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dc.contributor.authorHowson, Thomas Alexander
dc.contributor.authorDe Moortel, Ineke
dc.identifier.citationHowson , T A & De Moortel , I 2022 , ' The effects of driving time scales on coronal heating in a stratified atmosphere ' , Astronomy & Astrophysics , vol. 661 , A144 .
dc.identifier.otherPURE: 279281881
dc.identifier.otherPURE UUID: 51892eaa-1d78-4039-8451-4185bbe39c5a
dc.identifier.otherScopus: 85130779408
dc.identifier.otherWOS: 000799616100011
dc.identifier.otherORCID: /0000-0002-4895-6277/work/124889197
dc.identifier.otherORCID: /0000-0002-1452-9330/work/124889552
dc.descriptionFunding: The research leading to these results has received funding from the UK Science and Technology Facilities Council (consolidated grant ST/N000609/1), the European Union Horizon 2020 research and innovation programme (grant agreement No. 647214). IDM received funding from the Research Council of Norway through its Centres of Excellence scheme, project number 262622. This work used the DiRAC Data Analytic system at the University of Cambridge, operated by the University of Cambridge High Performance Computing Service on behalf of the STFC DiRAC HPC Facility ( This equipment was funded by BIS National E-infrastructure capital grant (ST/K001590/1), STFC capital grants ST/H008861/1 and ST/H00887X/1, and STFC DiRAC Operations grant ST/K00333X/1. DiRAC is part of the National e-Infrastructure.en
dc.description.abstractAims: We investigate the atmospheric response to coronal heating driven by random flows with different characteristic time scales and amplitudes. Methods: We conducted a series of 3D MHD simulations of random driving imposed on a gravitationally stratified model of the solar atmosphere. In order to understand differences between alternating current (AC) and direct current (DC) heating, we considered the effects of changing the characteristic time scales of the imposed velocities. We also investigated the effects of the magnitude of the velocity driving. Results: In all cases, complex foot point motions lead to a proliferation of current sheets and energy dissipation throughout the corona. For a given amplitude, DC driving typically leads to a greater rate of energy injection when compared to AC driving. This leads to the formation of larger currents, increased heating rates and higher temperatures in DC simulations. There is no difference in the spatial distribution of energy dissipation across simulations, however, energy release events in AC cases tend to be more frequent and last for less time than in DC cases. Higher velocity driving is associated with larger currents, higher temperatures and the corona occupying a larger fraction of the simulation volume. In all cases, most of heating is associated with small energy release events, which occur much more frequently than large events. Conclusions: When combined with observational results showing a greater abundance of power in low frequency modes, these findings suggest that energy release in the corona is likely to be driven by longer time scale motions. In the corona, AC and DC driving occur concurrently and their effects remain difficult to isolate. The distribution of field line temperatures and the asymmetry of temperature profiles may reveal the frequency and longevity of energy release events and therefore the relative importance of AC and DC heating.
dc.relation.ispartofAstronomy & Astrophysicsen
dc.rightsCopyright © 2022 ESO. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the final published version of the work, which was originally published at
dc.subjectSun: coronaen
dc.subjectSun: magnetic fieldsen
dc.subjectMagnetohydrodynamics (MHD)en
dc.subjectSun: atmosphereen
dc.subjectQB Astronomyen
dc.subjectQC Physicsen
dc.titleThe effects of driving time scales on coronal heating in a stratified atmosphereen
dc.typeJournal articleen
dc.contributor.sponsorEuropean Research Councilen
dc.contributor.sponsorScience & Technology Facilities Councilen
dc.contributor.sponsorScience & Technology Facilities Councilen
dc.description.versionPublisher PDFen
dc.contributor.institutionUniversity of St Andrews. Applied Mathematicsen
dc.contributor.institutionUniversity of St Andrews. Office of the Principalen
dc.description.statusPeer revieweden

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