Extended study of extreme geoelectric field event scenarios for geomagnetically induced current applications
Extended study of extreme geoelectric field event scenarios for geomagnetically induced current applications
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DOI：
10.1002/swe.20021
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发表时间：
2013-03-01
影响因子：
3.7
通讯作者：
Crowley, Geoffrey
中科院分区：
文献类型：
--
作者：
Ngwira, Chigomezyo M.;Pulkkinen, Antti;Crowley, Geoffrey
在人造地面技术系统中流动的地磁感应电流(GIC)是不利空间天气的直接表现。今天，极端空间天气事件可能对电力传输网络造成的地磁感应电流效应引起了极大的关注。由于严重社会后果的威胁，最近人们对极端地磁风暴对高压输电系统的影响产生了更大的兴趣。因此，极端地磁事件的特征对于量化极端空间天气的技术影响和社会后果至关重要。本文报道了严重/极端地磁事件期间水平地磁场的全球行为和诱发的地电场波动。这包括(1)纬度阈值边界的调查，(2)最大感应地电场的当地时间依赖性，以及(3)赤道电喷流(EEJ)电流对赤道附近地面站上方增强感应地电场发生的影响。利用地面和卫星防御气象卫星计划的测量，证实了纬度阈值边界与极光椭圆和相应的极光电喷流系统的运动有关，这是高纬度地面地磁场最大扰动的主要驱动因素。此外，我们还表明，EEJ的增强是由高纬度电场的穿透驱动的，并且EEJ带内站点的感应地电场可以比带外站点的感应地电场大一个数量级。这对位于电喷流带周围的电力网络具有重要意义，并证实了Pulkkinen等人早先的观测结果。(2012)不是孤立的事件，而是在某些严重的地磁风暴事件期间可能发生的案例。引文：Ngwira，C.M.，A.Pulkkinen，F.D.Wilder和G.Crowley(2013年)，地磁诱导电流应用的极端地电场事件场景的扩展研究，空间天气，第11期，第121-131页，DOI：10.1002/Swe.20021。
Geomagnetically induced currents (GIC) flowing in man-made ground technological systems are a direct manifestation of adverse space weather. Today, there is great concern over possible geomagnetically induced current effects on power transmission networks that can result from extreme space weather events. The threat of severe societal consequences has accelerated recent interest in extreme geomagnetic storm impacts on high-voltage power transmission systems. As a result, extreme geomagnetic event characterization is of fundamental importance for quantifying the technological impacts and societal consequences of extreme space weather. This article reports on the global behavior of the horizontal geomagnetic field and the induced geoelectric field fluctuations during severe/extreme geomagnetic events. This includes (1) an investigation of the latitude threshold boundary, (2) the local time dependency of the maximum induced geoelectric field, and (3) the influence of the equatorial electrojet (EEJ) current on the occurrence of enhanced induced geoelectric fields over ground stations located near the dip equator. Using ground-based and satellite-borne Defense Meteorological Satellite Program measurements, this article confirms that the latitude threshold boundary is associated with the movements of the auroral oval and the corresponding auroral electrojet current system, which is the main driver of the largest perturbations of the ground geomagnetic field at high latitudes. In addition, we show that the enhancement of the EEJ is driven by the penetration of high-latitude electric fields and that the induced geoelectric fields at stations within the EEJ belt can be an order of magnitude larger than that at stations outside the belt. This has important implications for power networks located around the electrojet belt and confirms that earlier observations by Pulkkinen et al. (2012) were not isolated incidences but rather cases that can occur during certain severe geomagnetic storm events. Citation: Ngwira, C. M., A. Pulkkinen, F. D. Wilder, and G. Crowley (2013), Extended study of extreme geoelectric field event scenarios for geomagnetically induced current applications, Space Weather, 11, 121-131, doi:10.1002/swe.20021.