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.

英国沿着世界其他地区，越来越依赖于技术系统，包括卫星通信、全球定位系统和电网，这些系统都面临着空间天气的风险。许多空间天气危害源自电离层，即高度在90公里及以上的电离大气层上部，在那里，由地球磁场引导的太阳风能可造成各种不可预测的有害影响。它导致电流流动，在一个称为焦耳加热的过程中加热大气层，这反过来又会导致大气层向上膨胀，对卫星产生阻力，从而使其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，与来自上方磁层的粒子沉淀有关，改变了电离层结构。此外，它还引起等离子体的不稳定性，使电离层产生波纹，散射来自卫星的无线电波，从而干扰通信和全球定位系统。虽然全球环流模型较好地再现了这种空间气象灾害的大规模分布，但对在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项目将利用位于斯堪的纳维亚半岛北方的一个新的、独特的、由NERC资助的非相干散射雷达系统EISCAT_3D来研究这些次网格空间天气尺度。EISCAT_3D将能够以前所未有的空间和时间分辨率确定水平方向约200公里、垂直方向约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，利用三个中性风成像仪来测量热层和电离层之间的相互作用，利用三个全天空极光照相机来观察磁层上方的降水区域，利用一个精细比例极光成像仪来观察空间和时间尺度上的极光结构，甚至比EISCAT_3D可以探测的还要精细，还有一个射电望远镜和全球定位系统接收器网络，用于观察来自宇宙源和卫星的无线电信号的闪烁。FINESSE的主要目标如下。 1)确定焦耳加热的小规模来源，将其置于极地极光扰动的大背景下，确定焦耳加热与卫星阻力之间的联系，并将这些结果纳入改进预测模型。2)确定小尺度电离层结构的原因，并了解这是如何导致无线电信号闪烁的。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的耦合物理学、极光过程在电离层和大气层的加热和结构化方面的作用，以及导致亚暴的不稳定性（能量爆炸性释放到夜面极光电离层）。FINESSE将与空间气象预报员和其他利益攸关方联络，传播对产生空间气象灾害的小规模过程的更深入了解，并将其转化为联合王国的重大经济效益。