A New Method of Identifying 3D Null Points in Solar Vector Magnetic Fields

作     者：Hui Zhao Jing-Xiu Wang Jun Zhang Chi-Jie Xiao 

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：2005年第5卷第5期

页      面：443-447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：Sun: flares   Sun: corona  Sun: magnetic fields 

摘      要：Employing the Poincar6 index of isolated null-points in a vector field, we worked out a mathematical method of searching for 3D null-points in coronal magnetic fields. After introducing the relevant differential topology, we test the method by using the analytical model of Brown ＆ Priest. The location of nullpoint identified by our method coincides precisely with the analytical solution. Finally we apply the method to the 3D coronal magnetic fields reconstructed from an observed MDI magnetogram of a super-active region （NOAA 10488）. We find that the 3D null-point seems to be a key element in the magnetic topology associated with flare occurrence.