CEDAR: Solar Extreme Ultraviolet Irradiance Effects on the Coupled Ionosphere-Thermosphere System

耦合，能量学和大气区域动力学（CEDAR）计划是一个基础广泛，社区指导的高层大气研究计划。它的目的是了解从中层大气向上通过电离的上层大气层进入外层空间的大气区域在区域和全球尺度上的耦合、能量学、化学和动力学方面的行为。感兴趣的过程与从低层大气向上传播的扰动以及来自上方的太阳辐射和粒子输入有关。 该项目将为实现CEDAR的目标在了解光谱极紫外部分的太阳辐照度输入变化引起的高层大气变化方面提供基本成果。一个具体目标是首次直接确定测得的辐照度水平与观测到的高层大气条件之间的关系。这项研究的结果将为验证和限制基于物理学的高层大气模型提供一个独特的观测基准。这些模型对于理解和预测近地空间环境中可能严重影响卫星导航、无线电波通信和电网等技术系统的关键过程至关重要。该项目将支持德克萨斯大学达拉斯分校的一名研究生的教育。该项目的主要目标是量化电离层相对于TIMED和SDO航天器对太阳极紫外辐射进行的直接光谱分离测量的响应。这种方法构成了一个巨大的改进，以前的研究的基础上代理。C/NOFS和DMSP航天器将在一定高度范围内提供电离层参数的相应测量。该数据集跨越一个以上的太阳周期，可以使用先进的统计分析技术，并将与SAMI-2模型一起用于解决与理解电离层对太阳极紫外线变化的反应有关的悬而未决的科学问题。有待研究的有趣问题包括高层大气中性和电离成分的反应的相对重要性和相互作用。

The Coupling, Energetics, and Dynamics of Atmospheric Regions (CEDAR) program is a broad-based, community-guided, upper atmospheric research program. It is aimed at understanding the behavior of atmospheric regions from the middle atmosphere upward through the ionized upper layers of the atmosphere and into outer space in terms of coupling, energetics, chemistry, and dynamics on regional and global scales. The processes of interest are related to perturbations that propagate upward from the lower atmosphere as well as to solar radiation and particle inputs from above. This project will contribute fundamental results towards CEDAR goals in the area of understanding the variability in the upper atmosphere caused by the changing input of solar irradiance in the extreme ultra-violet part of the spectrum. A specific goal is to determine directly, for the first time, the relationship between measured irradiance levels and observed conditions in the upper atmosphere. The results of this study will provide a unique observational benchmark for validating and constraining physics-based models of the upper atmosphere. Such models are essential for understanding and predicting critical processes in the near-Earth space environment that can severely impact technological systems such as satellite navigation, radio wave communication, and electric power grids. The project will support the education of a graduate student at University of Texas at Dallas. The main goal of this project is to quantify the response of the ionosphere relative to direct, spectrally separated measurements of solar extreme ultraviolet (EUV) radiation from the TIMED and SDO spacecraft. This approach constitutes an immense improvement over previous studies based on proxies. The C/NOFS and DMSP spacecraft will provide corresponding measurements of ionospheric parameters at a range of altitudes. This dataset, spanning more than a solar cycle, allows for the use of advanced statistical analysis techniques and will be used together with the SAMI-2 model to address outstanding science questions related to understanding the ionospheric response to solar EUV variability. Interesting questions to be investigated include the relative importance of and interaction between the responses in the neutral and ionized components of the upper atmosphere.