CEDAR: Analysis of CEDAR-HLPS Polar Cap Arc Observations Using Model Observation Comparison Techniques

CEDAR：使用模型观测比较技术分析 CEDAR-HLPS 极冠弧观测

• 批准号: 9302165
• 负责人: Jan Sojka
• 金额: $ 8.45万
• 依托单位: Utah State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1993
• 资助国家: 美国
• 起止时间: 1993-06-15 至 1996-03-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9302165&HistoricalAwards=false
• 关键词: CEDAR; Analysis; HLPS; Polar; Cap

The CEDAR High Latitude Plasma Structures (HLPS) initiative has carried out several observational campaigns to acquire comprehensive data bases on Sun-aligned polar cap arcs (SA). At USU, two distinct modeling efforts have produced models that pertain to polar cap Sun-aligned arcs, namely, an upgraded Time Dependent Ionospheric Model with embedded Sun-aligned polar cap arcs (TDIM-SA) and an MHD coupled magnetosphere-ionosphere polar cap Sun-aligned arc model (M-I SA). The PIs propose to use these two models in five specific collaborative investigations utilizing these CEDAR-HLPS data lets, each investigation having a specific scientific goal. The first and second investigations pertain to understanding the dawn-dusk (or vice versa) drift associated with SA and their multiple arc, striated, nature. Both of these studies use the M-I SA model which exhibits both of these features. The third is to use the HLPS observations of many electrodynamic and plasma parameters to validate the TDIM-SA model, especially the model prediction that the cross arc drift speed is a key parameter. Our fourth study is to understand the strong convection rotation observed in the vicinity of polar cap and auroral arcs during times when the arc is changing. Again, this type of feature is present in the M-I SA simulations. Strong plasma depletions have been observed adjacent to SAs and have been tentatively associated with electrodynamic current closure requirements. For this fifth study, we will use the TDIM-SA to quantify all the electrodynamic parameters and evaluate if this hypothesis is the source of the plasma depletions.

CEDAR高纬度等离子体结构（HLPS）倡议 进行了几次观测活动， 太阳排列的极冠弧（SA）的综合数据库。 在 USU，两个不同的建模工作已经产生了模型， 与极冠太阳对齐的弧有关，即升级的时间 嵌入向日极冠的非独立电离层模式 弧（TDIM-SA）和磁流体耦合磁层-电离层极 帽太阳对准弧模型（M-I SA）。 PI建议使用这些 五项具体合作调查中的两种模式， 这些CEDAR-HLPS数据集，每个调查都有一个特定的 科学目标。 第一次和第二次调查涉及 了解黎明-黄昏（或反之亦然）漂移与 SA和它们的多弧、条纹、性质。 这两项研究 使用具有这两个特征的M-I SA模型。 的 第三是利用HLPS观测到的许多电动力学， 等离子体参数，以验证TDIM-SA模型，特别是 模型预测的跨弧漂移速度是一个关键参数。 我们的第四个研究是了解强对流旋转 在极帽和极光弧附近观测到的 当电弧变化时。 同样，这种类型的特征存在于 在M-I SA模拟中。 强烈的等离子体消耗 在SA附近观察到，并暂时与 电动电流闭合要求。 对于第五项研究， 我们将使用TDIM-SA来量化所有的电动力学 参数，并评估该假设是否是 血浆消耗