Skip to content

Research at St Andrews

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

Research output: Contribution to journalArticlepeer-review

Author(s)

C. D. Johnston, A. W. Hood, I. De Moortel, P. Pagano, T. A. Howson

School/Research organisations

Abstract

We have demonstrated that the transition region adaptive conduction (TRAC) method permits fast and accurate numerical solutions of the field-aligned hydrodynamic equations, successfully removing the influence of numerical resolution on the coronal density response to impulsive heating. This is achieved by adjusting the parallel thermal conductivity, radiative loss, and heating rates to broaden the transition region (TR), below a global cutoff temperature, so that the steep gradients are spatially resolved even when using coarse numerical grids. Implementing the original 1D formulation of TRAC in multi-dimensional magnetohydrodynamic (MHD) models would require tracing a large number of magnetic field lines at every time step in order to prescribe a global cutoff temperature to each field line. In this paper, we present a highly efficient formulation of the TRAC method for use in multi-dimensional MHD simulations, which does not rely on field line tracing. In the TR, adaptive local cutoff temperatures are used instead of global cutoff temperatures to broaden any unresolved parts of the atmosphere. These local cutoff temperatures are calculated using only local grid cell quantities, enabling the MHD extension of TRAC to efficiently account for the magnetic field evolution, without tracing field lines. Consistent with analytical predictions, we show that this approach successfully preserves the properties of the original TRAC method. In particular, the total radiative losses and heating remain conserved under the MHD formulation. Results from 2D MHD simulations of impulsive heating in unsheared and sheared arcades of coronal loops are also presented. These simulations benchmark the MHD TRAC method against a series of 1D models and demonstrate the versatility and robustness of the method in multi-dimensional magnetic fields. We show, for the first time, that pressure differences, generated during the evaporation phase of impulsive heating events, can produce current layers that are significantly narrower than the transverse energy deposition.

Close

Details

Original languageEnglish
Article numberA2
Number of pages16
JournalAstronomy & Astrophysics
Volume654
Early online date1 Oct 2021
DOIs
Publication statusPublished - Oct 2021

    Research areas

  • Magnetohydrodynamics (MHD), Sun: transition region, Sun: corona, Sun: chromosphere, Sun: flares hydrodynamics

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

View graph of relations

Related by author

  1. Magnetohydrodynamic waves in braided magnetic fields

    Howson, T., De Moortel, I., Reid, J. & Hood, A., Sep 2019, In: Astronomy & Astrophysics. 629, p. 1-12 12 p., A60.

    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. Forward modelling of MHD Waves in braided magnetic fields

    Fyfe, L., Howson, T. A. & De Moortel, I., Nov 2020, In: Astronomy & Astrophysics. 643, 15 p., A86.

    Research output: Contribution to journalArticlepeer-review

Related by journal

  1. 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

  2. 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

  3. 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

  4. 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: 274841980

Top