In situ detection of the electron diffusion region of collisionless magnetic reconnection at the high-latitude magnetopause

作     者：Qiu-Gang Zong Hui Zhang 

作者机构：Institute of Space Physics and Applied TechnologyPeking University Geophysical InstituteUniversity of Alaska Fairbanks 

出 版 物：《Earth and Planetary Physics》 (地球与行星物理（英文版）)

年 卷 期：2018年第2卷第3期

页      面：231-237页

学科分类：070802[理学-空间物理学] 07[理学] 0708[理学-地球物理学] 

基　　金：supported by National Natural Science Foundation of China(41421003 and 41627805) 

主　　题：electron diffusion region magnetic reconnection high-latitude magnetopause 

摘      要：Magnetic reconnection is the most fundamental energy-transfer mechanism in the universe that converts magnetic energy into heat and kinetic energy of charged *** reconnection to occur,the frozen-in condition must break down in a localized region,commonly called the ‘diffusion region .In Earth s magnetosphere,ion diffusion regions have already been observed,while electron diffusion regions have not been detected due to their small scales(of the order of a few km)(Paschmann,2008).In this paper we report,for the first time,in situ observations of an active electron diffusion region by the four Cluster spacecraft at the Earth s highlatitude *** electron diffusion region is characterized by nongyrotropic electron distribution,strong field-aligned currents carried by electrons and bi-directional super-Alfvénic electron *** observed were multiple micro-scale flux ropes,with a scale size of about 5 c/ω_(pe)(12 km,with c/ωpe the electron inertial length),that are crucial for electron acceleration in the guide-field reconnection process(Drake et al.,2006 a).The data demonstrate the existence of the electron diffusion region in collisionless guide-field reconnection at the magnetopause.