Skip to content

Research at St Andrews

Forward modelling of MHD Waves in braided magnetic fields

Research output: Contribution to journalArticlepeer-review

Author(s)

School/Research organisations

Abstract

Aims. We investigate synthetic observational signatures generated from numerical models of transverse waves propagating in complex (braided) magnetic fields.
Methods. We consider two simulations with different levels of magnetic field braiding and impose periodic, transverse velocity perturbations at the lower boundary. As the waves reflect off the top boundary, a complex pattern of wave interference occurs.Weapply the forward modelling code FoMo and analyse the synthetic emission data. We examine line intensity, Doppler shifts and kinetic energy along several line-of-sight (LOS) angles.
Results. The Doppler shift perturbations clearly showed the presence of the transverse (Alfvénic) waves. However, in the total intensity (and running difference), the waves are less easily observed for more complex magnetic fields andmay be indistinguishablefrom background noise. Depending on the LOS angle, the observable signatures of the waves reflect some of the magnetic field braiding, particularly when multiple emission lines are available, although it is not possible to deduce the actual level ofcomplexity. In the more braided simulation, signatures of phase mixing can be identified. We highlight possible ambiguities in the interpretation of the wave modes based on the synthetic emission signatures.
Conclusions. Most of the observables discussed in this article behave in the manner expected, given knowledge of the evolution of the parameters in the 3D simulations. Nevertheless, some intriguing observational signatures are present. Identifying regions of magnetic field complexity is somewhat possiblewhen waves are present although even then, simultaneous spectroscopic imaging from different lines is important to identify these locations. Care needs to be taken when interpreting signatures in the intensity and Doppler velocities as torsional motions as in our setup, such signatures were a consequence of the complex nature of the magnetic field rather than real torsional waves. Finally, we investigated the kinetic energy, estimated from the Doppler velocities, which is highly dependent on the polarisation of the wave, complexity of the background field and the LOS angles.
Close

Details

Original languageEnglish
Article numberA86
Number of pages15
JournalAstronomy & Astrophysics
Volume643
Early online date6 Nov 2020
DOIs
Publication statusPublished - Nov 2020

    Research areas

  • Sun: corona, Sun: magnetic fields, Sun: oscillations, Magnetohydrodyanmics (MHD)

Discover related content
Find related publications, people, projects and more using interactive charts.

View graph of relations

Related by author

  1. A fast multi-dimensional magnetohydrodynamic formulation of the transition region adaptive conduction (TRAC) method

    Johnston, C. D., Hood, A. W., De Moortel, I., Pagano, P. & Howson, T. A., Oct 2021, In: Astronomy & Astrophysics. 654, 16 p., A2.

    Research output: Contribution to journalArticlepeer-review

  2. Magnetic reconnection and the Kelvin-Helmholtz instability in the solar corona

    Howson, T. A., De Moortel, I. & Pontin, D., 24 Sep 2021, (Accepted/In press) In: Astronomy & Astrophysics.

    Research output: Contribution to journalArticlepeer-review

  3. Investigating coronal wave energy estimates using synthetic non-thermal line widths

    Fyfe, L., Howson, T. A., De Moortel, I., Pant, V. & Van Doorsselaere, T., 20 Sep 2021, (Accepted/In press) In: Astronomy & Astrophysics.

    Research output: Contribution to journalArticlepeer-review

  4. The effects of driving time scales on heating in a coronal arcade

    Howson, T. A., De Moortel, I. & Fyfe, L., Nov 2020, In: Astronomy & Astrophysics. 643, 13 p., A85.

    Research output: Contribution to journalArticlepeer-review

  5. Phase mixing and wave heating in a complex coronal plasma

    Howson, T. A., De Moortel, I. & Reid, J., Apr 2020, In: Astronomy & Astrophysics. 636, 13 p., A40.

    Research output: Contribution to journalArticlepeer-review

Related by journal

  1. A fast multi-dimensional magnetohydrodynamic formulation of the transition region adaptive conduction (TRAC) method

    Johnston, C. D., Hood, A. W., De Moortel, I., Pagano, P. & Howson, T. A., Oct 2021, In: Astronomy & Astrophysics. 654, 16 p., A2.

