Non-uniformity effects in the negative effective magnetic pressure instability
2013 (English)In: Physica Scripta, ISSN 0031-8949, E-ISSN 1402-4896, Vol. T155, 014027- p.Article in journal (Refereed) Published
In direct numerical simulations of strongly stratified turbulence we have previously studied the development of large scale magnetic structures starting from a uniform background field. This is caused by an instability resulting from a negative contribution of small-scale turbulence to the effective (mean-field) magnetic pressure, and was qualitatively reproduced in mean-field simulations (MFS) where this pressure reduction was modeled as a function of the mean magnetic field normalized by the equipartition field. We now investigate the effect of mean current density on the turbulent pressure reduction. In our MFS, such currents are associated with sharp gradients of the growing structures. We find that an enhanced mean current density increases the suppression of the turbulent pressure.
Place, publisher, year, edition, pages
2013. Vol. T155, 014027- p.
IdentifiersURN: urn:nbn:se:su:diva-92806DOI: 10.1088/0031-8949/2013/T155/014027ISI: 000321863000029OAI: oai:DiVA.org:su-92806DiVA: diva2:642734
European Research Council 227952 227915; Swedish Research Council 621-2011-5076; COST Action MP0806; Government of the Russian Federation 11.G34.31.0048 2013-08-232013-08-202013-08-23Bibliographically approved