A multi-instrument exploration of the cusp ionosphere

尖点电离层的多仪器探索

• 批准号: NE/V000748/1
• 负责人: Timothy Yeoman
• 金额: $ 78.74万
• 依托单位: University of Leicester
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2021
• 资助国家: 英国
• 起止时间: 2021 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FV000748%2F1
• 关键词: multi; instrument; exploration; cusp; ionosphere

At near-noon local times, at locations in the high arctic near 80 degrees North and South, the magnetic fields which originate in the conducting core of our planet extend upwards and are magnetically connected to the dayside magnetopause. This subsolar magnetopause is the point where the magnetic field of the Earth first touches the highly supersonic solar wind flow, and the interplanetary magnetic field of solar origin which is embedded in it. This creates the magnetospheric cusps, which are the primary entry points for energy of solar wind origin into the regions of space controlled by the terrestrial magnetic field, and the atmospheric regions which underlie them. This energy transfer occurs through a process called magnetic reconnection. As such, this crucial region of near-Earth space is fundamental to understanding the flow of energy, mass and momentum throughout the Earth's magnetosphere, ionosphere and upper atmosphere, and hence in our understanding of "space weather". The magnetospheric cusps are longstanding areas of research interest, but their highly variable nature, in both space and time, makes them a highly challenging region to fully understand. Here we describe a multi-instrument research programme based around an exciting new NASA space mission, TRACERS, due for launch in late 2022, on which the proposal PI is a named collaborator. The TRACERS programme relies on coordination with ground-based instrumentation. Of particular interest for TRACERS is the Svalbard region, an area of the high arctic uniquely well instrumented with, for example, numerous optical instruments and the NERC-funded EISCAT Svalbard radar. Around northern winter solstice Svalbard is in darkness at noon, and for ~10 days the moon is below the horizon. Such conditions offer a unique opportunity for multi-instrument cusp experiments involving cusp auroral optical observations. Our multi-instrument research programme requires the construction and deployment of a new state-of-the art digital imaging radar system, the Hankasalmi auroral imaging radar system (HAIRS). HAIRS will look northwards from Hankasalmi in Finland, having a field of view centred over the Svalbard region, revealing the ionospheric cusp region electrodynamics at high spatial and temporal resolution over a ~1 million square kilometre region of the ionosphere.In this programme, low earth orbit measurements of energetic ions precipitating from the cusp region taken by the twin TRACERS spacecraft will provide measurements of the temporal and spatial structuring of the cusp reconnection processes. Magnetically conjugate measurements of the footprint of the reconnection line from HAIRS and associated ground-based instrumentation, will measure the length and the location of the reconnection line. HAIRS will provide an analysis of the boundary motion, and of the convection velocities detected near the boundary, allowing a calculation of the reconnection rate mapped down to the ionosphere. Such a combination of instrumentation will provide an unprecedented opportunity to understand the temporal and spatial behaviour of cusp reconnection and its role in controlling terrestrial space weather. Outside of the science programme described here, HAIRS will offer vital complementary datasets to support the upcoming NERC-funded EISCAT 3D radar system at lower latitudes in Scandinavia, coming on stream in 2021 which will also lie in the HAIRS field of view. HAIRS will also directly complement the Solar wind Magnetosphere Ionosphere Link Explorer (SMILE), launching in 2023, a joint mission between the European Space Agency (ESA) and the Chinese Academy of Sciences (CAS). The innovative SMILE wide-field Soft X-ray Imager (SXI), provided by the UK Space Agency and other European institutions, will obtain unique measurements of the regions where the solar wind impacts the magnetosphere, regions which are directly magnetically connected to the area under study in this programme.

在接近中午的当地时间，在北极高纬度地区接近80度的地方，起源于我们星球导电核心的磁场向上延伸，并与昼侧磁层顶磁连接。太阳下磁层顶是地球磁场与太阳风的超音速气流以及嵌入其中的太阳系星际磁场的第一个接触点，这就形成了磁层尖点，它是太阳风源能量进入地球磁场控制的空间区域及其下方大气区域的主要入口。这种能量转移是通过一个称为磁重联的过程发生的。因此，近地空间的这个关键区域对于了解整个地球磁层、电离层和高层大气的能量、质量和动量流动至关重要，因此对于我们理解“空间天气”至关重要。磁层尖点是长期的研究兴趣领域，但其在空间和时间上的高度可变性使其成为一个非常具有挑战性的区域。在这里，我们描述了一个多仪器的研究计划，围绕一个令人兴奋的新的美国宇航局空间使命，跟踪器，由于在2022年底发射，该提案PI是一个指定的合作者。跟踪器方案依赖于与地面仪器的协调。TRACERS特别感兴趣的是斯瓦尔巴德地区，这是北极高纬度地区的一个独特地区，配备了许多光学仪器和NERC资助的EISCAT斯瓦尔巴德雷达。在北方冬至前后，斯瓦尔巴特群岛的中午是一片黑暗，大约有10天月亮在地平线以下。这种条件为涉及尖点极光光学观测的多仪器尖点实验提供了独特的机会。我们的多仪器研究方案需要建造和部署一个新的最先进的数字成像雷达系统，即汉卡萨尔米极光成像雷达系统。HAIRS将从芬兰的汉卡萨尔米向北观测，视野集中在斯瓦尔巴德群岛地区，以高空间和时间分辨率揭示电离层尖点区域电动力学，电离层面积约为100万平方公里。由双跟踪器航天器对从尖点区域沉淀的高能离子进行的低地球轨道测量，将提供时间和空间的测量结果尖点重联过程的结构。从HAIRS和相关的地面仪器对重连线的足迹进行磁共轭测量，将测量重连线的长度和位置。HAIRS将提供边界运动分析和边界附近探测到的对流速度分析，从而可以计算映射到电离层的重连率。这种仪器组合将为了解尖点重联的时空行为及其在控制地球空间天气方面的作用提供前所未有的机会。在这里描述的科学计划之外，HAIRS将提供重要的补充数据集，以支持即将在斯堪的纳维亚半岛低纬度地区推出的NERC资助的EISCAT 3D雷达系统，该系统将于2021年投入使用，也将位于HAIRS的视野中。HAIRS还将直接补充2023年发射的太阳风磁层电离层链路探测器（SMILE），这是欧洲航天局（ESA）和中国科学院（CAS）之间的联合使命。由联合王国航天局和其他欧洲机构提供的创新性SMILE宽场软X射线成像仪（SXI）将获得太阳风影响磁层的区域的独特测量结果，这些区域与本方案所研究的区域直接磁连接。