scholarly journals The exceptional aspects of the confined X-class flares of solar active region 2192

2015 ◽  
Vol 11 (S320) ◽  
pp. 60-63
Author(s):  
Julia K. Thalmann ◽  
Yang Su ◽  
Manuela Temmer ◽  
Astrid M. Veronig
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Active Region Noaa ◽  
High Energies ◽  
The Past ◽  
Large Scale Magnetic Field ◽  
High Level ◽  
Mass Ejection

AbstractDuring late October 2014, active region NOAA 2192 caused an unusual high level of solar activity, within an otherwise weak solar cycle. While crossing the solar disk, during a period of 11 days, it was the source of 114 flares of GOES class C1.0 and larger, including 29 M- and 6 X-flares. Surprisingly, none of the major flares (GOES class M5.0 and larger) was accompanied by a coronal mass ejection, contrary to statistical tendencies found in the past. From modeling the coronal magnetic field of NOAA 2192 and its surrounding, we suspect that the cause of the confined character of the flares is the strong surrounding and overlying large-scale magnetic field. Furthermore, we find evidence for multiple magnetic reconnection processes within a single flare, during which electrons were accelerated to unusual high energies.

Effects of optimisation parameters on data-driven magnetofrictional modelling 

2021 ◽  
Author(s):  
Anshu Kumari ◽  
Daniel Price ◽  
Emilia Kilpua ◽  
Jens Pomoell ◽  
Farhad Daei
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Large Scale ◽  
Magnetic Energy ◽  
Flux Rope ◽  
Coronal Magnetic Field ◽  
Early Evolution ◽  
Data Driven ◽  
Magnetic Field Magnitude ◽  
Mass Ejection

<p>The solar coronal magnetic field plays an important role in the formation, evolution, and dynamics of small and large-scale structures in the corona. Estimation of the coronal magnetic field, the ultimate driver of space weather, particularly in the ‘low’ and ‘middle’ corona, is presently limited due to practical difficulties. Data-driven time-dependent magnetofrictional modelling (TMFM) of active region magnetic fields has been proven as a tool to observe and study the corona. In this work, we present a detailed study of data-driven TMFM of active region 12473 to trace the early evolution of the flux rope related to the coronal mass ejection that occurred on 28 December 2015. Non-inductive electric field component in the photosphere is critical for energizing and introducing twist to the coronal magnetic field, thereby allowing unstable configurations to be formed. We estimate this component using an approach based on optimizing the injection of magnetic energy. We study the effects of these optimisation parameters on the data driven coronal simulations. By varying the free optimisation parameters, we explore the changes in flux rope formation and their early evolution, as well other parameters, e.g. axial flux, magnetic field magnitude.</p>

scholarly journals Shearing motions and torus instability in the 2010 April 3 filament eruption

2013 ◽  
Vol 8 (S300) ◽  
pp. 475-476
Author(s):  
F. P. Zuccarello ◽  
P. Romano ◽  
F. Zuccarello ◽  
S. Poedts
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Flux Rope ◽  
Active Region Noaa ◽  
Axial Field ◽  
Drift Motion ◽  
Filament Eruption ◽  
Onset Condition ◽  
Mass Ejection ◽  
The Magnetic Field

AbstractThe magnetic field evolution of active region NOAA 11059 is studied in order to determine the possible causes and mechanisms that led to the initiation of the 2010 April 3 coronal mass ejection (CME).We find (1) that the magnetic configuration of the active region is unstable to the torus instability and (2) that persistent shearing motions characterized the negative polarity, resulting in a southward, almost parallel to the meridians, drift motion of the negative magnetic field concentrations.We conclude that these shearing motions increased the axial field of the filament eventually bringing the flux rope axis to a height where the onset condition for the torus instability was satisfied.

scholarly journals Reconstruction of the Coronal Magnetic Field for Active Region NOAA 8151

2001 ◽  
Vol 203 ◽  
pp. 441-443
Author(s):  
S. Régnier ◽  
T. Amari
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Magnetic Energy ◽  
Coronal Magnetic Field ◽  
X Rays ◽  
Active Region Noaa ◽  
Filament Eruption ◽  
Linear Force ◽  
Region Noaa ◽  
Field Lines

The active region NOAA 8151 observed between February 11–13, 1998 exhibits a filament eruption linked to the disappearance of a sigmoidal structure. Using vector magnetograms from IVM (Mees Observatory, Hawaii), we perform a non linear force-free reconstruction of the coronal magnetic field above this active region. This reconstruction allows to determine the distribution of electric currents, the magnetic energy and the relative magnetic helicity. The reconstructed magnetic field lines are compared to the soft X-rays (SXT, Yohkoh) observations.

