First Observations of the Disruption of the Earth's Foreshock Wave Field During Magnetic Clouds
First Observations of the Disruption of the Earth's Foreshock Wave Field During Magnetic Clouds
复制标题
磁云期间地球前震波场破坏的首次观测
DOI：
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复制
发表时间：
2019
影响因子：
5.2
通讯作者：
I. Dandouras
中科院分区：
文献类型：
--
作者：
L. Turc;O. Roberts;M. Archer;M. Palmroth;M. Battarbee;T. Brito;U. Ganse;M. Grandin;Y. Pfau‐Kempf;C. Escoubet;I. Dandouras
前震延伸到地球弓形激波的上游，是一个电磁波活动和非线性现象强烈的区域，可以对地球空间产生全球影响。这也是第一个地球物理区域遇到的太阳风扰动旅行到地球。在这里，我们提出了第一次观察到的相当大的修改前震波场在极端事件的太阳起源称为磁云。Cluster的多航天器数据显示，典型的准单色前震波可以完全被相互关联长度较短的波的叠加所取代。全球数值模拟进一步证实，前震波场在较小尺度上更加复杂和有组织。离子测量表明，激波反射粒子特性的变化可能导致波场的这些修改。这种前震状态只在地球发生极端事件时才会遇到，但强烈的磁场通常靠近太阳或其他恒星。
The foreshock, extending upstream of Earth's bow shock, is a region of intense electromagnetic wave activity and nonlinear phenomena, which can have global effects on geospace. It is also the first geophysical region encountered by solar wind disturbances journeying toward Earth. Here, we present the first observations of considerable modifications of the foreshock wave field during extreme events of solar origin called magnetic clouds. Cluster's multispacecraft data reveal that the typical quasi‐monochromatic foreshock waves can be completely replaced by a superposition of waves each with shorter correlation lengths. Global numerical simulations further confirm that the foreshock wave field is more intricate and organized at smaller scales. Ion measurements suggest that changes in shock‐reflected particle properties may cause these modifications of the wave field. This state of the foreshock is encountered only during extreme events at Earth, but intense magnetic fields are typical close to the Sun or other stars.
DOI：
10.1002/2015ja021526
发表时间：
2015-04
期刊：
Journal of Geophysical Research: Space Physics
影响因子：
--
作者：
M. Palmroth;M. Archer;R. Vainio;H. Hietala;Y. Pfau‐Kempf;S. Hoilijoki;O. Hannuksela;U. Ganse;A. Sandroos;S. Alfthan;J. Eastwood
通讯作者：
M. Palmroth;M. Archer;R. Vainio;H. Hietala;Y. Pfau‐Kempf;S. Hoilijoki;O. Hannuksela;U. Ganse;A. Sandroos;S. Alfthan;J. Eastwood