A Non-axisymmetric Spherical α~2-Dynamo

作     者：Jie Jiang Jing-Xiu Wang 

作者机构：National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 

出 版 物：《Chinese Journal of Astronomy and Astrophysics》 (中国天文和天体物理学报（英文版）)

年 卷 期：2006年第6卷第2期

页      面：227-236页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：Supported by the National Natural Science Foundation of China 

主　　题：stars: magnetic fields   methods: numerical 

摘      要：Using the Chebyshev-tau method, the generation of oscillatory nonaxisymmetric stellar magnetic fields by the α^2-dynamo is studied in spherical geometry. Following the boundary conditions given by Schubert ＆ Zhang, the spherical α^2-dynamo consists of a fully convective spherical shell with inner radius ri and outer radius ro. A comparison of the critical dynamo numbers of axisymmetric and φ-dependent modes for different thicknesses of the convective shell and different α- profiles leads to the following qualitative results： （i） when the angular factor of α- profile is sin^n θ cosθ （n= 1, 2, 4） the solutions of the α^2dynamo are oscillatory and non-axisymmetric, （ii） the thinner the convective shell, the more easily is the nonaxisymmetric mode excited and the higher is the latitudinal wave number, （iii） the thickness of the outer convective shell has an effect on the symmetries of the magnetic fields.