中文摘要：

地磁暴的行星际源研究是了解及预报地磁暴的关键因素之一．本文研究了2007-2012年间的所有Dstmin≤-50nT的中等以上地磁暴，建立了这些地磁暴及其行星际源的列表．在这6年中，共发生了51次Dstmin≤-50nT的中等以上地磁暴，其中9次为Dstmin≤-100nT的强地磁暴事件．对比上一活动周相同时间段发现，在这段太阳活动极低的时间，地磁暴的数目显著减少．对这些地磁暴行星际源的分析表明，65％的中等以上地磁暴由与日冕物质抛射相关的行星际结构引起，31％的地磁暴由共转相互作用区引起，这与以前的结果一致．特别的，在这个太阳活动极低时期内，共转相互作用区没有引起Dstmin≤-100nT的强地磁暴，同时，日冕物质抛射相关结构也没有引起Dstmin≤-200nT的超强地磁暴．以上结果表明极低太阳活动同时导致了共转相互作用区和日冕物质抛射地磁效应的减弱．进一步，分析不同太阳活动期间地磁暴的行星际源发现：在太阳活动低年（2007-2009年），共转相互作用区是引起地磁暴的主要原因；而在太阳活动上升期和高年（2010-2013年），大部分（75％，30／40）的中等以上地磁暴均由日冕物质抛射相关结构引起．

英文摘要：

Previous results show that various interplanetary structures, such as interplanetary coronal mass ejections （ICMEs） and corotating interaction regions （CIRs）, may contain the southward component of the magnetic field. Thus, all these structures are thought to be the interplanetary origins of the geomagnetic storm. In this paper, all moderate and strong geomagnetic storms with Dstmmin≤- 50 nT between 2007 and 2012 are studied. During this period, there are total 51 geomagnetic storms, in which 9 geomagnetic storms are strong events with Dstmin≤-100 nT. The number of the geomagnetic storm during this period is much smaller than similar period of 1996--2001 in the previous solar cycle. In addition, the interplanetary origins of these geomagnetic storms are identified based on the in-situ observations from WIND and ACE. It is found that 65% geomagnetic storms with Dstmin≤-50 nT were caused by the structures related to coronal mass ejections （CMEs）, and 31% were caused by corotating interaction regions （CIRs）. It should be noted that in this period, the CME related structures did not produce any extreme strong geomagnetic storm with Dstmin≤--200 nT and the CIR did not cause the strong geomagnetic storm with Dstmin≤- 100 nT. These results suggest that the geoeffectiveness of the CME and CIR is weak in this period. Furthermore, we found that the CIRs were the main cause of geomagnetic storms in solar minimum while CMEs-related structures were the main cause of geomagnetic storm in the rising phase and solar maximum.