Modelling the impact of geomagnetically induced currents on UK railways

模拟地磁感应电流对英国铁路的影响

• 批准号: NE/Y001176/1
• 负责人: Ciaran Beggan
• 金额: $ 26.72万
• 依托单位: British Geological Survey
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2024
• 资助国家: 英国
• 起止时间: 2024 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FY001176%2F1
• 关键词: Modelling; impact; geomagnetically; induced; currents

Space weather encompasses a range of environmental phenomena, ultimately driven by solar activity. The emission of solar energy and material directed towards Earth can drive electromagnetic disturbances at the planet's surface. Under normal levels of solar activity, the impact of space weather is minimal. However, natural variations in solar activity can drive periods of severe (typically on decadal timescales) and extreme (once every few hundred years) space weather during which the intensity of these phenomena can increase by many orders of magnitude. Rapid, high-amplitude geomagnetic variations during space weather storms induce geoelectric fields in the electrically conductive subsurface of the Earth. The imbalance in the geoelectric field between different regions causes Geomagnetically Induced Currents (GIC) to flow in conducting structures grounded to the Earth. Space weather thus presents an environmental risk to some of the critical hardware, infrastructure and services underpinning our society and economy. The risk of space weather is recognised by its inclusion in the UK National Risk Register for Civil Emergencies.Railways were among the first modern infrastructure to be impacted by space weather due their reliance on telegraph technology for signalling purposes. It was reported in an 1871 issue of Nature that the interference due to a geomagnetic storm delayed trains in Exeter, and the astronomer Walter Maunder, reported interference with railway signalling equipment during the geomagnetic storm of November 1882. The storm of May 1921 had such an extensive impact on the operation on railway operations in New York State that it has been dubbed the "New York Railroad storm". Modern signalling has moved away from telegraph-based systems, but contemporary technologies are not immune from GIC. Track circuits are one of the main systems used to detect trains along a section of railway line and prevent other train from entering that section. They rely upon an electrical circuit in which the train's axles close a current loop between the rails but are vulnerable to interference from stray currents induced in the rails. There is recent evidence of anomalies in such signalling systems that coincided with the occurrence of geomagnetic-storm conditions in Swedish and Russian rail operations. Signalling systems reported false blockages (right-side failure) in sectors where no trains were present and statistical analyses of anomaly data indicate that the occurrence and duration of these anomalies showed a 5-7 times higher probability of occurrence during strong geomagnetic storms. These impacts may not be limited to infrastructure at high latitudes. Indeed, there is an increasing awareness from parallel research to understand the risks posed to electricity transmission grids that the GIC risk is a threat to mid- and low-latitude regions since severe and extreme space weather events push geomagnetic disturbance equatorwards. However, the risks to rail systems remain uncertain. For example, it is unclear how likely GIC are to induce wrong-side (i.e. safety critical) failures in such systems and we have yet to experience the impact of a reasonable worst-case scenario, such as the 1859 superstorm known as the "Carrington Event", on modern rail systems.In this project, we shall undertake experimental and modelling work to comprehensively explore the space weather risk to rail signalling for the first time. This will include measurements that will enable us to assess the geoelectric field imposed upon the ground in the UK under any observed geomagnetic conditions. We will also build a state-of-the-art computer model of the rail network in the UK that will enable us to evaluate (i) the geomagnetic environmental factors and (ii) the characteristics of the network relevant to signalling misoperations. The results will be important for other space weather researchers, rail operators and policy makers.

太空天气包括一系列环境现象，最终由太阳能活动驱动。朝向地球的太阳能和材料的发射可以驱动地球表面的电磁干扰。在正常的太阳活动水平下，太空天气的影响很小。但是，太阳能活动的自然变化可能会驱动严重的（通常在十年时间尺度上）和极端（每几百年一次）的太空天气，在此期间，这些现象的强度可以增加许多数量级。太空天气风暴期间的快速，高振幅的地磁变化诱导地球的导电地下地球场。不同区域之间地球电场的不平衡导致地球诱导的电流（GIC）在接地地接地的结构中流动。因此，太空天气给一些关键的硬件，基础设施和服务带来了环境风险，为我们的社会和经济带来了影响。太空天气的风险因其纳入英国国家海报风险登记登记册而认识到。瑞道是最早受到太空天气影响的现代基础设施之一，因为它们依靠电报技术来发动信号。据报道，在1871年的《自然》中报道说，由于地貌风暴引起的干扰延迟了埃克塞特的火车，天文学家沃尔特·莫德（Walter Maunder）报告说，在1882年11月的地磁风暴中干扰了铁路信号设备。现代信号已从基于电报的系统中移开，但是当代技术并不能免于GIC。轨道电路是用于检测沿铁路线的火车的主要系统之一，并防止其他火车进入该部分。他们依靠电路，在该电路中，火车的车轴在轨道之间关闭电流环，但很容易受到导轨中引起的流浪电流的干扰。最近有证据表明，这种信号传导系统中的异常情况与瑞典和俄罗斯铁路运营中的地磁态度的发生相吻合。信号系统报告在没有火车的部门中报告了错误的堵塞（右侧故障），并且对异常数据的统计分析表明，这些异常的发生和持续时间显示出强烈地磁风暴期间发生发生的5-7倍。这些影响可能不仅限于高纬度的基础设施。确实，从平行研究中，人们的意识越来越多，以了解电力传输网格的风险，即GIC风险是对中和低纬度地区的威胁，因为严重和极端的太空天气事件推动了地磁干扰赤道。但是，铁路系统的风险仍然不确定。例如，目前尚不清楚GIC在此类系统中诱导错误侧（即安全性的严重）失败的可能性，我们尚未体验到合理的最坏情况的影响，例如1859年的1859年超级风暴，称为“ Carrington事件”，“ Carrington事件”，对现代铁路系统。在这个项目中，我们应对实验和建模的范围进行大量探索，以探索型号的速度，以探索最初的风险。这将包括测量值，使我们能够在任何观察到的地磁条件下评估英国施加的地面地球场。我们还将在英国建立一个最先进的电脑网络计算机模型，使我们能够评估（i）（i）地磁环境因素以及（ii）与信号误传有关的网络特征。结果对于其他太空天气研究人员，铁路运营商和政策制定者将很重要。