Influence of non-potential coronal magnetic topology on solar wind models
Abstract
By comparing a magneto-frictional model of the low coronal magnetic field to a potential field source surface model, we investigate the possible impact of non-potential magnetic structure on empirical solar wind models. These empirical models (such as Wang-Sheeley-Arge) estimate the distribution of solar wind speed solely from the magnetic field structure in the low corona. Our models are computed in a domain between the solar surface and 2.5 solar radii, and are extended to 0.1 AU using a Schatten current sheet model. The non-potential field has a more complex magnetic skeleton and quasi-separatrix structures than the potential field, leading to different sub-structure in the solar wind speed proxies. It contains twisted magnetic structures which can perturb the separatrix surfaces traced down from the base of the heliospheric current sheet. A significant difference between the models is the greater amount of open magnetic flux in the non-potential model. Using existing empirical formulae this leads to higher predicted wind speeds for two reasons: partly because magnetic flux tubes expand less rapidly with height, but more importantly because more open field lines are further from coronal hole boundaries.
Citation
Edwards , S J , Yeates , A R , Bocquet , F & Mackay , D H 2015 , ' Influence of non-potential coronal magnetic topology on solar wind models ' , Solar Physics , vol. 290 , no. 10 , pp. 2791-2808 . https://doi.org/10.1007/s11207-015-0795-8
Publication
Solar Physics
Status
Peer reviewed
ISSN
0038-0938Type
Journal article
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