%0 Journal Article
%@holdercode {isadg {BR SPINPE} ibi 8JMKD3MGPCW/3DT298S}
%@nexthigherunit 8JMKD3MGPCW/3EU29DP
%@archivingpolicy denypublisher denyfinaldraft
%X Turbulence and chaos play a fundamental role in stellar convective zones through the transport of particles, energy, and momentum, and in fast dynamos, through the stretching, twisting, and folding of magnetic flux tubes. A particularly revealing way to describe turbulent motions is through the analysis of Lagrangian coherent structures (LCSs), which are material lines or surfaces that act as transport barriers in the fluid. We report the detection of LCSs in helical MHD dynamo simulations with scale separation. In an Arnold-Beltrami-Childress flow, two dynamo regimes, a propagating coherent mean-field regime and an intermittent regime, are identified as the magnetic diffusivity is varied. The sharp contrast between the chaotic tangle of attracting and repelling LCSs in both regimes permits a unique analysis of the impact of the magnetic field on the velocity field. In a second example, LCSs reveal the link between the level of chaotic mixing of the velocity field and the saturation of a large-scale dynamo when the magnetic field exceeds the equipartition value.
%@mirrorrepository sid.inpe.br/mtc-m19@80/2009/08.21.17.02.53
%8 July
%N 1
%T Lagrangian coherent structures in nonlinear dynamos
%@electronicmailaddress rempel@ita.br
%@electronicmailaddress abraham.chian@gmail.com
%@electronicmailaddress brandenb@nordita.org
%@secondarytype PRE PI
%K chaos, dynamo, magnetohydrodynamics (MHD.
%@usergroup administrator
%@usergroup tereza@sid.inpe.br
%@usergroup marciana
%@group
%@group DGE-CEA-INPE-MCT-BR
%@e-mailaddress tereza@sid.inpe.br
%@secondarykey INPE--PRE/
%@issn 2041-8205
%@issn 2041-8213
%2 sid.inpe.br/mtc-m19/2011/11.25.13.17.57
%@affiliation Institute of Aeronautical Technology (ITA)
%@affiliation Instituto Nacional de Pesquisas Espaciais (INPE)
%@affiliation NORDITA, AlbaNova University Ctr, Stockholm, Sweden
%B Astrophysical Journal Letters
%@versiontype publisher
%P L9
%4 sid.inpe.br/mtc-m19/2011/11.25.13.17
%@documentstage not transferred
%D 2011
%V 735
%@doi 10.1088/2041-8205/735/1/L9
%A Rempel, E. L.,
%A Chian, A. C. L.,
%A Brandenburg, A.,
%@area CEA