    Research output: Contribution to journalArticlepeer-review

  2. Dust in brown dwarfs and extra-solar planets: VIII. TiO2 seed formation: 3D Monte Carlo versus kinetic approach

    Kohn, C., Helling, C., Enghoff, M. B., Haynes, K., Sindel, JP., Krog, D. & Gobrecht, D., Oct 2021, In: Astronomy & Astrophysics. 654, 16 p., A120.

    Research output: Contribution to journalArticlepeer-review

  3. The HARPS search for southern extra-solar planets: XLVI. 12 super-Earths around the solar type stars HD 39194, HD 93385, HD 96700, HD 154088, and HD 189567

    Unger, N., Segransan, D., Queloz, D., Udry, S., Lovis, C., Mordasini, C., Ahrer, E., Benz, W., Bouchy, F., Delisle, JB., Diaz, RF., Dumusque, X., Lo Curto, G., Marmier, M., Mayor, M., Pepe, F., Santos, NC., Stalport, M., Alonso, R., Cameron, AC. & 6 others, Deleuil, M., Figueira, P., Gillon, M., Moutou, C., Pollacco, D. & Pompei, E., Oct 2021, In: Astronomy & Astrophysics. 654, 19 p., A104.

    Research output: Contribution to journalArticlepeer-review

  4. The changing face of AU Mic b: stellar spots, spin-orbit commensurability, and transit timing variations as seen by CHEOPS and TESS

    Szabo, G. M., Gandolfi, D., Brandeker, A., Csizmadia, S., Garai, Z., Billot, N., Broeg, C., Ehrenreich, D., Fortier, A., Fossati, L., Hoyer, S., Kiss, L., Lecavelier des Etangs, A., Maxted, PFL., Ribas, I., Alibert, Y., Alonso, R., Escude, GA., Barczy, T., Barros, SCC. & 61 others, Barrado, D., Baumjohann, W., Beck, M., Beck, T., Bekkelien, A., Bonfils, X., Benz, W., Borsato, L., Busch, MD., Cabrera, J., Charnoz, S., Cameron, AC., Van Damme, CC., Davies, MB., Delrez, L., Deleuil, M., Demangeon, ODS., Demory, BO., Erikson, A., Fridlund, M., Futyan, D., Muñoz, A. G., Gillon, M., Guedel, M., Guterman, P., Heng, K., Isaak, KG., Lacedelli, G., Laskar, J., Lendl, M., Lovis, C., Luntzer, A., Magrin, D., Nascimbeni, V., Olofsson, G., Osborn, HP., Ottensamer, R., Pagano, I., Palle, E., Peter, G., Piazza, D., Piotto, G., Pollacco, D., Queloz, D., Ragazzoni, R., Rando, N., Rauer, H., Santos, NC., Scandariato, G., Segransan, D., Serrano, LM., Sicilia, D., Simon, AE., Smith, AMS., Sousa, SG., Steller, M., Thomas, N., Udry, S., Van Grootel, V., Walton, NA. & Wilson, TG., Oct 2021, In: Astronomy & Astrophysics. 654, 15 p., A159.

    Research output: Contribution to journalArticlepeer-review

  5. Magnetic reconnection and the Kelvin-Helmholtz instability in the solar corona

    Howson, T. A., De Moortel, I. & Pontin, D., 24 Sep 2021, (Accepted/In press) In: Astronomy & Astrophysics.

    Research output: Contribution to journalArticlepeer-review

Related by journal

  1. Astronomy & Astrophysics (Journal)

    Duncan Hendry Mackay (Editor)

    2004 → …

    Activity: Publication peer-review and editorial work typesEditor of research journal

  2. Astronomy & Astrophysics (Journal)

    Christiane Helling (Editor)

    2000 → …

    Activity: Publication peer-review and editorial work typesEditor of research journal

  3. Astronomy & Astrophysics (Journal)

    Alan William Hood (Editor)

    1980 → …

    Activity: Publication peer-review and editorial work typesEditor of research journal

ID: 270210419

Top