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

地球的电离层是上层大气中的导电层。它由内部过程控制，如中性风，以及地球磁场和太阳风之间的相互作用，太阳风携带嵌入的行星际磁场（IMF）。在电离层建立的全球尺度电场是磁层水平上这些相互作用的关键因素。在电离层中，电场与地磁场的结合使等离子体在F区高度（~300 km）重新分布，并在E区高度（~100 km）驱动强电流。提出的研究旨在提高我们对电离层等离子体的分布和循环作为太阳风条件的函数的理解。重点是确定电离层等离子体运动如何导致各种尺度等离子体结构的形成。这将通过在地面和太空中适当放置的几台仪器进行同步测量来实现。这项研究可以分为四个主题。(1)利用南极和北极附近多台SuperDARN雷达同步观测资料，研究了外部驱动因素对中尺度电离层等离子体环流的影响，重点研究了IMF Bz>条件。superdam数据将由Swarm卫星和Resolute湾的非相干散射雷达（ISR）的电场测量数据补充。观测结果将根据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及其如何影响superdamn回波的发生。额外的重点将放在上层电离层上，ISR和Swarm测量的结合将为研究不足的高北极电离层提供新的信息。(3)确定中纬度地区电子密度持续增强的中尺度电离层结构的来源。这与高纬度地区的强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中性波有关。(4)强电流存在下E区高度小尺度（十米）波状电子密度不规则形成机制。联合高频和甚高频观测将根据最近的非线性理论进行检验。计划中的研究将有助于加拿大预测通过过度腐蚀影响管道的有害“空间天气”事件，并预测高频通信系统在高纬度地区的可操作性，这对航空公司运营商和超视距雷达的防空监测至关重要。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工作，以及为执行大气环境监测的机构工作。

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.