Modeling Geoelectric Fields in Ireland and the UK for Space Weather Applications
Modeling Geoelectric Fields in Ireland and the UK for Space Weather Applications
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DOI：
10.1029/2018sw001999
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发表时间：
2019-02
期刊：
影响因子：
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通讯作者：
J. Campanyà;P. Gallagher;S. Blake;M. Gibbs;D. Jackson;C. Beggan;G. Richardson;C. Hogg
中科院分区：
文献类型：
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作者：
J. Campanyà;P. Gallagher;S. Blake;M. Gibbs;D. Jackson;C. Beggan;G. Richardson;C. Hogg
由磁暴引起的地球表面的地电场有可能破坏和损坏地面基础设施，如配电网络，管道和铁路。在这里，我们模拟地电场在爱尔兰和英国在安静和活跃的时间间隔的地磁条件下使用测量从磁观测站和电磁张量的关系。分析的重点是：（1）确定受磁暴影响较大的磁场变化周期，在30到30，000 s之间;（2）限制定义地球对磁场变化响应的电磁张量关系;（三）实施和验证两种方法，用于基于来自磁观测站和本地和站间电磁传递函数;（4）估计地电场建模时的不确定性。使用站间张量关系使我们能够区分区域和当地的地磁源。我们发现相干值为0.5-0.95，信噪比为1-15 dB，归一化均方根值为0.8-3.4，均方根值为0.7-84 mV/km。在这些数值范围内，距离地磁观测站很近（<100公里）且不受当地风暴影响的站点将提供最准确的结果，而距离较远且受风暴空间局部特征影响的站点将不太准确。这些方法使我们能够更准确地模拟地磁感应电流，及其相关的不确定性，在英国和爱尔兰的电力网络。
Geoelectric fields at the Earth's surface caused by geomagnetic storms have the potential to disrupt and damage ground‐based infrastructure such as electrical power distribution networks, pipelines, and railways. Here we model geoelectric fields in Ireland and the UK during both quiet and active time intervals of geomagnetic conditions using measurements from magnetic observatories and electromagnetic tensor relationships. The analysis focused on (1) defining periods of the magnetic field variations that are largely affected by the geomagnetic storms, between 30 and 30,000 s; (2) constraining the electromagnetic tensor relationships that defines the Earth's response to magnetic field variations; (3) implementing and validating two approaches for modeling geoelectric fields based on measurements from magnetic observatories and local and interstation electromagnetic transfer functions; and (4) estimating uncertainties when modeling geoelectric fields. The use of interstation tensor relationships allowed us to differentiate between regional and local geomagnetic sources. We found coherence values of 0.5–0.95, signal‐to‐noise ratio of 1–15 dB, normalized root‐mean‐square values of 0.8–3.4, and root‐mean‐square values of 0.7–84 mV/km. Within these ranges of values, sites in close proximity (<100 km) to a magnetic observatory and not affected by local storms will provide the most accurate results, while sites located at further distances and affected by spatially localized features of the storm will be less accurate. These methods enable us to more accurately model geomagnetically induced currents, and their associated uncertainties, in the British and Irish power networks.