DETERMINING AND PREDICTING THE SIZE AND ONSET TIMES OF SUBSTORMS

太阳对地球的影响远远超出了引力和地球表面的光和热；太阳和地球是由带电粒子流连接起来的，这些粒子流不断地从太阳流出，并被困在地球的磁场中。这些带电粒子带着太阳的磁场，太阳的磁场可以与地球的磁场结合，使那些被困的带电粒子变得充满能量，并沿着地球的磁场飞向大气层。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。地球的磁场保护地球不受来自太阳的大部分粒子的伤害。当它向太空膨胀时，它会被从太阳流出的带电粒子撞击而变形。它形成了一个子弹状的区域，在地球前面延伸6万公里，在地球后面延伸60多万公里，被称为磁层。当太阳粒子和磁场撞击磁层时，它会吸收能量，并将能量储存在地球背后的磁场中。这种储存的能量是不稳定的，最终会被释放出来，激发磁层中的带电粒子，产生明亮的极光，这一过程被称为亚风暴。这些亚暴每天发生三到四次，连续数小时照亮北极和南极地区的夜空。对于地面上正确位置的观测者来说，整个夜空将在半小时内亮起来，然后再慢慢变暗一个小时左右。虽然亚风暴极光的展示是惊人的美丽，但它们远不是良性的。与它们相关的粒子可以在大气中产生极大的电流，从而导致其他电流在地面上流动。这些电流会对电气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对航天器来说是危险的，可能会在几秒钟内造成价值数百万英镑的损失。因此，在一个越来越依赖太空和电子技术的世界里，这些亚暴代表着一个非常现实的风险。科学家们还认为，这些事件会引起高层大气的变化，从而影响其化学成分，并可能对气候产生影响，但由于缺乏必要的观测，人们对这种影响知之甚少。尽管自上个世纪初以来，人们已经了解了数千年，并对其进行了详细的研究，但我们仍然无法准确预测这些太空天气事件将在何时何地发生。由于缺乏数据和缺乏适当分析这些数据的必要工具，这是空间气象科学的一个主要障碍，在这个领域仍然是一个问题。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结合过去20年收集的数据集，并回答“这些事件何时发生？”、“它们的影响是什么？”以及“是什么控制了它们？”等问题。通过回答这些问题，我们将能够了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。

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.