EISCAT_3D: Fine-scale structuring, scintillation, and electrodynamics (FINESSE)

EISCAT_3D：精细结构、闪烁和电动力学 (FINESSE)

• 批准号: NE/W003015/1
• 负责人: Adrian Grocott
• 金额: $ 14.44万
• 依托单位: Lancaster University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FW003015%2F1
• 关键词: EISCAT_3D; Fine; scale; structuring; scintillation

The UK along with the rest of the world is becoming increasingly dependent on technological systems, including satellite communications, global positioning systems, and power grids, that are at risk from space weather. Many space weather hazards originate in the ionosphere, the ionised upper part of the atmosphere at altitudes of 90 km and above, where solar wind energy channelled by the Earth's magnetic field can cause a variety of unpredictable and deleterious effects. It causes electrical currents to flow, which heat the atmosphere in a process known as Joule heating, which in turn can cause the atmosphere to expand upwards, producing drag on satellites, hence making their orbits harder to predict and reducing their lifetimes. It produces horizontal motions of the ionosphere which modify the neutral winds in the thermosphere through friction. It produces the auroras, associated with particle precipitation from the magnetosphere above, which modify the ionospheric structure. Moreover, it gives rise to plasma instabilities which cause the ionosphere to become corrugated, scattering radio waves from satellites consequently disturbing communications and GPS. Although the large-scale distribution of such space weather hazards is relatively well reproduced in global circulation models, the physics occurring on spatial scales smaller than the model grid is poorly understood, which holds back improvements in forecasting. The FINESSE project will exploit a new and unique NERC-funded incoherent scatter radar system, EISCAT_3D, located in northern Scandinavia, to study these sub-grid space weather scales. EISCAT_3D will be able to determine the ionospheric structure in a box roughly 200 km to a side horizontally and 800 km vertically, at an unprecedented spatial and temporal resolution, to image the processes leading to space weather effects. FINESSE will also exploit a next-generation coherent scatter radar to measure ionospheric motions, three neutral wind imagers to measure the interaction between the thermosphere and the ionosphere, three all-sky auroral cameras to view regions of precipitation from the magnetosphere above, a fine-scale auroral imager to observe auroral structures on spatial and temporal scales even finer than EISCAT_3D can probe, and a radio telescope and network of GPS receivers to look at the scintillation of radio signals from both cosmic sources and satellites. The main aims of FINESSE are as follows. 1) To determine the small-scale sources of Joule heating, to place these within the context of the larger picture of polar auroral disturbances, to determine the link between Joule heating and satellite drag, and to incorporate these results to improve forecast models. 2) To determine the cause of small-scale ionospheric structuring, and to understand how this leads to scintillation of radio signals. 3) To probe auroral dynamics at the very smallest temporal and spatial scales to understand the physics of coupling between the magnetosphere and ionosphere, the role auroral processes play in heating and structuring the ionosphere and atmosphere, and the instability that leads to substorms (explosive releases of energy into the nightside auroral ionosphere). FINESSE will liaise with space weather forecasters and other stakeholders to disseminate this greater understanding of small-scale processes in producing space weather hazards and to translate it into significant economic benefit to the UK.

英国和世界其他国家越来越依赖技术系统，包括卫星通信、全球定位系统和电网，而这些系统面临着太空天气的风险。许多太空天气危害源自电离层，即海拔 90 公里及以上的电离大气层上部，地球磁场引导的太阳风能量可能会造成各种不可预测的有害影响。它会导致电流流动，从而在焦耳加热过程中加热大气，进而导致大气向上膨胀，对卫星产生阻力，从而使卫星的轨道更难预测并缩短其寿命。它产生电离层的水平运动，通过摩擦改变热层中的中性风。它产生极光，与上方磁层的粒子降水有关，从而改变电离层结构。此外，它还会引起等离子体不稳定，导致电离层出现波纹，散射来自卫星的无线电波，从而干扰通信和全球定位系统。尽管在全球环流模型中相对较好地再现了此类空间天气灾害的大规模分布，但对小于模型网格的空间尺度上发生的物理现象了解甚少，这阻碍了预测的改进。 FINESSE 项目将利用 NERC 资助的新型独特非相干散射雷达系统 EISCAT_3D（位于斯堪的纳维亚半岛北部）来研究这些子网格空间天气尺度。 EISCAT_3D 将能够以前所未有的空间和时间分辨率确定一个水平方向大约 200 公里、垂直方向大约 800 公里的盒子中的电离层结构，以对导致空间天气效应的过程进行成像。 FINESSE还将利用下一代相干散射雷达来测量电离层运动，三个中性风成像仪来测量热层和电离层之间的相互作用，三个全天极光相机来观察上方磁层的降水区域，一个精细-尺度极光成像仪在空间和时间尺度上观察极光结构，甚至比 EISCAT_3D 所能探测到的更精细，并使用射电望远镜和 GPS 接收器网络来观察极光的闪烁来自宇宙源和卫星的无线电信号。 FINESSE 的主要目标如下。 1) 确定焦耳热的小规模来源，将其置于极地极光扰动的大背景中，确定焦耳热和卫星阻力之间的联系，并将这些结果纳入改进预报模型。 2) 确定小规模电离层结构的原因，并了解其如何导致无线电信号闪烁。 3) 在最小的时间和空间尺度上探测极光动力学，以了解磁层和电离层之间耦合的物理原理、极光过程在加热和构建电离层和大气中所起的作用，以及导致亚暴（爆炸性释放）的不稳定性能量进入夜间极光电离层）。 FINESSE 将与太空天气预报员和其他利益相关者联络，以传播对产生太空天气灾害的小规模过程的更深入的了解，并将其转化为英国的重大经济效益。