Abstract

The behavior of geomagnetic disturbances during a moderate CIR storm, the most intense magnetic storm of 2009 in the solar activity minimum are considered. It is found that the substorm activity during the main phase of the storm was observed not in the nighttime but in the morning sector (0700–0900 MLT) of auroral geomagnetic latitudes (65°–67°) and was accompanied by extremely large (up to 1000 nT) geomagnetic pulsations of the Рс5 range, evidently of a non-resonant nature; the amplitude of the Y component of waves considerably exceeded that of the Х component. In the recovery phase of the magnetic storm, the tangential discontinuity in the IMF caused a substorm observed near the polar boundary of the auroral oval in the global scale in the longitude, from the evening sector to midday hours. In the daytime sector, the magnetic bay was observed several minutes later than in the nighttime sector and rapidly moved to the pole, which can be interpreted as the motion to the pole of the boundary between closed and open geomagnetic field lines and contraction of the auroral oval.

中文翻译：

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2009年7月22日的电磁风暴中高纬度地磁干扰的演变

摘要

考虑了中度CIR风暴期间的地磁干扰行为，这是2009年太阳活动最小的最强烈的磁暴。发现在风暴的主要阶段，亚暴活动不是在夜间观察到的，而是在极光地磁纬度（65°-67°）的早晨部分（0700-0900 MLT），并且伴随着极大的（向上至1000 nT）Рс5范围的地磁脉动，显然具有非共振特性；波的Y分量的幅度大大超过了Х的幅度零件。在磁暴的恢复阶段，IMF的切向不连续性引起了从晚上到午夜在经度范围内在全球范围内在极光椭圆的极边界附近观察到的亚暴。在白天，比夜间晚了几分钟才观察到磁海湾，并迅速移向极点，这可以解释为封闭和开放地磁场线之间边界向极点的运动以及极光的收缩。椭圆。