Collaborative Research: CEDAR: Causal Relationships of Ion-neutral Coupling Processes at Mid-latitudes

合作研究：CEDAR：中纬度地区离子中性耦合过程的因果关系

• 批准号: 1452203
• 负责人: Gary Bust
• 金额: $ 17.3万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-01 至 2019-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1452203&HistoricalAwards=false
• 关键词: Collaborative; Research; CEDAR; Causal; Relationships

The goal of this study is to advance our understanding of the coupling and causal links between high-latitude forcing of the thermosphere and mid-latitude plasma density structuring during both quiet and storm times. The study will also characterize the relative importance of spatial/temporal variation at the high-latitude boundary between the magnetosphere and ionosphere in generating observed variability in the mid-latitudes. The knowledge gained will impact the development of future models by identifying any missing physics in the models as well as the spatial/temporal resolutions required to capture relevant processes. Improving modeling is critical to enabling space weather forecasting capabilities, and will enhance the infrastructure for research and education. This project will address two fundamental questions: 1) What is the cause/effect relationship between high-latitude forcing on the neutral winds and the response of electron densities at mid-latitudes, especially during geomagnetic storm conditions? 2) What is the relationship between spatial/temporal variability within the high-latitude drivers and the variability observed within the mid-latitude neutral winds and ionospheric structure? Observations of mid-latitude thermospheric winds and temperatures made by the North American Thermosphere-Ionosphere Observation Network (NATION) of Fabry-Perot interferometers (FPI) will be coupled with time-dependent 3D electron density estimates from the Ionospheric Data Assimilation Four Dimensional (IDA4D) assimilative model. The source of the dynamics observed in the thermospheric neutral winds and electron density will be investigated through exercising an inversion algorithm (Estimating Model Parameters from Ionospheric Reverse Engineering; EMPIRE) developed to estimate the ionospheric drivers from three-dimensional, time-evolving distributions of ionospheric electron densities. The first-principles Global Ionosphere Thermosphere Model (GITM) will also be used to elucidate the underlying physics responsible for the coupling. This study will contribute to the education and training of graduate students at the University of Illinois and the University of Michigan.

这项研究的目的是增进我们对高纬度强迫热层和中纬度等离子体密度结构之间的耦合和因果联系的理解，无论是在平静时期还是暴风雨时期。这项研究还将确定磁层和电离层之间高纬度边界的空间/时间变化在产生中纬度观测变化方面的相对重要性。所获得的知识将通过查明模型中任何遗漏的物理以及捕捉相关过程所需的空间/时间分辨率来影响未来模型的发展。改进建模是实现空间天气预报能力的关键，并将加强研究和教育的基础设施。这个项目将解决两个基本问题：1)高纬度对中性风的强迫与中纬度电子密度的反应，特别是在地磁风暴条件下的反应之间的因果关系是什么？2)高纬度驱动因素内的空间/时间变化与在中纬度中性风和电离层结构内观测到的变化之间的关系是什么？由北美热层-电离层观测网(法布里-珀罗涉仪)对中纬度热层风和温度进行的观测将与电离层数据同化四维(IDA4D)同化模式中随时间变化的3D电子密度估计相结合。将通过实施一种反演算法(估计电离层反向工程的模型参数)来调查在热层中性风和电子密度中观察到的动力学的来源，该算法是为从电离层电子密度的三维、随时间演变的分布估计电离层驱动因素而开发的。第一原理全球电离层热层模型(GITM)也将被用来阐明造成这种耦合的基本物理原因。这项研究将有助于伊利诺伊大学和密歇根大学研究生的教育和培训。