NSWP: Investigation of the Plasma Source for Storm Enhanced Densities and its Relationship to Sub-auroral Polarization Stream (SAPS)

风暴增强密度(SED)在主要磁暴期间被观测到，并与亚极光极化流(SAPS)密切相关。可获得的有关这些现象的大部分信息来自于空间或时间覆盖范围有限的观测。因此，这些数据既不能提供现象的全貌，也不能解决潜在的物理问题。本研究项目将尝试使用内部磁层和热层-电离层-等离子体层系统的自洽耦合模式来模拟SEDS和SAPS，以便更好地理解电离层和等离子体层中等离子体的风暴时间再分布。所使用的耦合模式包括了所有风暴时间驱动因素，并模拟了热层、电离层和等离子体层的后续响应。该模型的一个特别值得注意的特点是，它明确包括了环电流和产生SAPS的电离层之间的相互作用过程。该模型包括一个真实的磁场，这将使电离层动力学和电动力学的纵向相关性得以解决，特别是关于美国经度区段是否独特的问题。需要进行的三个具体研究课题是：SEDS的等离子体源的调查，SEDS和SAPS的高度耦合，以及电导折减与SAPS电场的相互作用。将根据观测结果进行广泛的模型验证，特别是对总电子含量的梯度进行验证，以及对产生SED的电场和全球等离子体传输进行全面分析。五个特殊的地磁风暴将是调查的重点。这些事件发生在2000至2005年间，并已成为若干出版物的主题。调查的更广泛影响包括对热层和电离层对磁暴的反应的新见解，这是空间气象方案的一个目标，以及增进对磁层-电离层耦合的了解。该项目可能有助于产生对总电子含量梯度的预测能力，这具有重要的空间气象应用，例如用于全球定位系统和用于商用飞机导航的广域增强系统(WAAS)。该项目由一位即将开始她的研究生涯的女科学家领导。

Storm Enhanced Densities (SEDs) have been observed during major magnetic storms and have been strongly associated with sub-auroral polarization streams (SAPS). Much of the information that is available about these phenomena originates from observations with limited coverage in space or time. These data therefore cannot provide a complete picture of the phenomena nor address the underlying physics. This research project will attempt to model the SEDs and SAPS with a self-consistently coupled model of the inner magnetosphere and thermosphere-ionosphere-plasmasphere system in order to better understand the storm-time redistribution of plasmas in the ionosphere and plasmasphere. The coupled model used here includes all the storm-time drivers and simulates the subsequent response of the thermosphere, ionosphere, and plasmasphere. A particular noteworthy feature of the model is that it explicitly includes the interaction processes between the ring current and the ionosphere that produces the SAPS. The model includes a realistic magnetic field that will enable the longitudinal dependence of the ionospheric dynamics and electrodynamics to be addressed, in particular with regards to the question of whether the American longitude sector is unique. Three particular research topics to be pursued are: investigation of the plasma source of the SEDs, the altitude coupling of the SEDs and SAPS, and the interaction between reduced conductivities and the SAPS electric field. Extensive model validation against observations will be done, particularly for the gradients in total electron content, as well as comprehensive analysis of the electric fields and the global plasma transport responsible for producing SEDs. Five particular geomagnetic storms will be the focus of the investigation. These occurred from 2000 to 2005 and have been the subject of several publications. The broader impacts of the investigation include new insights into the response of the thermosphere and ionosphere to magnetic storms, a goal of the Space Weather Program, as well as improved understanding of magnetosphere-ionosphere coupling. The project may help lead to a predictive capability for gradients in total electron content which has important Space Weather applications such as for GPS and Wide Area Augmentation Systems (WAAS) used for navigation of commercial aircraft. The project is being led by a female scientist near the beginning of her research career.