Plasmaspheric trough evolution under different conditions of subauroral ion drift  

作　　者：HE Fei ZHANG XiaoXin CHEN Bo FOK MeiChing 

机构地区：[1]Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China [2]National Center for Space Weather,China Meteorological Administration,Beijing 100081,China [3]NASA Goddard Space Flight Center,Greenbelt,MD 20771,USA

出　　处：《Science China(Technological Sciences)》2012年第5期1287-1294,共8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. 40890160, 40804030, 10878004, and 40974093);the National Basic Research Program of China ("973" Program) (Grant No. 2011CB811400, 2012CB957800);the National Hi-Tech Research and Development Program of China ("863" Program) (Grant No. 2010AA-122205);the Special Fund for Public Welfare Industry (Grant Nos. GYHY200806024 and GYHY200906013)

摘　　要：The statistical characteristics of the subauroral ion drift (SAID) in the ionosphere and the plasmaspheric trough evolution under different conditions of SAID were investigated in this paper, based on 566 SAID events observed by Akebono, Astrid-2, DE-2, and Freja satellites. The relationships between the latitudinal location of SAID and the Kp, AL, and Dst indices for these events were also discussed. It was found that the SAID events happened mainly at invariant latitude (ILAT) of 60.4° and magnetic local time (MLT) of 21.6 MLT and that 92.4% of the events happened when the Kp index was below 5.0, indicating a medium geomagnetic activity. The latitudinal half-width of SAID varied from 0.5° to 3.0° with a typical half-width of 1.0°. The SAID would happen at low latitudes if the geomagnetic activity was high. The effects of SAID on equatorial outer plas- masphere trough evolutions were studied with the dynamic global core plasma model (DGCPM) driven by the statistical results of SAID signatures. It was noted that locations, shapes and density of troughs vary with ILAT, MLT, latitudinal width, cross polar cap potential and lifetime of SAID events. The evolution of a trough is determined by the extent of SAID electric field penetrating into plasmasphere and not all SAID events can result in trough formations.

关 键 词：subauroral ion drift plasmaspheric trough dynamic global core plasma model simulation 

分 类 号：P352[天文地球—空间物理学]