共 29 条
Formation of buoyant magnetic structures by a localized velocity shear
被引:26
作者:
Brummell, N
[1
]
Cline, K
Cattaneo, F
机构:
[1] Joint Inst Lab Astrophys, Boulder, CO 80309 USA
[2] Univ Colorado, Dept Astrophys & Planetary Sci, Boulder, CO 80309 USA
[3] Univ Chicago, Dept Math, Chicago, IL 60637 USA
关键词:
MHD;
Sun : interior;
Sun : magnetic fields;
stars : spots;
D O I:
10.1046/j.1365-8711.2002.05183.x
中图分类号:
P1 [天文学];
学科分类号:
0704 ;
摘要:
Motivated by considerations of the solar tachocline, we study the generation of strong buoyant magnetic structures by a sheared velocity field localized in a convectively stable background, using non-linear three-dimensional (3D) magnetohydrodynamic (MHD) simulations. The shear flow can spontaneously create strong tube-like toroidal (streamwise) magnetic structures from an imposed weak uniform poloidal (cross-stream) magnetic field. The structures are magnetically buoyant and therefore rise, and may evolve further to a rich variety of geometries, including kinked or arched shapes. The emergence process can repeat indefinitely with a characteristic period. These mechanisms may be relevant to the MHD processes in the solar tachocline and the creation and emergence of solar active regions.
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页码:L73 / U2
页数:6
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