Alfvénic Fluctuations in an Interplanetary Coronal Mass Ejection Observed Near 1 AU
Alfvénic Fluctuations in an Interplanetary Coronal Mass Ejection Observed Near 1 AU
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DOI：
10.1088/1009-0630/14/2/04
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发表时间：
2012-02
影响因子：
1.7
通讯作者：
Haoming Liang;C. Xiao;Guiping Zhou;Z. Pu;Honggang Wang;Xiaogang Wang
中科院分区：
文献类型：
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作者：
Haoming Liang;C. Xiao;Guiping Zhou;Z. Pu;Honggang Wang;Xiaogang Wang
就目前日冕物质抛射(CME)触发模型而言，不同模型的磁绳中Alfv、N波的分布是不同的，因此考察行星际日冕物质抛射(ICME)中的Alfv、N波分布是将ICME观测结果与CME触发理论模型联系起来的有效途径。然而，以往观测到的ICME中的Alfv？NIC波动很少，位置仅在0.3AU到0.68AU之间，这通常被解释为这些残余波的迅速消散。本文介绍了2011年2月17~20日由风在1AU附近的磁云(MC)中观测到的Alfv？n波。太阳活动中心是由日冕物质抛射伴随着第24太阳周的第一次X级耀斑产生的。磁涨落功率谱密度的斜率与周围太阳风中的模式相似，但更具各向异性。这些结果也将有助于CME理论和ICME热力学的研究。
As for the present situation of coronal mass ejection (CME) triggering models, the distributions of Alfv?n waves in flux ropes are different from model to model, and thus examining those distributions in interplanetary coronal mass ejection (ICME) is an effective way to connect ICME observations with these theoretical models of CME triggering. However, previous observations of Alfv?nic fluctuations in ICMEs were rare with locations ranging from 0.3 AU to 0.68 AU only, which is usually explained as rapid dissipation of those remnant waves. Here we present an observation of Alfv?n waves in a magnetic cloud (MC) near 1 AU, in situ detected by WIND in February 17~20, 2011. The MC was generated by a CME accompanied with the first X-class flare in the 24th solar cycle. The slope of the power spectral densities of magnetic fluctuation in the MC, are similar to those modes in ambient solar wind, but more anisotropic. The results will also be helpful for studies of CME theories and ICME thermodynamics.