scholarly journals Solar Prominence Bubble and Plumes Caused By an Eruptive Magnetic Flux Rope

2021 ◽  
Vol 923 (1) ◽  
pp. L10
Author(s):  
Changxue Chen ◽  
Yang Su ◽  
Jianchao Xue ◽  
Weiqun Gan ◽  
Yu Huang
Keyword(s):  
Magnetic Flux ◽  
Extreme Ultraviolet ◽  
Flux Rope ◽  
Bubble Plume ◽  
Solar Prominence ◽  
Quiescent Prominence ◽  
Magnetic Flux Rope ◽  
Solar Prominences ◽  
Rayleigh Taylor Instability ◽  
Open Question

Abstract Prominence bubbles and plumes often form near the lower prominence–corona boundary. They are believed to play an important role in mass supply and evolution of solar prominences. However, how they form is still an open question. In this Letter we present a unique high-resolution Hα observation of a quiescent prominence by the New Vacuum Solar Telescope. Two noteworthy bubble–plume events are studied in detail. The two events are almost identical, except that an erupting mini filament appeared below the prominence–bubble interface in the second event, unlike the first one or any of the reported bubble observations. Analysis of the Hα and extreme-ultraviolet data indicates that the rising magnetic flux rope (MFR) in the mini filament is the cause of bubble expansion and that the interaction between the prominence and MFR results in plume formation. These observations provided clear evidence that emerging MFR may be a common trigger of bubbles and suggested a new mechanism of plumes in addition to Rayleigh–Taylor instability and reconnection.

scholarly journals Structure and Topology of Magnetic Fields in Solar Prominences

2013 ◽  
Vol 8 (S300) ◽  
pp. 127-134 ◽  
Author(s):  
Adriaan A. van Ballegooijen ◽  
Yingna Su
Keyword(s):  
Magnetic Flux ◽  
Flux Rope ◽  
Time Dependent ◽  
Magnetic Flux Rope ◽  
Magnetic Flux Ropes ◽  
And Topology ◽  
Solar Prominences ◽  
Magnetic Elements ◽  
Dependent Model ◽  
Time Dependent Model

AbstractRecent observations and models of solar prominences are reviewed. The observations suggest that prominences are located in or below magnetic flux ropes that lie horizontally above the PIL. However, the details of the magnetic structure are not yet fully understood. Gravity likely plays an important role in shaping the vertical structures observed in quiescent prominences. Preliminary results from a time-dependent model describing the interaction of a magnetic flux rope with photospheric magnetic elements are presented.

scholarly journals A new trigger mechanism for coronal mass ejections

2020 ◽  
Vol 644 ◽  
pp. A137
Author(s):  
A. W. James ◽  
L. M. Green ◽  
L. van Driel-Gesztelyi ◽  
G. Valori
Keyword(s):  
Magnetic Flux ◽  
Magnetic Reconnection ◽  
Extreme Ultraviolet ◽  
Flux Rope ◽  
Active Regions ◽  
Magnetic Activity ◽  
Trigger Mechanism ◽  
Magnetic Flux Rope ◽  
Left Handed ◽  
Flux Ropes

Context. Many previous studies have shown that the magnetic precursor of a coronal mass ejection (CME) takes the form of a magnetic flux rope, and a subset of them have become known as “hot flux ropes” due to their emission signatures in ∼10 MK plasma. Aims. We seek to identify the processes by which these hot flux ropes form, with a view of developing our understanding of CMEs and thereby improving space weather forecasts. Methods. Extreme-ultraviolet observations were used to identify five pre-eruptive hot flux ropes in the solar corona and study how they evolved. Confined flares were observed in the hours and days before each flux rope erupted, and these were used as indicators of episodic bursts of magnetic reconnection by which each flux rope formed. The evolution of the photospheric magnetic field was observed during each formation period to identify the process(es) that enabled magnetic reconnection to occur in the β <  1 corona and form the flux ropes. Results. The confined flares were found to be homologous events and suggest flux rope formation times that range from 18 hours to 5 days. Throughout these periods, fragments of photospheric magnetic flux were observed to orbit around each other in sunspots where the flux ropes had a footpoint. Active regions with right-handed (left-handed) twisted magnetic flux exhibited clockwise (anticlockwise) orbiting motions, and right-handed (left-handed) flux ropes formed. Conclusions. We infer that the orbital motions of photospheric magnetic flux fragments about each other bring magnetic flux tubes together in the corona, enabling component reconnection that forms a magnetic flux rope above a flaring arcade. This represents a novel trigger mechanism for solar eruptions and should be considered when predicting solar magnetic activity.

scholarly journals Three-dimensional MHD Simulations of Solar Prominence Oscillations in a Magnetic Flux Rope

