Generation of 100‐year geomagnetically induced current scenarios
Generation of 100‐year geomagnetically induced current scenarios
复制标题
DOI：
10.1029/2011sw000750
复制
发表时间：
2012-04
期刊：
影响因子：
--
通讯作者：
Antti Pulkkinen;E. Bernabeu;Jan Eichner;C. Beggan;A. Thomson
中科院分区：
文献类型：
--
作者：
Antti Pulkkinen;E. Bernabeu;Jan Eichner;C. Beggan;A. Thomson
考虑到与地磁感应过程相关的关键地球物理因素，探讨了一系列100年极端地电场和地磁感应电流（GIC）情景。更具体地说，我们推导出明确的地电场时间剖面，作为地面电导率结构和地磁纬度的函数。我们还演示了如何将极端地电场场景映射到GIC中。生成的统计数据表明，在导电不良和导电良好的地面结构高纬度地区，100年最大10秒地电场振幅分别为20 V/km和5 V/km。我们表明，有迹象表明，地电场震级可能在地磁纬度约40°-60°的边界处经历急剧下降。我们认为这是地磁纬度50°左右的一个阈值。亚阈值地电场强度大约比超阈值地磁纬度的地电场强度小一个数量级。需要进一步的分析来确认可能的纬度阈值的存在和位置。计算的极端GIC情景可用于进一步的工程分析，这些分析需要量化地磁风暴对导体系统（如高压输电系统）的影响。为了便于进一步开展这一专题的工作，已公开提供生成地电场情景的数字数据。
A series of 100‐year extreme geoelectric field and geomagnetically induced current (GIC) scenarios are explored by taking into account the key geophysical factors associated with the geomagnetic induction process. More specifically, we derive explicit geoelectric field temporal profiles as a function of ground conductivity structures and geomagnetic latitudes. We also demonstrate how the extreme geoelectric field scenarios can be mapped into GIC. Generated statistics indicate 20 V/km and 5 V/km 100‐year maximum 10‐s geoelectric field amplitudes at high‐latitude locations with poorly conducting and well‐conducting ground structures, respectively. We show that there is an indication that geoelectric field magnitudes may experience a dramatic drop across a boundary at about 40°–60° of geomagnetic latitude. We identify this as a threshold at about 50° of geomagnetic latitude. The sub‐threshold geoelectric field magnitudes are about an order of magnitude smaller than those at super‐threshold geomagnetic latitudes. Further analyses are required to confirm the existence and location of the possible latitude threshold. The computed extreme GIC scenarios can be used in further engineering analyses that are needed to quantify the geomagnetic storm impact on conductor systems such as high‐voltage power transmission systems. To facilitate further work on the topic, the digital data for generated geoelectric field scenarios are made publicly available.