scholarly journals THE ROLE OF ACTIVE REGION CORONAL MAGNETIC FIELD IN DETERMINING CORONAL MASS EJECTION PROPAGATION DIRECTION

2015 ◽  
Vol 814 (1) ◽  
pp. 80 ◽  
Author(s):  
Rui Wang ◽  
Ying D. Liu ◽  
Xinghua Dai ◽  
Zhongwei Yang ◽  
Chong Huang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Active Region ◽  
Coronal Mass Ejection ◽  
Coronal Magnetic Field ◽  
Propagation Direction ◽  
Mass Ejection

Large-Scale Coronal Magnetic Field and Density Structures

1994 ◽  
Vol 144 ◽  
pp. 155-157
Author(s):  
S. Gibson ◽  
F. Bagenal
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Large Scale ◽  
Solar Maximum ◽  
Coronal Magnetic Field ◽  
Field Observations ◽  
Solar Maximum Mission ◽  
Solar Wind Acceleration ◽  
Large Scale Magnetic Field ◽  
The Magnetic Field

AbstractWe have modelled the large-scale magnetic field and density structures in the corona using the magnetostatic model of Bogdan and Low (1986) and white light images from both NASA’s Solar Maximum Mission (SMM) Coronagraph/Polarimeter and the High Altitude Observatory Mark III (MkIII) K-coronameter (Bagenal and Gibson, 1991; Gibson and Bagenal, 1992.)We have used the magnetostatic model to calculate the magnetic field, density, pressure, and temperature distribution in the corona. Moreover, we have studied how, if at all, photospheric magnetic field observations could be used to improve predictions of coronal fields.We are at present examining the implications of our predictions of magnetic field and density structures have for coronal heating and solar wind acceleration. We are also analysing the robustness of these predictions, studying both observational and model related errors.

scholarly journals Role of the background regimes towards the Solar Mean Magnetic Field (SMMF)

2018 ◽  
Vol 13 (S340) ◽  
pp. 85-86
Author(s):  
Souvik Bose ◽  
K. Nagaraju
Keyword(s):  
Magnetic Field ◽  
Large Scale ◽  
Active Regions ◽  
Line Of Sight ◽  
The Sun ◽  
The Past ◽  
Large Scale Magnetic Field

AbstractThe Solar Mean Magnetic Field (SMMF) is generally defined as the disc-averaged line-of-sight (LOS) magnetic field on the sun. The role of the active regions and the large-scale magnetic field structures (also called the background) has been debated over the past few decades to understand whether the origin of the SMMF is either due to the active regions or the background. We, in this paper have investigated contribution of sunspots, plages, networks and the background towards the variability of the SMMF using the datasets from the SDO-AIA & HMI, and found that 89% of the SMMF is due to the background whereas the remaining 11% originates from the active regions and the networks.

scholarly journals A three-dimensional velocity of an erupting prominence prior to a coronal mass ejection

2021 ◽  
Vol 73 (2) ◽  
pp. 394-404
Author(s):  
Maria V Gutierrez ◽  
Kenichi Otsuji ◽  
Ayumi Asai ◽  
Raul Terrazas ◽  
Mutsumi Ishitsuka ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Extreme Ultraviolet ◽  
Three Dimensional ◽  
Coronal Magnetic Field ◽  
Coronal Loops ◽  
Active Region Noaa ◽  
Loop Expansion ◽  
Mass Ejection ◽  
Multiple Interactions ◽  
Full Disk

Abstract We present a detailed three-dimensional (3D) view of a prominence eruption, coronal loop expansion, and coronal mass ejections (CMEs) associated with an M4.4 flare that occurred on 2011 March 8 in the active region NOAA 11165. Full-disk Hα images of the flare and filament ejection were successfully obtained by the Flare Monitoring Telescope (FMT) following its relocation to Ica University, Peru. Multiwavelength observation around the Hα line enabled us to derive the 3D velocity field of the Hα prominence eruption. Features in extreme ultraviolet were also obtained by the Atmospheric Imager Assembly onboard the Solar Dynamic Observatory and the Extreme Ultraviolet Imager on board the Solar Terrestrial Relations Observatory - Ahead satellite. We found that, following collision of the erupted filament with the coronal magnetic field, some coronal loops began to expand, leading to the growth of a clear CME. We also discuss the succeeding activities of CME driven by multiple interactions between the expanding loops and the surrounding coronal magnetic field.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Sign in / Sign up

Export Citation Format

Share Document