SAPS intensification during substorm recovery: A multi‐instrument case study
SAPS intensification during substorm recovery: A multi‐instrument case study
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DOI：
10.1029/2011ja016916
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发表时间：
2011-11
影响因子：
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通讯作者：
R. Makarevich;A. Kellerman;J. Devlin;H. Ye;L. Lyons;Y. Nishimura
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文献类型：
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作者：
R. Makarevich;A. Kellerman;J. Devlin;H. Ye;L. Lyons;Y. Nishimura
[1]本文介绍了在亚暴恢复阶段亚极光偏振流（SAPS）主要增强的一个事例。用Unwin高频雷达对亚极光区和极光区进行了连续的高时间分辨率多普勒速度测量，并结合IMAGE和全球定位系统卫星对极光光度和总电子含量的同时和一致测量对这些测量进行了分析。其他SuperDARN雷达、穿越充分发展的SAPS区域的DMSP F15卫星、亚暴开始位置附近的地面测量以及内磁层的GOES和LANL卫星提供了更多信息。SAPS和TEC槽之间的关联得到进一步证实，在短时间尺度和TEC显示出两种不同类型的响应亚暴爆发极和内SAPS，没有证据表明TEC减少在SAPS强化。有人认为，电场和电子密度之间的正反馈可能是不负责所观察到的SAPS增强。此外，有人提出，强烈和稳定的等离子体加速内SAPS可能触发的极光活动的爆发，而不是伴随着类似的稳定变化，在其他观测参数无论是在电离层或内磁层。也有人认为，在恢复阶段发生的SAPS加剧不一定是预期从目前的模型的SAPS的形成和演变，但与观测为基础的观点，一个完全发达的SAPS作为亚暴恢复现象是一致的。
[1] A case of the major intensification of the subauroral polarization stream (SAPS) during the substorm recovery phase is presented. The continuous high-time-resolution Doppler velocity measurements in the subauroral and auroral regions were conducted with the Unwin HF radar, and these are analyzed in the context of the simultaneous and coincident measurements of the auroral luminosity and the total electron content (TEC) by the IMAGE and GPS satellites. Additional information was provided by other SuperDARN radars, DMSP F15 satellite crossing the fully-developed SAPS region, ground-based measurements near the location of the substorm onset, and GOES and LANL satellites in the inner magnetosphere. The association between the SAPS and TEC trough is further substantiated at short timescales and TEC is shown to exhibit two distinct types of responses to substorm onset poleward of and within SAPS, with no evidence of a TEC decrease during SAPS intensification. It is argued that the positive feedback between the electric fields and electron densities was probably not responsible for the observed SAPS intensification. Moreover, it is proposed that the strong and steady plasma acceleration within SAPS may be triggered by a burst of auroral activity, rather than accompanied by a similarly steady variation in other observed parameters either in the ionosphere or in the inner magnetosphere. It is also argued that the SAPS intensification occurring during the recovery phase is not necessarily expected from the current models of the SAPS formation and evolution, but is consistent with the observationally-based view of a fully-developed SAPS as a substorm recovery phenomenon.