Coronal mass ejections: a driver of severe space weather
Coronal mass ejections: a driver of severe space weather
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DOI：
10.1002/wea.2437
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发表时间：
2015-01
期刊：
影响因子：
1.9
通讯作者：
L. Green;D. Baker
中科院分区：
文献类型：
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作者：
L. Green;D. Baker
2015年1月。0,0,1日冕物质抛射与磁层。如果发生这种情况，日冕抛射的运动就会把昼侧磁层的通量拖到夜侧，磁层的这一部分就会发生磁通量的积累，随后就会发生磁重联。这种夜侧磁层的重新配置允许磁通量回到日侧，在那里它可以再次与日冕物质抛射重新连接。这个过程被称为邓吉循环（Dungey, 1961）。在这些时间里，磁层被驱动到一个紊乱的状态，产生地磁亚暴和风暴，然后导致大量的空间天气效应（Pulkkinen, 2007）。cme是磁化等离子体的大量抛射，通常在时间和空间上与另一种被称为太阳耀斑的太阳活动相关联——电磁辐射（十米无线电波到伽马射线）和高能粒子的突然爆发（Benz, 2008）。日冕物质抛射与耀斑的联系源于两种现象共同的物理过程。太阳耀斑是在磁重联过程中将磁能转换成其他形式而产生的，这种能量转换导致电磁辐射的产生。然而，在日冕抛射期间，磁重联也会重新配置磁场，加速磁化等离子体远离太阳。尽管有这些共同的方面，日冕物质抛射和耀斑在物理伪装方面是非常不同的。太阳耀斑通过电离地球上层大气的高能辐射，以及通过加速到接近相对论能量的质子，对太空中的航天器和人类构成威胁，从而对太空天气产生影响。
W ether – Jauary 215, ol. 0, o. 1 the CME with the magnetosphere. If this occurs, the dayside magnetospheric flux gets dragged over to the nightside by the motion of the CME, and an accumulation of magnetic flux then occurs in this part of the magnetosphere, followed by magnetic reconnection. This reconfiguration of the nightside magnetosphere allows magnetic flux to move back to the dayside, where it can undergo reconnection with the CME once again. This process is known as the Dungey cycle (Dungey, 1961). During these times the magnetosphere is driven into a disturbed state, producing geomagnetic sub-storms and storms which then lead to a multitude of space weather effects (Pulkkinen, 2007). CMEs, which are the bulk ejection of magnetised plasma, are often temporally and spatially associated with another form of solar activity known as a solar flare – sudden bursts of electromagnetic radiation (decametre radio waves to gamma-rays) and high-energy particles (Benz, 2008). This CME-flare association has its origins in the physical processes that are common to both phenomena. Solar flares arise from the conversion of magnetic energy into other forms during magnetic reconnection, and this energy conversion leads to the production of electromagnetic radiation. However, magnetic reconnection also reconfigures the magnetic field during a CME, which accelerates the magnetised plasma away from the Sun. Despite these common aspects, CMEs and flares are very distinct in terms of their physical guise. Solar flares have a space weather impact through their high-energy radiation that ionises the Earth’s upper atmosphere, and through the protons that are accelerated to near-relativistic energies, posing a threat to spacecraft and humans in space.