St Andrews Research Repository

St Andrews University Home
View Item 
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  •   St Andrews Research Repository
  • University of St Andrews Research
  • University of St Andrews Research
  • University of St Andrews Research
  • View Item
  • Login
JavaScript is disabled for your browser. Some features of this site may not work without it.

Comparison of methods for modelling coronal magnetic fields

Thumbnail
View/Open
Goldstraw_2017_Comparison_methods_A_A_AAM.pdf (365.8Kb)
Date
26/02/2018
Author
Goldstraw, E. E.
Hood, A. W.
Browning, P. K.
Cargill, P. J.
Keywords
Sun: corona
Sun: magnetic fields
Magnetohydrodynamics (MHD)
QB Astronomy
QC Physics
3rd-NDAS
Metadata
Show full item record
Altmetrics Handle Statistics
Altmetrics DOI Statistics
Abstract
Aims. Four different approximate approaches used to model the stressing of coronal magnetic fields due to an imposed photospheric motion are compared with each other and the results from a full time-dependent magnetohydrodynamic (MHD) code. The assumptions used for each of the approximate methods are tested by considering large photospheric footpoint displacements. Methods. We consider a simple model problem, comparing the full nonlinear magnetohydrodynamic evolution, determined with the Lare2D numerical code, with four approximate approaches. Two of these,magneto-frictional relaxation and a quasi-1D Grad-Shafranov approach, assume sequences of equilibria, whilst the other two methods, a second-order linearisation of the MHD equations and Reduced MHD, are time-dependent. Results. The relaxation method is very accurate compared to full MHD for force-free equilibria for all footpoint displacements but has significant errors when the plasma β0 is of order unity. The 1D approach gives an extremely accurate description of the equilibria away from the photospheric boundary layers, and agrees well with Lare2D for all parameter values tested. The linearised MHD equations correctly predict the existence of photospheric boundary layers that are present in the full MHD results. As soon as the footpoint displacement becomes a significant fraction of the loop length, the RMHD method fails to model the sequences of equilibria correctly. The full numerical solution is interesting in its own right, and care must be taken for low β0 plasmas if the viscosity is too high.
Citation
Goldstraw , E E , Hood , A W , Browning , P K & Cargill , P J 2018 , ' Comparison of methods for modelling coronal magnetic fields ' , Astronomy & Astrophysics , vol. 610 , A48 . https://doi.org/10.1051/0004-6361/201731069
Publication
Astronomy & Astrophysics
Status
Peer reviewed
DOI
https://doi.org/10.1051/0004-6361/201731069
ISSN
0004-6361
Type
Journal article
Rights
© 2017, ESO. This work has been made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1051/0004-6361/201731069
Description
Funding: STFC through the Consolidated grant ST/N000609/1 (AWH); STFC studentship, ST/I505999/1 (EEG).
Collections
  • University of St Andrews Research
URL
http://adsabs.harvard.edu/abs/2017arXiv171107458G
URI
http://hdl.handle.net/10023/12438

Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.

Advanced Search

Browse

All of RepositoryCommunities & CollectionsBy Issue DateNamesTitlesSubjectsClassificationTypeFunderThis CollectionBy Issue DateNamesTitlesSubjectsClassificationTypeFunder

My Account

Login

Open Access

To find out how you can benefit from open access to research, see our library web pages and Open Access blog. For open access help contact: openaccess@st-andrews.ac.uk.

Accessibility

Read our Accessibility statement.

How to submit research papers

The full text of research papers can be submitted to the repository via Pure, the University's research information system. For help see our guide: How to deposit in Pure.

Electronic thesis deposit

Help with deposit.

Repository help

For repository help contact: Digital-Repository@st-andrews.ac.uk.

Give Feedback

Cookie policy

This site may use cookies. Please see Terms and Conditions.

Usage statistics

COUNTER-compliant statistics on downloads from the repository are available from the IRUS-UK Service. Contact us for information.

© University of St Andrews Library

University of St Andrews is a charity registered in Scotland, No SC013532.

  • Facebook
  • Twitter