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dc.contributor.authorMeyer, Karen Alison
dc.contributor.authorMackay, Duncan Hendry
dc.identifier.citationMeyer , K A & Mackay , D H 2016 , ' Modeling the sun's small-scale global photospheric magnetic field ' , Astrophysical Journal , vol. 830 , no. 2 , 160 , pp. 1-13 .
dc.identifier.otherPURE: 244441613
dc.identifier.otherPURE UUID: 2aae8b18-67fd-42d8-8b64-68fce3bc9c40
dc.identifier.otherScopus: 84992744455
dc.identifier.otherORCID: /0000-0001-6065-8531/work/58055457
dc.identifier.otherWOS: 000386583400012
dc.description.abstractWe present a new model for the Sun's global photospheric magnetic field during a deep minimum of activity, in which no active regions emerge. The emergence and subsequent evolution of small-scale magnetic features across the full solar surface is simulated, subject to the influence of a global supergranular flow pattern. Visually, the resulting simulated magnetograms reproduce the typical structure and scale observed in quiet Sun magnetograms. Quantitatively, the simulation quickly reaches a steady state, resulting in a mean field and flux distribution that are in good agreement with those determined from observations. A potential coronal magnetic field is extrapolated from the simulated full Sun magnetograms to consider the implications of such a quiet photospheric magnetic field on the corona and inner heliosphere. The bulk of the coronal magnetic field closes very low down, in short connections between small-scale features in the simulated magnetic network. Just 0.1% of the photospheric magnetic flux is found to be open at 2.5 R⊙, around 10–100 times less than that determined for typical Helioseismic and Magnetic Imager synoptic map observations. If such conditions were to exist on the Sun, this would lead to a significantly weaker interplanetary magnetic field than is currently observed, and hence a much higher cosmic ray flux at Earth.
dc.relation.ispartofAstrophysical Journalen
dc.rights© 2016, The American Astronomical Society. This work has been made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at /
dc.subjectSun: activityen
dc.subjectSun: coronaen
dc.subjectSun: magnetic fieldsen
dc.subjectSun: photosphereen
dc.subjectQB Astronomyen
dc.subjectQC Physicsen
dc.titleModeling the sun's small-scale global photospheric magnetic fielden
dc.typeJournal articleen
dc.contributor.sponsorThe Leverhulme Trusten
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.description.statusPeer revieweden

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