Pi2 magnetic pulsations as response on spatio‐temporal oscillations of auroral arc current system
Pi2 magnetic pulsations as response on spatio‐temporal oscillations of auroral arc current system
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DOI：
10.1029/2000gl000037
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发表时间：
2000-07
影响因子：
5.2
通讯作者：
S. Solovyev;D. Baishev;E. Barkova;N. E. Molochushkin;K. Yumoto
中科院分区：
文献类型：
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作者：
S. Solovyev;D. Baishev;E. Barkova;N. E. Molochushkin;K. Yumoto
在磁层亚暴开始和伪暴期间，在40-150 S周期内的Pi2磁脉动都被激发。本文利用190-210°MM的观测资料，研究了短期(∼5-10分钟)活动期间，高纬Pi2脉动特征与变亮极光弧内50-200公里尺度的波状和涡旋结构参数之间的联系。我们发现，在极光弧所在的同一纬度上观测到了最大的Pi2振幅。发现高纬度Pi2脉动的周期与光度波长与其传播速度的比值一致，和/或与光度亮点的寿命一致。Pi2偏振图案由光度亮点旋转的方向定义。这些发现表明，高纬度Pi2脉动是极光弧流系统时空振荡的响应。
Pi2 magnetic pulsations in the period range from 40 to 150 s are excited both at the magnetospheric substorm onset and during pseudobreakups. Using observations at the 190–210° MM we study the association between the characteristics of high‐latitude Pi2 pulsations and parameters of wave‐like and vortex auroral structures of 50–200 km scale in the brightening auroral arc during short‐term (∼5–10 min) activations. We found that the maximum Pi2 amplitude is observed at the same latitude where the auroral arc is located. The period of high‐latitude Pi2 pulsations is found to be consistent with the ratio of the luminosity wavelength to their propagation velocity and/or coincides with the lifetime of luminosity bright spots. The Pi2 polarization patterns are defined by the direction of luminosity bright spot rotation. These findings indicate that high‐latitude Pi2 pulsations are the response of spatio‐temporal current system oscillations of the auroral arc.