Investigating the Drivers of Geomagnetically Induced Currents

研究地磁感应电流的驱动因素

基本信息

批准号：
NE/W006766/1
负责人：
Suzanne Imber
金额：
$ 53.23万
依托单位：
University of Leicester
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2023
资助国家：
英国
起止时间：
2023 至无数据
项目状态：
未结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FW006766%2F1
关键词：
Investigating Drivers Geomagnetically Induced Currents

项目摘要

The Earth's magnetic field sits within the changeable, dynamic environment of the solar wind. The interaction of the two regimes drives rapid reconfigurations of the Earth's field, which induce currents to flow in conductors on the ground. These Geomagnetically Induced Currents (GICs) can be 10s to 100s of Amps, and can cause transformer heating and higher harmonics in power grids, degradation to metal pipelines, and signalling malfunctions on railway systems. The Lloyd's of London 2013 Space Weather report concluded that a once-in-a-Century event 'would cause major disruption to transport, food supplies, emergency and hospital services amongst other things...The absence of such fundamental services could lead to major and widespread social unrest, riots and theft with ramifications for the insurance industry and society in general'. The cost of such an event to the UK has been estimated at £0.9-15.9 billion, and while such huge events are rare, smaller, damaging, events are routinely observed.The key to predicting the location and magnitude of GICs is understanding the chain of causality from the Sun to the Earth's surface, and having instrumentation in key locations to make the measurements required for forecasting. Typical solar wind structures that drive powerful GICs have been identified, and can provide some early warning of extreme dynamics in the Earth's system. The other end of the chain, inducing currents in conductors on the ground due to a variable magnetic field, may be addressed through the application of Faraday's Law, given the conductivity of the local regolith, and the conductivity, length and orientation of the conductor. Typically, this research is funded by individual nations focussing on operational risk to their own critical infrastructure, and therefore the global picture is less well understood. The missing link required for accurate GIC forecasting is the physics of the central part of the chain: understanding how the highly dynamic ionospheric current systems generate the geomagnetic disturbances that drive GICs measured in infrastructure, thus enabling the coupling of existing solar wind/magnetosphere models with ground-based conductivity maps.We will use data from ground-based magnetometers (>200 stations) spread across every continent, to determine the location, timing and intensity of all geomagnetic disturbances over an eight-year period (2010-2017). These signatures will be related to their ionospheric drivers using a constellation of 66 satellites in low-Earth orbit which provide continual 2-minute snapshots of the magnetic energy stored in the system during this time period, and accurately characterise the location, direction and magnitude of the ionospheric current systems. The novelty of this approach is combining these two data sets for the first time to allow a global, statistical analysis over an entire solar maximum period.We will largely focus on high latitude regions (including northern Europe, Canada and the northern United States) where the most intense GICs are observed. Our work is relevant to space weather service providers (such as the UK Met Office), the energy and rail industries, and governments who monitor risk to critical infrastructure, as well as for future infrastructure planning. We will also study equatorial and mid-latitude disturbances, as these have the potential to disrupt infrastructure supporting major population centres, and the combination of equatorial and higher-latitude events could be highly damaging to infrastructure on a continental scale (such as in South America). This work will be a pathfinder for the feasibility of nowcasting, and perhaps even forecasting, of GICs, using acombination of existing satellite networks and solar wind monitors.

地球磁场位于太阳风的多变动态环境中，这两种状态的相互作用驱动地球磁场的快速重新配置，从而在地面导体中感应出电流。数十至数百安培，可能导致变压器发热和电网中的高次谐波、金属管道退化以及铁路系统信号故障。伦敦劳合社 2013 年太空天气报告得出的结论是，百年一遇的事件“将对交通、食品供应、紧急情况和医院服务等造成重大干扰……缺乏此类基础服务可能会导致重大和据估计，此类事件给英国造成的损失为 0.9 至 159 亿英镑，虽然此类重大事件很少见，规模较小，破坏性也很大。预测 GIC 的位置和强度的关键是了解从太阳到地球表面的因果链，并在关键位置安装仪器来进行预测所需的典型太阳风结构。 GIC 已被识别，并且可以对地球系统中的极端动态提供一些早期预警。链的另一端，由于可变磁场而在地面导体中感应电流，可以通过应用来解决。法拉第定律，考虑到当地风化层的电导率以及导体的电导率、长度和方向，通常，这项研究由各个国家资助，重点关注其自己的关键基础设施的运营风险，因此全球情况不太了解。准确的 GIC 预测所需的缺失环节是该链中心部分的物理原理：了解高度动态的电离层电流系统如何产生驱动基础设施中测量的 GIC 的地磁扰动，从而实现现有太阳能的耦合。风/磁层模型与地面电导率图。我们将使用分布在各大洲的地面磁力计（> 200 个站点）的数据来确定八年期间（2010 年）所有地磁扰动的位置、时间和强度-2017）。这些特征将与其使用低地球轨道上的 66 颗卫星组成的星座的电离层驱动器相关，这些卫星提供连续的 2 分钟磁能快照。该方法的新颖之处在于首次将这两个数据集结合起来，以便对整个太阳系进行全局统计分析。我们将主要关注观测到最强烈 GIC 的高纬度地区（包括北欧、加拿大和美国北部），我们的工作与空间天气服务提供商（例如英国气象局）相关。能源和铁路行业以及监控风险的政府我们还将研究赤道和中纬度扰动，因为这些扰动有可能破坏支持主要人口中心的基础设施，而赤道和高纬度事件的结合可能会造成巨大破坏。这项工作将成为利用现有卫星网络和太阳风监测器进行临近预报甚至预测的可行性的探路者。