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.

A fast and accurate method to capture the solar corona/transition region enthalpy exchange

Thumbnail
View/Open
Johnston_2019_ApJL_873_L22_1_.pdf (3.040Mb)
Date
15/03/2019
Author
Johnston, C. D.
Bradshaw, S. J.
Keywords
Hydrodynamics
Magnetohydrodynamics (MHD)
Sun: chromosphere
Sun: corona
Sun: flares
Sun: transition region
QB Astronomy
T-NDAS
Metadata
Show full item record
Altmetrics Handle Statistics
Altmetrics DOI Statistics
Abstract
The brightness of the emission from coronal loops in the solar atmosphere is strongly dependent on the temperature and density of the confined plasma. After a release of energy, these loops undergo a heating and upflow phase, followed by a cooling and downflow cycle. Throughout, there are significant variations in the properties of the coronal plasma. In particular, the increased coronal temperature leads to an excess downward heat flux that the transition region (TR) is unable to radiate. This generates an enthalpy flux from the TR to the corona, increasing the coronal density. The enthalpy exchange is highly sensitive to the TR resolution in numerical simulations. With a numerically underresolved TR, major errors occur in simulating the coronal density evolution and, thus, the predicted loop emission. This Letter presents a new method that addresses the difficulty of obtaining the correct interaction between the corona and corona/chromosphere interface. In the TR, an adaptive thermal conduction approach is used that broadens any unresolved parts of the atmosphere. We show that this approach, referred to as TRAC, successfully removes the influence of numerical resolution on the coronal density response to heating while maintaining high levels of agreement with fully resolved models. When employed with coarse spatial resolutions, typically achieved in multidimensional MHD codes, the peak density errors are less than 3% and the computation time is three orders of magnitude faster than fully resolved field-aligned models. The advantages of using TRAC in field-aligned hydrodynamic and multidimensional magnetohydrodynamic simulations are discussed.
Citation
Johnston , C D & Bradshaw , S J 2019 , ' A fast and accurate method to capture the solar corona/transition region enthalpy exchange ' , Astrophysical Journal Letters , vol. 873 , no. 2 , L22 . https://doi.org/10.3847/2041-8213/ab0c1f
Publication
Astrophysical Journal Letters
Status
Peer reviewed
DOI
https://doi.org/10.3847/2041-8213/ab0c1f
ISSN
2041-8213
Type
Journal article
Rights
Copyright © 2019. The American Astronomical Society. All rights reserved. This work is made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at: https://doi.org/10.3847/2041-8213/ab0c1f
Description
This research has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation program (grant agreement No. 647214). S.J.B. is grateful to the National Science Foundation for supporting this work through CAREER award AGS-1450230. C.D.J. acknowledges support from the International Space Science Institute (ISSI), Bern, Switzerland to the International Team 401 “Observed Multi-Scale Variability of Coronal Loops as a Probe of Coronal Heating.”
Collections
  • University of St Andrews Research
URL
https://arxiv.org/abs/1903.01132
URI
http://hdl.handle.net/10023/17417

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