Ground geomagnetic field and GIC response to March 17, 2015, storm
Ground geomagnetic field and GIC response to March 17, 2015, storm
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2015 年 3 月 17 日风暴的地面地磁场和 GIC 响应
DOI：
10.1186/s40623-018-0933-2
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
Y. Sakharov
中科院分区：
文献类型：
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作者：
O. Kozyreva;V. Pilipenko;V. Belakhovsky;Y. Sakharov
2015年3月17日的圣帕特里克日磁暴被空间界选择进行协同分析，以建立更全面的风暴起源和演变情况。这场风暴有一个异常长的主相（约17小时）。在此期间，发生了许多类似亚暴的激活。这些激活导致科拉半岛电力线中地磁感应电流（GIC）的爆发。为了更详细地研究亚暴激活，我们应用各种数据处理技术的全球范围内的磁强计阵列：虚拟磁图，磁纬度当地时间（MLT）快照，磁keograms。这些技术都是简单的工具，是对为分析SuperDARN、IMAGE和CARISMA阵列而开发的更先进设施的补充。我们比较了全球空间定位和时间演化的地磁X分量扰动和磁场变化测量的希尔伯特变换的时间导数dB/dt。这些震级的纬度-MLT映射显示，通常具有最高磁变的区域不会与亚暴“震中”重叠，而是向其极向或赤道向边界移动。地磁场的最高可变性以及由此产生的强烈GIC是由中等尺度的快速变化结构引起的。亚暴强度与GIC震级之间不存在一一对应关系。
The St. Patrick’s Day geomagnetic storm on March 17, 2015, has been chosen by the space community for synergetic analysis to build a more comprehensive picture of the storm’s origin and evolution. This storm had an unusually long (~ 17 h) main phase. During this period, many substorm-like activations occurred. These activations resulted in bursts of geomagnetically induced currents (GICs) in power lines on the Kola peninsula. To examine the substorm activations in more detail, we apply various data processing techniques for the world-wide array of magnetometers: the virtual magnetograms, magnetic latitude–local time (MLT) snapshots, and magnetic keograms. These techniques are simple tools that are supplementary to more advanced facilities developed for the analysis of SuperDARN, IMAGE, and CARISMA arrays. We compare the global spatial localization and time evolution of the geomagnetic X-component disturbance and magnetic field variability measured by the Hilbert transform of time derivative dB/dt. The latitude-MLT mapping of these magnitudes shows that very often a region with highest magnetic variability does not overlap with a substorm “epicenter” but is shifted to its poleward or equatorward boundaries. Highest variability of the geomagnetic field, and consequently intense GICs, are caused by medium-scale fast varying structures. There is no one-to-one correspondence between substorm intensity and GIC magnitude.