St Andrews Research Repository

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.

The heating of solar coronal loops by Alfvèn wave turbulence

View/Open
Voss_2017_AJ_WaveTurbulence_AAM.pdf (3.506Mb)
Date
30/10/2017
Author
van Ballegooijen, A. A.
Asgari-Targhi, M.
Voss, A.
Keywords
Magnetohydrodynamics (MHD)
Sun: corona
Sun: magnetic fields
Turbulence
Waves
QB Astronomy
QC Physics
NDAS
Metadata
Show full item record
Abstract
In this paper we further develop a model for the heating of coronal loops by Alfvèn wave turbulence (AWT). The Alfvèn waves are assumed to be launched from a collection of kilogauss flux tubes in the photosphere at the two ends of the loop. Using a three-dimensional magneto-hydrodynamic (MHD) model for an active-region loop, we investigate how the waves from neighboring flux tubes interact in the chromosphere and corona. For a particular combination of model parameters we find that AWT can produce enough heat to maintain a peak temperature of about 2.5 MK, somewhat lower than the temperatures of 3 – 4 MK observed in the cores of active regions. The heating rates vary strongly in space and time, but the simulated heating events have durations less than 1 minute and are unlikely to reproduce the observed broad Differential Emission Measure distributions of active regions. The simulated spectral line non-thermal widths are predicted to be about 27 km s−1, which is high compared to the observed values. Therefore, the present AWT model does not satisfy the observational constraints. An alternative “magnetic braiding” model is considered in which the coronal field lines are subject to slow random footpoint motions, but we find that such long period motions produce much less heating than the shorter period waves launched within the flux tubes. We discuss several possibilities for resolving the problem of producing sufficiently hot loops in active regions.
Citation
van Ballegooijen , A A , Asgari-Targhi , M & Voss , A 2017 , ' The heating of solar coronal loops by Alfvèn wave turbulence ' Astrophysical Journal , vol. 849 , no. 1 , 46 . DOI: 10.3847/1538-4357/aa9118
Publication
Astrophysical Journal
Status
Peer reviewed
DOI
https://doi.org/10.3847/1538-4357/aa9118
ISSN
0004-637X
Type
Journal article
Rights
© 2017 The American Astronomical Society. 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/10.3847/1538-4357/aa9118
Description
This project was supported under contract NNM07AB07C from NASA to the Smithsonian Astrophysical Observatory (SAO) and contract SP02H1701R from Lockheed Martin Space and Astrophysics Laboratory (LMSAL) to SAO.
Collections
  • Computer Science Research
  • University of St Andrews Research
URI
http://hdl.handle.net/10023/12261
https://arxiv.org/abs/1710.05074

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.

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