MHD and kinetic analysis of flow bursts in the Earth's plasma sheet  

作　　者：MA YuDuan CAO JinBin FU HuiShan REME H. DANDOURAS I. YANG JunYing WANG ZhiQiang TAO Dan YANG Jian 

机构地区：[1]School of Astronautics, Beihang University [2]SOA Key Laboratory for Polar Science,Polar Research Institute of China [3]University of Toulouse,UPS-OMP, IRAP, Toulouse 31028, France [4]The French National Centre for Scientific Research, The Research Institute in Astrophysics and Planetology, BP 44346,F-31028, Toulouse cedex 4, France [5]Nanjing University of Aeronautics and Astronautics

出　　处：《Science China(Technological Sciences)》2014年第1期55-66,共12页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.40931054,41174141 and 40904042);the National Basic Research Program of China("973"Project)(Grant No.2011CB811404);Specialized Research Fund for State Key Laboratories of China(Grant No.KP201104)

摘　　要：In an attempt to study the flow bursts in the Earth＇s plasma sheet we select an event that took place on August 7, 2004 in the expansion phase of a substorm, using data from the geomagnetic index, solar wind data, plasma and magnetic field observa- tions from C1 Cluster satellite （the Cluster mission has 4 satellites） and from Double Star TC-1 satellite. In MHD approach, TC-1 firstly observed the tailward flow, then the earthward, and finally the flow altemated in two directions. C1 firstly ob- served the earthward plasma flow, and then the tailward plasma flow. Before flow bursts are observed by TC-1 and C1, there are disturbances in local entropy with their tailward local entropy larger than those of the earthward. The kinetic features of the plasma flow observed by C1 are similar to those in MHD. However, kinetic characteristics of the plasma flow observed by TC-1 are far more than the description in MHD. The inadequacy mainly exists in two cases： （i） the firstly enhanced tailward flows given in MHD are found without significant increase of the energetic tailward flux; （ii） the almost stagnant flow in MHD is composed of the enhanced energetic ion flux in both earthward and tailward directions. The earthward flow burst observed by TC-1 might be multiple overshoots and rebounds. The earthward flow burst observed by C1 might be simply rebounded in the near-Earth. The pulsation observed by C1 is earlier than that observed by TC-1 with the former intensity less than that of the latter. After the energetic ion flux in the tailward direction is significantly enhanced, the power spectrum intensity of the ULF wave commences to increase obviously, which may suggest that the stream instability is closely correlated with ULF pulsations.

关 键 词：MHD KINETIC FLUX ENTROPY 

分 类 号：P183[天文地球—天文学]