In Ar 10484mentioning

confidence: 99%

Blowout jets and impulsive eruptive flares in a bald-patch topology

Chandra

Mandrini

Schmieder

et al. 2017

A&A

Self Cite

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“…It is commonly believed that it is due to that the emission optical depth increases with the emission frequency to the square (Benz 1993). On the other hand, the range of type-I chains (below ∼400 MHz) shows that these chains are generated at upper parts of the active-region loops located close to the quasi-separatrix layers of the active region as proposed by Mandrini et al (2015).…”

Section: New Model Of Type-i Chainsmentioning

confidence: 80%

“…However, type-I chains are observed in metric range and DPSs in decimetric range, that is, in different altitudes of the solar atmosphere with different densities, different density gradients and magnetic field strengths. Moreover, while DPSs are usually observed during the impulsive phase of eruptive flares (Nishizuka et al 2015), type-I chains are a part of noise storms connected with the reconnection activity at the quasi-separatrix layer in the active region (Mandrini et al 2015).…”

Section: Comparison Of Chains Of Type-i Radio Bursts and Drifting Pulmentioning

confidence: 99%

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Chains of type-I radio bursts and drifting pulsation structures

Karlický

2017

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Aims. Owing to similarities of chains of type-I radio bursts and drifting pulsation structures the question arises as to whether both these radio bursts are generated by similar processes. Methods. Characteristics and parameters of both these radio bursts are compared. Results. We present examples of both types of bursts and show their similarities and differences. Then, for chains of type-I bursts, a similar model as for drifting pulsation structures (DPSs) is proposed. We show that, similar to the DPS model, the chains of type-I bursts can be generated by the fragmented magnetic reconnection associated with plasmoid interactions. To support this new model of chains of type-I bursts, we present an effect of merging two plasmoids to form one larger plasmoid on the radio spectrum of DPS. This process can also explain the 'wavy' appearance of some chains of type-I bursts. Further, we show that the chains of type-I bursts with the wavy appearance can be used for estimation of the magnetic field strength in their sources. We think that differences of chains of type-I bursts and DPSs are mainly owing to different regimes of the magnetic field reconnection. While in the case of chains of type-I bursts, the magnetic reconnection and plasmoid interactions are in the quasi-separatrix layer of the active region in more or less quasi-saturated regime, in the case of DPSs, observed in the impulsive phase of eruptive flares, the magnetic reconnection and plasmoid interactions are in the current sheet formed under the flare magnetic rope, which moves upwards and forces this magnetic reconnection.

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Apparent and Intrinsic Evolution of Active Region Upflows

et al. 2017

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We analyze the evolution of Fe XII coronal plasma upflows from the edges of ten active regions (ARs) as they cross the solar disk using the Hinode Extreme Ultraviolet Imaging Spectrometer (EIS) to do this. Confirming the results of Démoulin et al. (Sol. Phys. 283, 341, 2013), we find that for each AR there is an observed long-term evolution of the upflows. This evolution is largely due to the solar rotation that progressively changes the viewpoint of dominantly stationary upflows. From this projection effect, we estimate the unprojected upflow velocity and its inclination to the local vertical. AR upflows typically fan away from the AR core by 40°to nearly vertical for the following polarity. The span of inclination angles is more spread out for the leading polarity, with flows angled from −29°(inclined toward the AR center) to 28°(directed away from the AR). In addition to the limb-to-limb apparent evolution, we identify an intrinsic evolution of the upflows that is due to coronal activity, which is AR dependent. Furthermore, line widths are correlated with Electronic supplementary material The online version of this article

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Parallel Evolution of Quasi-Separatrix Layers and Active Region Upflows

Cited by 35 publications

References 64 publications

Blowout jets and impulsive eruptive flares in a bald-patch topology

Blowout jets and impulsive eruptive flares in a bald-patch topology

Chains of type-I radio bursts and drifting pulsation structures

Apparent and Intrinsic Evolution of Active Region Upflows

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