Publication detail

Global Non-Potential Magnetic Models of the Solar Corona During the March 2015 Eclipse

YEATES, A. AMARI, T. CONTOPOULOS, I. XUESHANG, F. MACKAY, D. MIKIČ, Z. WIEGELMANN, T. HUTTON, J. LOWDER, C. MORGAN, H. PETRIE, G. RACHMELER, L. UPTON, L. CANOU, A. CHOPIN, P. COOPER, D. DRUCKMÜLLER, M. LINKER, J. SEATON, D. TOROK, T.

Original Title

Global Non-Potential Magnetic Models of the Solar Corona During the March 2015 Eclipse

English Title

Global Non-Potential Magnetic Models of the Solar Corona During the March 2015 Eclipse

Type

journal article in Web of Science

Language

en

Original Abstract

Seven different models are applied to the same problem of simulating the Sun's coronal magnetic field during the solar eclipse on 2015 March 20. All of the models are non-potential, allowing for free magnetic energy, but the associated electric currents are developed in significantly different ways. This is not a direct comparison of the coronal modelling techniques, in that the different models also use different photospheric boundary conditions, reflecting the range of approaches currently used in the community. Despite the significant differences, the results show broad agreement in the overall magnetic topology. Among those models with significant volume currents in much of the corona, there is general agreement that the ratio of total to potential magnetic energy should be approximately 1.4. However, there are significant differences in the electric current distributions; while static extrapolations are best able to reproduce active regions, they are unable to recover sheared magnetic fields in filament channels using currently available vector magnetogram data. By contrast, time-evolving simulations can recover the filament channel fields at the expense of not matching the observed vector magnetic fields within active regions. We suggest that, at present, the best approach may be a hybrid model using static extrapolations but with additional energization informed by simplified evolution models. This is demonstrated by one of the models.

English abstract

Seven different models are applied to the same problem of simulating the Sun's coronal magnetic field during the solar eclipse on 2015 March 20. All of the models are non-potential, allowing for free magnetic energy, but the associated electric currents are developed in significantly different ways. This is not a direct comparison of the coronal modelling techniques, in that the different models also use different photospheric boundary conditions, reflecting the range of approaches currently used in the community. Despite the significant differences, the results show broad agreement in the overall magnetic topology. Among those models with significant volume currents in much of the corona, there is general agreement that the ratio of total to potential magnetic energy should be approximately 1.4. However, there are significant differences in the electric current distributions; while static extrapolations are best able to reproduce active regions, they are unable to recover sheared magnetic fields in filament channels using currently available vector magnetogram data. By contrast, time-evolving simulations can recover the filament channel fields at the expense of not matching the observed vector magnetic fields within active regions. We suggest that, at present, the best approach may be a hybrid model using static extrapolations but with additional energization informed by simplified evolution models. This is demonstrated by one of the models.

Keywords

Magnetic fields, Sun, surface magnetism; corona

Released

08.08.2018

Publisher

Springer Netherlands

Location

Holandsko

Pages from

99

Pages to

126

Pages count

27

URL

Documents

BibTex


@article{BUT149270,
  author="Anthony R. {Yeates} and Tahar {Amari} and Ioannis {Contopoulos} and Feng {Xueshang} and Duncan H. {Mackay} and Zoran {Mikič} and Thomas {Wiegelmann} and Joseph {Hutton} and Christopher A. {Lowder} and Huw {Morgan} and Gordon {Petrie} and Laurel A. {Rachmeler} and Lisa A. {Upton} and Aurelien {Canou} and Pierre {Chopin} and Downs {Cooper} and Miloslav {Druckmüller} and J.A. {Linker} and Daniel B. {Seaton} and Tibor {Torok}",
  title="Global Non-Potential Magnetic Models of the Solar Corona During the March 2015 Eclipse",
  annote="Seven different models are applied to the same problem of simulating the Sun's coronal magnetic field during the solar eclipse on 2015 March 20. All of the models are non-potential, allowing for free magnetic energy, but the associated electric currents are developed in significantly different ways. This is not a direct comparison of the coronal modelling techniques, in that the different models also use different photospheric boundary conditions, reflecting the range of approaches currently used in the community. Despite the significant differences, the results show broad agreement in the overall magnetic topology. Among those models with significant volume currents in much of the corona, there is general agreement that the ratio of total to potential magnetic energy should be approximately 1.4. However, there are significant differences in the electric current distributions; while static extrapolations are best able to reproduce active regions, they are unable to recover sheared magnetic fields in filament channels using currently available vector magnetogram data. By contrast, time-evolving simulations can recover the filament channel fields at the expense of not matching the observed vector magnetic fields within active regions. We suggest that, at present, the best approach may be a hybrid model using static extrapolations but with additional energization informed by simplified evolution models. This is demonstrated by one of the models.",
  address="Springer Netherlands",
  chapter="149270",
  doi="10.1007/s11214-018-0534-1",
  howpublished="print",
  institution="Springer Netherlands",
  number="5",
  volume="214",
  year="2018",
  month="august",
  pages="99--126",
  publisher="Springer Netherlands",
  type="journal article in Web of Science"
}