ON THE EFFECTS OF A WEAK MAGNETIC-FIELD ON TURBULENT TRANSPORT

被引:69
作者
CATTANEO, F
机构
[1] Dept. of Astronomy and Astrophysics, University of Chicago, Chicago, IL 60637
关键词
DIFFUSION; MHD; TURBULENCE;
D O I
10.1086/174717
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We discuss the effects of a weak large-scale magnetic field on turbulent transport. We show by. means of a series of two-dimensional numerical experiments that turbulent diffusion can be effectively suppressed by a (large-scale) magnetic held whose energy is small compared to equipartition. The suppression mechanism is associated with a subtle modification of the Lagrangian energy spectrum, and it does not require any substantial reduction of the turbulent amplitude. We exploit the relation between diffusion and random walking to emphasize that the effect of a large-scale magnetic field is to induce a long-term memory in the field of turbulence. The implications for the general case of three-dimensional transport are briefly discussed.
引用
收藏
页码:200 / 205
页数:6
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