Geoeffectiveness of stream interaction regions during 2007–2008
Geoeffectiveness of stream interaction regions during 2007–2008
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DOI：
10.1002/2016sw001559
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发表时间：
2016-07
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影响因子：
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通讯作者：
E. Sánchez-García;E. Aguilar-Rodriguez;V. Ontiveros;J. A. Gonzalez-Esparza
中科院分区：
文献类型：
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作者：
E. Sánchez-García;E. Aguilar-Rodriguez;V. Ontiveros;J. A. Gonzalez-Esparza
当太阳风的速度快于太阳风的速度慢时，行星际介质中就会产生流相互作用区。如果这些大规模的现象与地球的磁层相互作用，它们可能会引起磁暴（GS）。它们的地球有效性是用不同纬度的磁性指数来衡量的。在这项研究中，我们分析了2007年至2008年期间由SIR产生的20个GS的地球有效性，并由ACE，Wind和STEREO‐A/B航天器进行了观测。我们比较了地磁响应SIRs磁层相互作用，采用不同的地磁指数在低，中，高纬度。使用aa、Kp和SYM-H指数的标准，地理有效性分别为50%、55%和90%。我们发现，在大多数情况下，各指标的最大强度处于弱到中等范围。根据SYM-H指数，10%、60%和10%的前向冲击分别伴随着平静、微弱和温和的GS。然而，根据Kp指数，10%和20%之后分别是轻微和中度GS。我们分析了流界面（SI）的相对位置的SIR内的地理有效区域。对于75%的GS，它们的最大强度出现在扰动的快速太阳风期间（SI通过之后），这将与SIR的效率有关。各指标达到最大强度的时间差Δt均小于36 h。
The stream interaction regions (SIRs) are generated in the interplanetary medium when a fast solar wind stream overtakes a slower one. If these large‐scale phenomena interact with the Earth's magnetosphere, they can give rise to geomagnetic storms (GSs). Their geoeffectivity is measured using magnetic indices at different latitudes. In this study we analyzed the geoeffectiveness of 20 GSs that were generated by SIRs during the period of 2007 to 2008 and observed by the ACE, Wind, and STEREO‐A/B spacecraft. We compared the geomagnetic response to the SIRs‐magnetosphere interaction employing different geomagnetic indices at low, middle, and high latitudes. The geoeffectiveness was 50%, 55%, and 90% using the criteria of the aa, Kp, and SYM‐H indices, respectively. We found that in most cases the maximum intensity of each index was in the weak to moderate range. According to the SYM‐H index, a 10%, 60%, and 10% of the forward shocks were followed by quiet, weak, and moderate GSs, respectively. The 10% and 20%, however, were followed by minor and moderate GSs, respectively, according to the Kp index. We analyzed the geoeffective region within the SIRs with respect to the relative position of the stream interface (SI). For 75% of GSs, their maximum intensity occurred during the disturbed fast solar wind (after the passing of the SI), which would be related to the efficiency of a SIR. The time difference Δt between the passing of the SI and the maximum intensity in each index was less than 36 h.