Thermal plasma acceleration and outflows in the Earth’s ionosphere

地球电离层中的热等离子体加速和流出

• 批准号: RGPIN-2014-06069
• 负责人: Yau, Andrew
• 金额: $ 3.93万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2017
• 资助国家: 加拿大
• 起止时间: 2017-01-01 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=633488
• 关键词: Thermal; plasma; acceleration; outflows; Earth

Ion outflows play an important role in the coupling of the Earth’s ionosphere to its thermosphere and its magnetosphere: they constitute a significant source of plasma for the magnetosphere - the region in near-Earth space dominated by the Earth’s magnetic field. The overarching long-term goal of the proposed research is (a) to unravel the underlying plasma acceleration and transport processes of the different ion outflows and (b) to determine and quantify the effects of these outflows on the magnetosphere-ionosphere-thermosphere (MIT).Ion outflow populations may be classified into two categories: thermal and suprathermal. Contrary to earlier theoretical expectations, significant fluxes of “heavy” oxygen ions were found in thermal-energy “light ion polar wind” above their expected peak altitude in the presence of the Earth’s gravity, and previously “hidden” cold hydrogen ions (due to spacecraft charging) were recently discovered in the distant magnetosphere. These observations underscore the important direct influence of thermal outflows on the dynamics of the magnetosphere, and highlight important gaps in our knowledge on the different outflows and their interconnections.The short-term objectives of the proposed research projects are to fill several specific knowledge gaps by investigating (a) the role or influence of interplanetary magnetic field (IMF) and geomagnetic activity on plasma outflows, (b) the source mechanisms for thermal ion heating or acceleration and (c) the effect of ion-neutral collisions on plasma outflow in the topside polar ionosphere (300–1000 km), and (d) the role of convection electric field in the transport and intermixing of different outflow species and (e) their fates in the high-altitude magnetosphere (>10,000 km). We plan to engage four graduate (2 Masters and 2 PhD) and two postdoctoral students in data analysis and modeling research projects on (1) the influence of the IMF on dayside thermal outflows and polar ion composition distributions, (2) storm-time atomic nitrogen and molecular ion acceleration at F-region and topside altitudes, (3) the effects of ion-neutral collisions on thermal polar wind and auroral bulk flow and the Solar Cycle dependence of these effects, (4) the role of ion convection in plasma intermixing at high altitudes, and (5) centrifugal ion acceleration of low-energy ions at high altitudes. The data analysis projects will entail detailed and statistical analyses of observation data from the CASSIOPE Enhanced Polar Outflow Probe (e-POP) and complementary data from the SuperDARN radar. CASSIOPE was launched successfully on September 29, 2013 and placed into a polar orbit of 325 × 1500 km. Science operation of its eight instruments started sequentially in late October 2013 as the respective instruments completed commissioning. The modeling projects will involve simulation of particle trajectories in time-dependent electric and magnetic fields in the magnetosphere, using recently developed numerical codes. In terms of expected significance, each project will potentially produce an important scientific first on topside ionospheric ion outflow: including composition observation of IMF-driven dawn-dusk outflow asymmetry; molecular ion acceleration and resulting oxygen/nitrogen geo-corona in the topside ionosphere; solar variability of outflow within a solar rotation; co-existing H+ and O+ ions in the nascent polar wind; and “partially” gravitationally trapped oxygen ions capable of reaching centrifugal acceleration altitude, respectively. The research will advance our knowledge in MIT coupling, and our long-term goal to unravel the underlying plasma processes of ion outflows and to determine and quantify their effects on the MIT system.

离子流出在地球的电离层中起着重要的作用，是热层的，是磁波的磁源性 - 在地球磁场的近乎墨西哥空间中的区域。 a）揭开潜在的等离子体加速蛋白INE并量化流出对磁圈 - 心层的影响（MIT）。ION流出种群可能分为类别：与较早的理论期望相反，在理论上的预期相反，在“沉重”离子中发现了重要的“重”磁体。在地球重力的存在下，在其预期峰值上方的热能“轻离子极风”，并在遥远的磁质上发现了以前“隐藏”的“隐藏”冷氢离子（由于航天器充电而引起的）。磁性悬浮液的动态流出及其拟议研究项目的互连目标是通过（a）（a）（a）（a）填补差距的差距，a）（a）角色或行星际磁场（IMF）和在血浆中的地磁活性，这是对热离子的源机制的作用加热或加速度以及（c）离子中性碰撞对顶部极性电离层中等离子体流出的影响（t）公约电场在运输中的作用和国际在不同流出物种中的作用以及（e）高含量磁极> 10,000公里）。 （3）离子中性碰撞对热极风和极光散装流量以及效应的太阳周期依赖性的影响，对流的作用，在Centrifugelerati对对流中的作用，对流在对流中的作用，以及对流在对流中的作用高空的低能离子将需要详细说明，统计分析来自Cassiope增强的观测数据，增强了极性流出探针（E-POP），并在2013年9月29日将其放入SuperDarn雷达。 325 x 1500 km的极性轨道在2013年后期开始依次开始。顶部离子流出：包括imf-dusk的组成分子离子加速度和氮气层中的氮气层；提高我们在MIT耦合方面的知识，以及我们的长期目标，即基础离子流出的等离子体过程，并确定和量化其对MIT系统的影响。