Study of the Earth's ionosphere with ground-based radars and Swarm satellites

利用地面雷达和 Swarm 卫星研究地球电离层

• 批准号: RGPIN-2022-03001
• 负责人: Koustov, Alexandre
• 金额: $ 2.04万
• 依托单位: University of Saskatchewan
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=763195
• 关键词: Study; Earth; ionosphere; ground; based

The Earth's ionosphere is a conductive layer in the upper atmosphere. It is controlled by internal processes such as neutral winds, as well as the interaction between the Earth's magnetic field and the solar wind which carries the embedded interplanetary magnetic field (IMF). The global-scale electric field established in the ionosphere is a critical element in these interactions at the magnetospheric level. In the ionosphere, the electric field in combination with the geomagnetic field redistributes plasma at F region heights (~300 km) and drives strong electric currents at E region heights (~100 km). The proposed research seeks to improve our understanding of the distribution and circulation of ionospheric plasma as a function of solar wind conditions. The focus is on the identification of how ionospheric plasma motions lead to the formation of plasma structures of various scales. This will be achieved through synchronized measurements with several instruments properly positioned on the ground and in space. The research can be categorized into four themes. (1)  Study of meso-scale ionospheric plasma circulation patterns as a function of external drivers with a focus on IMF Bz>0 condition by observing simultaneous data from multiple SuperDARN radars near the North and South Poles. SuperDARN data will be supplemented by electric field measurements from the Swarm satellites and the incoherent scatter radars (ISR) at Resolute Bay. Observations will be tested against theoretical models of magnetospheric plasma flow.   (2) Examination of long-term trends and inter-hemispheric differences in electron density distribution and how this affects the occurrence of SuperDARN echoes. Additional focus will be on the topside ionosphere where a combination of ISR and Swarm measurements would provide new information on the poorly investigated High Arctic ionosphere. (3) Identifying the sources of mesoscale ionospheric structures with enhanced electron density persistent at middle latitudes. These are related to neutral winds and waves resulting from either intense particle precipitation events at high latitudes or atmospheric processes at the edges of the polar vortex. (4) Mechanisms of small-scale (decameter-meter) wave-like electron density irregularity formation at E region heights in the presence of strong electric currents. Joint HF and VHF observations will be tested against recent non-linear theories. The planned research will contribute to the Canadian efforts in forecasting harmful "space weather" events affecting pipelines through excessive corrosion and predictions of HF communication systems' operability at high latitudes critical for the airline operators and air-defense monitoring with over-the-horizon radars. The research program focuses on training undergraduate and graduate students for work in the Canadian satellite, aerospace, and related industries, as well as for agencies performing atmospheric environment monitoring.

地球电离层是高层大气中的导电层。它受内部过程控制，例如中性风，以及地球磁场与携带嵌入行星际磁场（IMF）的太阳风之间的相互作用。在电离层中建立的全球尺度电场是磁层一级这些相互作用的关键要素。在电离层中，电场与地磁场结合在F区高度（~300 km）重新分布等离子体，并在E区高度（~100 km）驱动强电流。拟议的研究旨在提高我们对电离层等离子体的分布和循环随太阳风条件变化的认识。重点是确定电离层等离子体运动如何导致各种尺度的等离子体结构的形成。这将通过在地面和空间适当放置的几个仪器进行同步测量来实现。研究可以分为四个主题。(1)通过观测南极和北极附近多个SuperDARN雷达的同步数据，研究作为外部驱动因素函数的中尺度电离层等离子体环流模式，重点是IMF Bz>0条件。SuperDARN数据将由Swarm卫星和Resolute Bay的非相干散射雷达（ISR）的电场测量结果补充。观测结果将对照磁层等离子体流的理论模型进行检验。 （2）检查电子密度分布的长期趋势和半球间差异，以及这如何影响SuperDARN回波的出现。额外的重点将放在顶部电离层上，ISR和Swarm测量的组合将提供关于调查不足的高北极电离层的新信息。 (3)中纬度持续增强电子密度的中尺度电离层结构源的识别。这些都与高纬度地区强烈的粒子降水事件或极地涡旋边缘的大气过程造成的中性风和波有关。 (4)在强电流存在下E区高度处小尺度（十米-米）波状电子密度不规则性形成的机制。联合高频和甚高频观测将根据最近的非线性理论进行测试。计划中的研究将有助于加拿大努力预测有害的“空间天气”事件，这些事件通过过度腐蚀影响管道，并预测高频通信系统在对航空公司运营商至关重要的高纬度地区的可操作性，以及利用超视距雷达进行防空监测。该研究计划的重点是培养本科生和研究生在加拿大卫星，航空航天和相关行业的工作，以及执行大气环境监测机构。