Comprehensive Study of 3D Magnetosphere-Ionospheric Current System Through the Modeling, Observations, and Applications: Auroral Electrojet Indices for the Southern Hemisphere

通过建模、观测和应用综合研究 3D 磁层-电离层电流系统：南半球极光电射流指数

• 批准号: 1744925
• 负责人: Sonya Lyatsky
• 金额: $ 37.45万
• 依托单位: Catholic University of America
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-07-01 至 2024-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1744925&HistoricalAwards=false
• 关键词: Comprehensive; Study; 3D; Magnetosphere; Ionospheric

The Earth's three-dimensional magnetosphere-ionosphere current system is an important component of the Geospace environment. These currents are driven by the interaction of solar wind (an everlasting plasma flow from the Sun) with the Earth's magnetosphere, transferring significant amounts of energy and momentum into the high-latitude ionosphere and upper atmosphere via the geomagnetic field-aligned currents. The 3D current system dynamics affect both the Northern and South Polar Regions, causing their dynamic changes and heating through the closure of these currents in the Earth's ionosphere. These currents can be modeled, but they are difficult to observe from the ground or even from space - only their effects on geomagnetic field variations (and respective indices of geomagnetic activity) can be recorded by properly placed ground-based instruments. This award will support a study of a relatively unexplored phenomenon of interhemispheric field-aligned currents through the model development and comparison of modeled results with the ground-based and satellites observations. This new model will significantly advance our understanding of the physics of space weather-driving processes in both hemispheres and development of an index describing geomagnetic activities in the Southern polar region. The latter is important because calculating this index using existing Aural Electrojet (AE) technique (that uses data from 12 geomagnetic observatories across the Northern auroral region) is not applicable to the Southern auroral region that goes over Southern Ocean for ~50% of the global coverage. There are only 5-6 Antarctic costal research stations that can contribute to this index calculations, which is much less than optimal for the traditional AE calculation technique. This research effort has the potential to significantly increase our understanding of the role played by interhemispheric currents on the dynamics of the polar and auroral regions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

地球三维磁层-电离层电流系统是地球空间环境的重要组成部分。这些电流是由太阳风(一种来自太阳的永恒等离子体流)与地球磁层相互作用驱动的，通过地磁场排列的电流将大量能量和动量转移到高纬度电离层和高层大气。3D电流系统动力学影响北极和南极地区，通过关闭地球电离层中的这些电流而导致它们的动态变化和加热。这些电流可以被模拟，但它们很难从地面或甚至从太空观察--只有它们对地磁场变化的影响(以及各自的地磁活动指数)可以通过适当放置的地面仪器来记录。该奖项将通过模型开发以及模型结果与地面和卫星观测结果的比较，支持对一种相对未被探索的半球间场向流现象的研究。这一新模式将极大地促进我们对两个半球的空间天气驱动过程的物理学的理解，并开发一个描述南极地区地磁活动的指数。后者很重要，因为使用现有的听觉电喷流(AE)技术(使用北极光区域12个地磁观测站的数据)计算这一指数不适用于覆盖全球约50%的南大洋的南极光区域。目前只有5-6个南极海岸带观测站可以参与这一指数的计算，这远远低于传统的声发射计算技术的最佳值。这项研究工作有可能显著提高我们对半球间洋流在极地和极光区域动力学中所起作用的理解。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。