Ooty Interplanetary Scintillation – Remote-Sensing Observations and Analysis of Coronal Mass Ejections in the Heliosphere
Ooty Interplanetary Scintillation – Remote-Sensing Observations and Analysis of Coronal Mass Ejections in the Heliosphere
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DOI：
10.1007/s11207-010-9593-5
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发表时间：
2010-07
期刊：
影响因子：
2.8
通讯作者：
P. K. Manoharan
中科院分区：
文献类型：
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作者：
P. K. Manoharan
在这篇论文中，我研究了与日冕物质抛射（CME）有关的太阳风密度和速度分布的三维演化。本研究中使用的主要太阳风数据是从Ooty射电望远镜的行星际闪烁测量中获得的，该望远镜能够每天测量大量射电源的闪烁，并能够沿日光层的沿着不同切面估计太阳风，从而能够重建日光层内层传播瞬变的三维结构。本研究的结果是：i）三维IPS图像可能显示与CME相关的磁通绳结构及其径向尺寸演化的证据; CME内的整体尺寸和特征在很大程度上取决于CME所携带的磁能。这样一个充满磁性的日冕物质抛射可能会引起强烈的磁暴，即使日冕物质抛射的拖尾部分穿过地球;ii）IPS测量沿着径向的日冕物质抛射在120 R显示密度湍流增强与冲击前方的日冕物质抛射和日冕物质抛射的核心。地核的密度随距离的增加而减小，表明日冕物质抛射的扩张。然而，与激波相关的密度随着与太阳的距离而增加，这表明在CME的前缘有一个强烈的压缩。120 R和1 Au之间距离的增加与CME的减速和激波的继续向外扩张是一致的。研究的关键是瞬态所具有的磁能决定了瞬态的径向演化。
In this paper, I investigate the three-dimensional evolution of solar wind density and speed distributions associated with coronal mass ejections (CMEs). The primary solar wind data used in this study has been obtained from the interplanetary scintillation (IPS) measurements made at the Ooty Radio Telescope, which is capable of measuring scintillation of a large number of radio sources per day and solar wind estimates along different cuts of the heliosphere that allow the reconstruction of three-dimensional structures of propagating transients in the inner heliosphere. The results of this study are:i) three-dimensional IPS images possibly show evidence for the flux-rope structure associated with the CME and its radial size evolution; the overall size and features within the CME are largely determined by the magnetic energy carried by the CME. Such a magnetically energetic CME can cause an intense geomagnetic storm, even if the trailing part of the CME passes through the Earth;ii) IPS measurements along the radial direction of a CME at ∼ 120 R⊙show density turbulence enhancements linked to the shock ahead of the CME and the core of the CME. The density of the core decreases with distance, suggesting the expansion of the CME. However, the density associated with the shock increases with distance from the Sun, indicating the development of a strong compression at the leading edge of the CME. The increase of stand-off distance between ∼ 120 R⊙and 1 AU is consistent with the deceleration of the CME and the continued outward expansion of the shock. The key point in this study is that the magnetic energy possessed by the transient determines its radial evolution.