摘要
Using magnetic field and plasma data acquired with Cluster spacecrafts,we investigate the relationship between the field-aligned currents(FACs)at the plasma sheet boundary layer(PSBL)and solar wind dynamic pressure,as well as the interplanetary magnetic field(IMF)By on 17 August 2001 storm.Our studies reveal that FAC density at the PSBL in the magnetotail in the storm time is controlled mainly by the solar wind dynamic pressure rather than IMF By.The FACs at the PSBL are associated with the low−altitude region-1 current and have the same polarity as region-1 current in the dawn sector.In the polar region,the footprints of the FACs at the PSBL expand equatorward.The data analysis also shows that a very strong FAC with a density over 40 nA·m^(−2) appeared in this storm time when a substorm just occurred.
作者
程征伟
史建魁
张铁龙
王胜国
刘振兴
CHENG Zheng-Wei;SHI Jian-Kui;ZHANG Tie-Long;WANG Sheng-Guo;LIU Zhen-Xing(State Key Laboratory of Space Weather,CSSAR/CAS,Beijing 100190;Space Research Institute,Austrian Academy of Sciences,Graz,Austria;Beijing Institute of Applied Meteorology,Beijing 100083)
基金
by the National Natural Science Foundation of China under Grant Nos 40804031,40874084 and 40921063
the Specialized Research Fund for State Key Laboratories。