DETERMINING AND PREDICTING THE SIZE AND ONSET TIMES OF SUBSTORMS

确定和预测亚风暴的规模和爆发时间

• 批准号: NE/N014480/1
• 负责人: Colin Forsyth
• 金额: $ 61.32万
• 依托单位: University College London
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FN014480%2F1
• 关键词: DETERMINING; PREDICTING; SIZE; ONSET; TIMES

The Sun's influence on the Earth goes well beyond gravitational attraction and shiny light and heat down on the Earth's surface; the Sun and Earth are connected by a stream of charged particles that is constantly flowing off the Sun and becoming trapped in the Earth's magnetic field. These charged particles bring with them the Sun's magnetic field, which can join up with the Earth's field, causing those trapped charged particles to become energised and to fly along the Earth's magnetic field into the atmosphere. When these particles hit the atmosphere, they cause it to glow in spectacular light displays that we call the aurora. The Earth is protected from most of the particles coming off the Sun by its magnetic field. As it expands out into space, it is deformed by the charged particles flowing off the Sun impacting upon it. It forms a bullet-like shaped region extending 60,000 km in front of the Earth, and over 600,000 km behind the Earth and known as the magnetosphere. As the solar particles and magnetic field hit the magnetosphere, it absorbs energy, storing that energy in the magnetic field behind the Earth. This store of energy is unstable, and eventually it is released, energising charged particles in the magnetosphere to create bright aurora in a process known as a substorm. These substorms happen three to four times per day, lighting up the night sky in the northern and southern polar regions for hours on end. To an observer in the right place on the ground, the whole of the night sky will light up over half-an-hour, before slowly fading for another hour or so.Whilst displays of substorm aurora are stunningly beautiful, they are far from benign. The particles associated with them can drive extremely large currents through the atmosphere that can cause other currents to flow on the ground. These currents can cause damage to electrical equipment and power networks, potentially leading to blackouts across large swathes of the Earth's surface. The energisation of charged particles in space can be hazardous to spacecraft, potentially causing millions of pounds worth of damage in a matter of seconds. As such, in a world that is increasingly reliant on space-based and electrical technology, these substorms represent a very real risk. Scientists also believe that these events can cause changes in the upper atmosphere that can affect its chemistry and potentially impact on climate, but as yet this effect is poorly understood owing to a lack of necessary observations.Despite being known about for thousands of years and studied in detail since the turn of the last century, we still are unable to accurately predict when and where these space weather events will occur. This is a major hurdle in space weather science that has remained a problem in this field due to a combination of lack of data and lack of the necessary tools to properly analyse this data. However, we are now in the best position to date to address these issues. The new research proposed in this project will combine datasets that have been collected over the last 20 years and answer the questions "when will these events occur?", "what will their impact be?" and "what controls them?". By answering these questions, we will be able to understand what we need to know in order to predict when these events will occur and what there impact will be.

太阳对地球的影响远远超出了地球表面的万有引力和闪亮的光和热;太阳和地球由一股不断从太阳流出并被困在地球磁场中的带电粒子流连接。这些带电粒子带来了太阳的磁场，太阳的磁场可以与地球的磁场结合起来，使那些被困的带电粒子被激发，并沿着地球的磁场进入大气层。当这些粒子撞击大气层时，它们会使大气层发出壮观的光，我们称之为极光。地球受到磁场的保护，不受来自太阳的大部分粒子的影响。当它膨胀到太空中时，它会受到太阳流出的带电粒子的影响而变形，形成一个子弹状的区域，在地球前方延伸60，000公里，在地球后方延伸超过600，000公里，称为磁层。当太阳粒子和磁场撞击磁层时，它吸收能量，将能量储存在地球后面的磁场中。这种能量储存是不稳定的，最终它被释放出来，激发磁层中的带电粒子，在一个被称为亚暴的过程中产生明亮的极光。这些亚暴每天发生三到四次，连续几个小时照亮北方和南极地区的夜空。对于一个在地面上正确位置的观测者来说，整个夜空将亮起半个多小时，然后再慢慢消失一个小时左右。虽然亚暴极光的显示令人惊叹地美丽，但它们远非良性。与它们相关的粒子可以驱动非常大的电流通过大气层，从而导致其他电流在地面上流动。这些电流会对电力设备和电网造成损害，可能导致地球表面大片地区停电。太空中带电粒子的能量可能对航天器造成危险，可能在几秒钟内造成价值数百万英镑的损害。因此，在一个日益依赖天基技术和电子技术的世界中，这些亚暴是一种非常真实的风险。科学家们还认为，这些事件可能导致高层大气发生变化，从而影响其化学性质，并可能对气候产生影响，但由于缺乏必要的观测，迄今对这种影响了解甚少，尽管人们对这种影响已有数千年的了解，并自上个世纪以来对其进行了详细研究，但我们仍然无法准确预测这些空间天气事件将在何时何地发生。这是空间气象科学中的一个主要障碍，由于缺乏数据和缺乏适当分析这类数据的必要工具，空间气象科学一直是这一领域的一个问题。然而，我们现在处于迄今为止解决这些问题的最佳位置。该项目提出的新研究将联合收割机结合过去20年收集的数据集，回答“这些事件何时发生？“、“它们的影响会是什么？“和“是什么控制着它们？".通过回答这些问题，我们将能够理解我们需要知道什么，以便预测这些事件何时发生以及会产生什么影响。

项目成果

Tailward Propagation of Magnetic Energy Density Variations With Respect to Substorm Onset Times

• DOI: 10.1029/2017ja025147
• 发表时间: 2018-06
• 期刊: Journal of Geophysical Research: Space Physics
• 作者: J. Coxon;M. Freeman;C. Jackman;C. Forsyth;I. J. Rae;R. Fear

Direct Evidence of Magnetic Reconnection Onset via the Tearing Instability

通过撕裂不稳定性磁重联开始的直接证据

• DOI: 10.3389/fspas.2022.869491
• 发表时间: 2022
• 期刊: Frontiers in Astronomy and Space Sciences
• 影响因子: 3
• 作者: Bakrania M

Physical Processes of Meso-Scale, Dynamic Auroral Forms

• DOI: 10.1007/s11214-020-00665-y
• 发表时间: 2020-04
• 期刊: Space Science Reviews
• 影响因子: 10.3
• 作者: C. Forsyth;V. Sergeev;M. Henderson;Y. Nishimura;B. Gallardo‐Lacourt

Forecasting GOES 15 >2 MeV Electron Fluxes From Solar Wind Data and Geomagnetic Indices

• DOI: 10.1029/2019sw002416
• 发表时间: 2020-08
• 期刊: Space Weather
• 作者: Colin Forsyth;C. E. Watt;M. Mooney;I. J. Rae;S. Walton;R. Horne

What effect do substorms have on the content of the radiation belts?

• DOI: 10.1002/2016ja022620
• 发表时间: 2016-07
• 期刊: JOURNAL OF GEOPHYSICAL RESEARCH-SPACE PHYSICS
• 影响因子: 2.8
• 作者: Forsyth, C.;Rae, I. J.;Murphy, K. R.;Freeman, M. P.;Huang, C. -L.;Spence, H. E.;Boyd, A. J.;Coxon, J. C.;Jackman, C. M.;Kalmoni, N. M. E.;Watt, C. E. J.
• 通讯作者: Watt, C. E. J.