EDP Sciences
Free access
Volume 380, Number 2, December III 2001
Page(s) 734 - 738
Section Physical and chemical processes
DOI http://dx.doi.org/10.1051/0004-6361:20011397

A&A 380, 734-738 (2001)
DOI: 10.1051/0004-6361:20011397

Flux-loss of buoyant ropes interacting with convective flows

S. B. F. Dorch1, B. V. Gudiksen1, W. P. Abbett2 and Å. Nordlund3

1  The Royal Swedish Academy of Sciences, Stockholm Center for Physics, Astronomy and Biotechnology, 10691 Stockholm, Sweden
2  Space Sciences Laboratory, University of California, Berkeley, CA-94720-7450, USA
3  The Niels Bohr Institute for Astronomy, Physics and Geophysics, Juliane Maries Vej 30, 2100 Copenhagen Ø, Denmark

(Received 27 August 2001 / Accepted 2 October 2001)

We present 3-d numerical magneto-hydrodynamic simulations of a buoyant, twisted magnetic flux rope embedded in a stratified, solar-like model convection zone. The flux rope is given an initial twist such that it neither kinks nor fragments during its ascent. Moreover, its magnetic energy content with respect to convection is chosen so that the flux rope retains its basic geometry while being deflected from a purely vertical ascent by convective flows. The simulations show that magnetic flux is advected away from the core of the flux rope as it interacts with the convection. The results thus support the idea that the amount of toroidal flux stored at or near the bottom of the solar convection zone may currently be underestimated.

Key words: sun: magnetic fields -- interior -- granulation -- stars: magnetic fields

Offprint request: S. B. F. Dorch, dorch@astro.su.se

© ESO 2001