Structures of magnetic null points in reconnection diffusion region:Cluster observations  

作　　者：HU YunHui DENG XiaoHua ZHOU Meng TANG RongXin ZHAO Hui FU Song SU ZhiWen WANG JingFang YUAN ZhiGang R. NAKAMURA W. BAUMJOHANN H. REME C. M. CARR 

机构地区：[1]School of Electronic Information, State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China [2]State Key Laboratory of Space Weather, Chinese Academy of Sciences, Beijing 100012, China [3]Space Research Institute, Austrian Academy of Sciences, 6, A-8042 Graz, Austria [4]Centre d'Etudes Spatiale des Rayonnements, BP 4346, 31028 Toulouse Cedex 4, France [5]The Blackett Laboratory, Imperial College London SW7 2BZ, UK

出　　处：《Chinese Science Bulletin》2008年第12期1880-1886,共7页

基　　金：the National Natural Science Foundation of China (Grant Nos.40390153,40574073,40574074,40640420563)the Outstanding Young Scien-tists Founding of China (Grant No.40325012)

摘　　要：Magnetic reconnection is a very important and fundamental plasma process in transferring energy from magnetic field into plasma. Previous theory, numerical simulations and observations mostly concen-trate on 2-dimensional (2D) model; however, magnetic reconnection is a 3-dimensional (3D) nonlinear process in nature. The properties of reconnection in 3D and its associated singular structure have not been resolved completely. Here we investigate the structures and characteristics of null points inside the reconnection diffusion region by introducing the discretized Poincaré index through Gauss integral and using magnetic field data with high resolution from the four satellites of Cluster mission. We esti-mate the velocity and trajectory of null points by calculating its position in different times, and compare and discuss the observations with different reconnection models with null points based on character-istics of electric current around null points.Magnetic reconnection is a very important and fundamental plasma process in transferring energy from magnetic field into plasma. Previous theory, numerical simulations and observations mostly concentrate on 2-dimensional （2D） model; however, magnetic reconnection is a 3-dimensional （3D） nonlinear process in nature. The properties of reconnection in 3D and its associated singular structure have not been resolved completely. Here we investigate the structures and charactedstics of null points inside the reconnection diffusion region by introducing the discretized Poincar6 index through Gauss integral and using magnetic field data with high resolution from the four satellites of Cluster mission. We estimate the velocity and trajectory of null points by calculating its position in different times, and compare and discuss the observations with different reconnection models with null points based on characteristics of electric current around null points.

关 键 词：三维磁零点 扩散现象 等离子体 能量转换 

分 类 号：O53[理学—等离子体物理]