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本文通过对TC-2卫星上搭载的中性原子成像仪(NUADU)在2004年11月发生的一次大磁暴期间观测到的一系列中性原子(ENA)图像的分析,试图给出环电流在磁暴期间的演化模式.研究表明,南向的行星际磁场(IMF)分量在离子从磁尾向内磁层注入和随后的环电流增长过程中起着关键的作用.IMF转为北向后,离子注入随即很快停止.在离子注入增强期间,离子的漂移路径是开放的,以致大量环电流离子从黄昏侧注入后快速地损失在黄昏至正午的磁层顶.所以,环电流往往在离子漂移路径从开放变为封闭后才达到最大强度,而不是在这之前,尽管那时的离子注入强度更大.在该磁暴主相期间,离子注入发生在17:00～22:00LT范围内,形成极其不对称的环电流分布形态.而在恢复相期间,由于受大的IMF B_y分量的影响,离子注入区的地方时分布范围东向扩张.对称环电流在磁尾对流减小、离子漂移路径变为封闭形态之后形成.在磁暴恢复相后期,从ENA图像看环电流基本衰减到平静时期的水平,而Dst指数仍然显示较强的磁扰动,这说明越尾电流对Dst指数有很重要的影响.
In this paper, an analysis of a series of neutral atom (ENA) images observed during a large magnetosphere occurred in November 2004 by a Neutral Atomic Imager (NUADU) mounted on the TC-2 satellite is attempted to give a brief introduction of the ring current It is shown that the IMFs in the south direction play a key role in the ionospheric magnetic field injection from the magnetotail and the subsequent increase of the ring current.If the IMF is shifted to the north, The injection soon stops. During the enhancement of ion implantation, the drift path of the ions is open, so that a large amount of ring current ions rapidly lose from the dusk to noon at the top of the magnetosphere after being injected from the dusk side. Therefore, The path reached its maximum intensity from open to closed, not before, despite the greater intensity of ion implantation at that time. During the main phase of the storms, ion implantation took place in the range of 17: 00-22: 00LT Extremely asymmetric ring current distribution pattern, while the region of the ion implantation region expands eastward due to the large IMF B_y component during the recovery phase.The symmetric ring current decreases at the magnetic tail convection and the ion drift path After the magnetic storm was restored, the ring current decayed to a quiet period from the ENA image, while the Dst index still showed a strong magnetic perturbation, indicating that the tail current is very important for the Dst index influences.