The differences between storms driven by helmet streamer CIRs and storms driven by pseudostreamer CIRs
The differences between storms driven by helmet streamer CIRs and storms driven by pseudostreamer CIRs
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DOI：
10.1002/jgra.50524
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发表时间：
2013-09
期刊：
影响因子：
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通讯作者：
J. Borovsky;M. Denton
中科院分区：
文献类型：
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作者：
J. Borovsky;M. Denton
当快日冕洞源太阳风超过慢日冕洞源太阳风，形成一个压缩等离子体和磁场区域时，就形成了一个共转相互作用区（CIR）。冕洞快风上游的慢风可以是盔状流源，也可以是伪流源。对于125个CIR驱动的磁暴的集合，检查每个CIR前面的慢风;对于那些不包含喷出物的风暴，每个CIR被分类为头盔流光CIR（125个风暴中的74个）或伪流光CIR（125个风暴中的11个）。对这两组进行单独的叠加历元研究，以辨别由伪拖缆CIR驱动的风暴和由头盔拖缆CIR驱动的风暴之间的差异。一个主要的区别是，伪流光CIR风暴在风暴之前往往没有平静，因此外部等离子体在风暴开始之前不会重新填充，外部电子辐射带不会表现出风暴前的衰变。超密等离子体片在赝流光CIR暴中较弱，电子辐射带的脱落较弱。伪流光CIR风暴和头盔流光CIR风暴往往是相同的强度，如Kp，MBI（午夜边界指数）或Dst的大小测量。
A corotating interaction region (CIR) is formed when fast coronal hole origin solar wind overtakes slow solar wind and forms a region of compressed plasma and magnetic field. The slow wind upstream of the coronal hole fast wind can be either of helmet streamer origin or pseudostreamer origin. For a collection of 125 CIR‐driven geomagnetic storms, the slow wind ahead of each CIR is examined; for those storm not containing ejecta, each CIR is categorized as a helmet streamer CIR (74 of the 125 storms) or a pseudostreamer CIR (11 of the 125 storms). Separate superposed epoch studies are performed on the two groups to discern the differences between storms driven by pseudostreamer CIRs and those driven by helmet streamer CIRs. A major difference is that pseudostreamer CIR storms tend not to have a calm before the storm, so the outer plasmasphere does not refill before storm onset, and the outer electron radiation belt does not exhibit a pre‐storm decay. The superdense plasma sheet is weaker for pseudostreamer CIR storms, and the dropout of the electron radiation belt is weaker. Pseudostreamer CIR storms and helmet streamer CIR storms tend to be of the same strength as measured by the magnitude of Kp, MBI (midnight boundary index), or Dst.