Magnetohydrodynamic Waves in Multi-Layered Asymmetric Waveguides: Solar Magneto-Seismology Theory and Application
Diagnosing the solar atmospheric plasma is one of the major challenges in solar physics. Magnetohydrodynamic (MHD) waves, by means of applying the powerful concept of solar magneto-seismology (SMS), provide a tool to obtain diagnostic insight into the magnetized solar plasma in MHD waveguides. This...
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| Format: | Article |
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Frontiers Media S.A.
2019-07-01
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| Series: | Frontiers in Astronomy and Space Sciences |
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| Online Access: | https://www.frontiersin.org/article/10.3389/fspas.2019.00048/full |
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| author | Matthew Allcock Daria Shukhobodskaia Noémi Kinga Zsámberger Noémi Kinga Zsámberger Noémi Kinga Zsámberger Robert Erdélyi Robert Erdélyi |
| author_facet | Matthew Allcock Daria Shukhobodskaia Noémi Kinga Zsámberger Noémi Kinga Zsámberger Noémi Kinga Zsámberger Robert Erdélyi Robert Erdélyi |
| author_sort | Matthew Allcock |
| collection | DOAJ |
| description | Diagnosing the solar atmospheric plasma is one of the major challenges in solar physics. Magnetohydrodynamic (MHD) waves, by means of applying the powerful concept of solar magneto-seismology (SMS), provide a tool to obtain diagnostic insight into the magnetized solar plasma in MHD waveguides. This paper provides a road-map of simple but applicable models of solar atmospheric waveguides in the framework of Cartesian geometry. We focus on exploiting the diagnostic potential of waveguide asymmetry and consider the effects of steady flow. In particular, the dispersion relation describing linear MHD wave propagation along a multi-layered MHD waveguide is derived. Aiming at lower solar atmospheric applications of SMS, the special case of a single magnetic slab embedded in an asymmetric magnetized plasma environment is revisited. As a proof of concept, the Amplitude Ratio Method is used to make a seismological estimate of the local Alfvén speed in several chromospheric fibrils that exhibit asymmetric oscillations. Absolute ratios of boundary oscillations between 1.29 and 3.42 are detected and, despite the significant errors expected, the local Alfvén speed estimates agree with previously derived estimates from magnetic field extrapolations. Finally, the effects of asymmetric shear flows present in these slab MHD waveguides are considered as a suitable model of Kelvin-Helmholtz instability initiation that is applicable, for example, to coronal mass ejection flanks. |
| first_indexed | 2024-12-13T02:32:35Z |
| format | Article |
| id | doaj.art-59cf683758e04a9c838cb645773fc93f |
| institution | Directory Open Access Journal |
| issn | 2296-987X |
| language | English |
| last_indexed | 2024-12-13T02:32:35Z |
| publishDate | 2019-07-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Astronomy and Space Sciences |
| spelling | doaj.art-59cf683758e04a9c838cb645773fc93f2022-12-22T00:02:28ZengFrontiers Media S.A.Frontiers in Astronomy and Space Sciences2296-987X2019-07-01610.3389/fspas.2019.00048456255Magnetohydrodynamic Waves in Multi-Layered Asymmetric Waveguides: Solar Magneto-Seismology Theory and ApplicationMatthew Allcock0Daria Shukhobodskaia1Noémi Kinga Zsámberger2Noémi Kinga Zsámberger3Noémi Kinga Zsámberger4Robert Erdélyi5Robert Erdélyi6Solar Physics and Space Plasma Research Centre, School of Mathematics and Statistics, University of Sheffield, Sheffield, United KingdomSolar Physics and Space Plasma Research Centre, School of Mathematics and Statistics, University of Sheffield, Sheffield, United KingdomSolar Physics and Space Plasma Research Centre, School of Mathematics and Statistics, University of Sheffield, Sheffield, United KingdomInstitute of Physics, University of Debrecen, Debrecen, HungaryDoctoral School of Physics, University of Debrecen, Debrecen, HungarySolar Physics and Space Plasma Research Centre, School of Mathematics and Statistics, University of Sheffield, Sheffield, United KingdomDepartment of Astronomy, Eötvös L. University, Budapest, HungaryDiagnosing the solar atmospheric plasma is one of the major challenges in solar physics. Magnetohydrodynamic (MHD) waves, by means of applying the powerful concept of solar magneto-seismology (SMS), provide a tool to obtain diagnostic insight into the magnetized solar plasma in MHD waveguides. This paper provides a road-map of simple but applicable models of solar atmospheric waveguides in the framework of Cartesian geometry. We focus on exploiting the diagnostic potential of waveguide asymmetry and consider the effects of steady flow. In particular, the dispersion relation describing linear MHD wave propagation along a multi-layered MHD waveguide is derived. Aiming at lower solar atmospheric applications of SMS, the special case of a single magnetic slab embedded in an asymmetric magnetized plasma environment is revisited. As a proof of concept, the Amplitude Ratio Method is used to make a seismological estimate of the local Alfvén speed in several chromospheric fibrils that exhibit asymmetric oscillations. Absolute ratios of boundary oscillations between 1.29 and 3.42 are detected and, despite the significant errors expected, the local Alfvén speed estimates agree with previously derived estimates from magnetic field extrapolations. Finally, the effects of asymmetric shear flows present in these slab MHD waveguides are considered as a suitable model of Kelvin-Helmholtz instability initiation that is applicable, for example, to coronal mass ejection flanks.https://www.frontiersin.org/article/10.3389/fspas.2019.00048/fullsolar atmosphereplasmawavesmagnetohydrodynamics (MHD)magnetic fieldsmagneto-seismology |
| spellingShingle | Matthew Allcock Daria Shukhobodskaia Noémi Kinga Zsámberger Noémi Kinga Zsámberger Noémi Kinga Zsámberger Robert Erdélyi Robert Erdélyi Magnetohydrodynamic Waves in Multi-Layered Asymmetric Waveguides: Solar Magneto-Seismology Theory and Application Frontiers in Astronomy and Space Sciences solar atmosphere plasma waves magnetohydrodynamics (MHD) magnetic fields magneto-seismology |
| title | Magnetohydrodynamic Waves in Multi-Layered Asymmetric Waveguides: Solar Magneto-Seismology Theory and Application |
| title_full | Magnetohydrodynamic Waves in Multi-Layered Asymmetric Waveguides: Solar Magneto-Seismology Theory and Application |
| title_fullStr | Magnetohydrodynamic Waves in Multi-Layered Asymmetric Waveguides: Solar Magneto-Seismology Theory and Application |
| title_full_unstemmed | Magnetohydrodynamic Waves in Multi-Layered Asymmetric Waveguides: Solar Magneto-Seismology Theory and Application |
| title_short | Magnetohydrodynamic Waves in Multi-Layered Asymmetric Waveguides: Solar Magneto-Seismology Theory and Application |
| title_sort | magnetohydrodynamic waves in multi layered asymmetric waveguides solar magneto seismology theory and application |
| topic | solar atmosphere plasma waves magnetohydrodynamics (MHD) magnetic fields magneto-seismology |
| url | https://www.frontiersin.org/article/10.3389/fspas.2019.00048/full |
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