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/W002981/1
• 负责人: Yulia Bogdanova
• 金额: $ 27.9万
• 依托单位: Science and Technology Facilities Council
• 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%2FW002981%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一样，正变得越来越依赖技术系统，包括卫星通信、全球定位系统和电网，这些系统都面临着太空天气的风险。许多空间气象危害源于电离层，电离层是位于90公里及以上高度的电离层，地球磁场引导的太阳风能可在电离层造成各种不可预测和有害的影响。它导致电流流动，在被称为焦耳加热的过程中加热大气，进而导致大气向上膨胀，对卫星产生阻力，从而使它们的轨道更难预测，并缩短它们的寿命。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，与上面磁层的粒子降水有关，这改变了电离层的结构。此外，它引起等离子体不稳定，导致电离层变得波纹，从而散射来自卫星的无线电波，从而干扰通信和GPS。尽管这种空间天气灾害的大范围分布在全球环流模式中得到了相对较好的再现，但发生在比模式网格更小的空间尺度上的物理现象却知之甚少，这阻碍了预报的改进。Finesse项目将利用位于斯堪的纳维亚半岛北部的由NERC资助的新的、独特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方框中水平方向约200公里、垂直方向约800公里处的电离层结构，以成像导致空间天气影响的过程。FINESSE还将利用一台新一代相干散射雷达来测量电离层运动，三台中性风成像仪用于测量热层与电离层之间的相互作用，三台全天极光相机用于观测上方磁层的降水区域，一台精细的极光成像仪用于观测比EISCAT_3D所能探测的还要精细的空间和时间尺度的极光结构，以及一台射电望远镜和全球定位系统接收器网络来观测来自宇宙源和卫星的无线电信号的闪烁。1)确定焦耳加热的小尺度来源，将这些放在极光扰动的大背景下，确定焦耳加热和卫星阻力之间的联系，并结合这些结果来改进预报模式。2)确定小尺度电离层结构的原因，并了解这如何导致无线电信号的闪烁。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的耦合物理，极光过程在加热和构造电离层和大气中所起的作用，FINESSE将与空间气象预报员和其他利益攸关方联络，以传播对产生空间气象危害的小范围过程的更多了解，并将其转化为对联合王国的重大经济利益。