2018 ◽  
Vol 856 (2) ◽  
pp. 179 ◽  
Author(s):  
Yu-Hao Zhou ◽  
C. Xia ◽  
R. Keppens ◽  
C. Fang ◽  
P. F. Chen
Keyword(s):  
Magnetic Flux ◽  
Three Dimensional ◽  
Flux Rope ◽  
Solar Prominence ◽  
Magnetic Flux Rope ◽  
Mhd Simulations

scholarly journals Buildup of a highly twisted magnetic flux rope during a solar eruption

2017 ◽  
Vol 8 (1) ◽  
Author(s):  
Wensi Wang ◽  
Rui Liu ◽  
Yuming Wang ◽  
Qiang Hu ◽  
Chenglong Shen ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Flux Rope ◽  
Magnetic Flux Rope

scholarly journals Magnetic flux rope formation within a magnetosheath hot flow anomaly

2012 ◽  
Vol 117 (A9) ◽  
pp. n/a-n/a ◽  
Author(s):  
H. Hasegawa ◽  
H. Zhang ◽  
Y. Lin ◽  
B. U. Ö. Sonnerup ◽  
S. J. Schwartz ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Flux Rope ◽  
Magnetic Flux Rope

VERTICAL KINK OSCILLATION OF A MAGNETIC FLUX ROPE STRUCTURE IN THE SOLAR CORONA

2014 ◽  
Vol 797 (2) ◽  
pp. L22 ◽  
Author(s):  
S. Kim ◽  
V. M. Nakariakov ◽  
K.-S. Cho
Keyword(s):  
Magnetic Flux ◽  
Solar Corona ◽  
Flux Rope ◽  
Magnetic Flux Rope

MAVEN Survey of Magnetic Flux Rope Properties in the Martian Ionosphere: Comparison with 3 Types of Formation Mechanisms

2021 ◽  
Author(s):  
Charles Bowers ◽  
James A. Slavin ◽  
Gina A. DiBraccio ◽  
Gangkai Poh ◽  
Takuya Hara ◽  
...  
Keyword(s):  
Magnetic Flux ◽  
Flux Rope ◽  
Formation Mechanisms ◽  
Magnetic Flux Rope ◽  
Martian Ionosphere

scholarly journals Hydrogen non-equilibrium ionisation effects in coronal mass ejections

2020 ◽  
Vol 637 ◽  
pp. A49
Author(s):  
P. Pagano ◽  
A. Bemporad ◽  
D. H. Mackay
Keyword(s):  
Magnetic Flux ◽  
Visible Light ◽  
Coronal Mass Ejections ◽  
Flux Rope ◽  
Neutral Hydrogen ◽  
Hydrogen Atoms ◽  
Mhd Simulation ◽  
Magnetic Flux Rope ◽  
New Generation ◽  
Non Equilibrium

Context. A new generation of coronagraphs used to study solar wind and coronal mass ejections (CMEs) are being developed and launched. These coronagraphs will heavily rely on multi-channel observations where visible light (VL) and UV-EUV (ultraviolet-extreme ultraviolet) observations provide new plasma diagnostics. One of these instruments, Metis on board ESA-Solar Orbiter, will simultaneously observe VL and the UV Lyman-α line. The number of neutral hydrogen atoms (a small fraction of coronal protons) is a key parameter for deriving plasma properties, such as the temperature from the observed Lyman-α line intensity. However, these measurements are significantly affected if non-equilibrium ionisation effects occur, which can be relevant during CMEs. Aims. The aim of this work is to determine if non-equilibrium ionisation effects are relevant in CMEs and, in particular, when and in which regions of the CME plasma ionisation equilibrium can be assumed for data analysis. Methods. We used a magneto-hydrodynamic (MHD) simulation of a magnetic flux rope ejection to generate a CME. From this, we then reconstructed the ionisation state of hydrogen atoms in the CME by evaluating both the advection of neutral and ionised hydrogen atoms and the ionisation and recombination rates in the MHD simulation. Results. We find that the equilibrium ionisation assumption mostly holds in the core of the CME, which is represented by a magnetic flux rope. In contrast, non-equilibrium ionisation effects are significant at the CME front, where we find about 100 times more neutral hydrogen atoms than prescribed by ionisation equilibrium conditions. We find this to be the case even if this neutral hydrogen excess might be difficult to identify due to projection effects. Conclusions. This work provides key information for the development of a new generation of diagnostic techniques that aim to combine visible light and Lyman-α line emissions. The results show that non-equilibrium ionisation effects need to be considered when we analyse CME fronts. Incorrectly assuming equilibrium ionisation in these regions would lead to a systematic underestimate of plasma temperatures.

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