Measurements of Midlatitude Thermospheric Dynamics and Temperature

该项目将继续在波多黎各阿雷西博观测站(1980年开始)和马萨诸塞州干草堆观测站(1989年开始)使用一种称为法布里-珀罗涉仪的高灵敏度仪器继续测量热层(海拔约80公里至600公里的大气区域)中的风和温度。这两个观测站拥有两个强大的雷达系统，称为非相干散射雷达(ISRS)，可以测量同一区域(也称为电离层)的大气电离部分。对于热层-电离层系统的实际物理建模和有效的空间天气预报来说，这些测量的组合是必要的。干草堆观测站和阿雷西博观测站使用的这种浮点探测器是双光束成像系统，以光谱分辨率采样Oi 6300？(红色)和5577？(绿色)气辉发射，以解决与热层中中性物质的整体流动有关的多普勒频移。数据产品包括名义发射高度240公里和97公里处的气辉亮度、温度、视线风速、风速的经向和纬向分量以及速度梯度。在这个为期三年的项目中，每年将产生200-300个晚上的数据。这一举措每天早上在数据收集停止后维护FPI、进行观察、分析数据并将数据发布到公共Madrigal数据库中。新的和存档的数据(自1980年在阿雷西博天文台和1989年在干草堆天文台)将被用来实现四个科学目标：1)通过执行双基地实验来明确地分离垂直风矢量，测试用单站FPI测量的垂直风向的有效性。2)收集每个月(过去和未来)的数百个垂直风速测量值，并建立月风速与当地时间的多项式拟合经验模型。3)研究1980-2010年探测到的平均F区风矢量的长期旋转是否从2011-2023年持续。如果是这样的话，磁场取向的长期迁移将被评估为可能的原因。4)评估中夜最高温度与F区热层中向上的强垂直风之间的可能关系。第五个项目目标是业务目标，即为业务空间天气预报建立实时数据产品报告。这项研究加强了研究和教育的基础设施。FPI可在设施中供社区使用，用户可以设计和执行独立的实验。此外，准确和容易获得的(即使是实时的)中性风测量是应对空间天气预报挑战的一个基本数据要素，这在空间导航和通信资产的态势认识方面具有广泛的社会效益的巨大潜力。该项目维护的工具也经常用于每个设施的本科生活力研究项目。该奖项反映了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。

This project will continue the measurements of winds and temperatures in the thermosphere (a region of atmosphere between about 80 km to 600 km above sea level) at Arecibo Observatory, Puerto Rico (started in 1980) and at Haystack Observatory, Massachusetts (started in 1989) using a highly sensitive instrument called Fabry-Perot interferometers (FPIs). The two observatories have two powerful radar systems called Incoherent Scatter Radars (ISRs) that can measure the ionized part of the atmosphere in the same region (also called ionosphere). Combination of such measurements are needed for realistic, physics-based modeling of the thermosphere-ionosphere system, and for effective forecasting of Space Weather.This FPIs used at Haystack Observatory and Arecibo Observatory are dual-beam imaging systems sampling the OI 6300Å (red) and 5577Å (green) airglow emissions with spectral resolutions that resolve the Doppler shift associated with the bulk flow of neutral species in the thermosphere. The data products include airglow brightness, temperature, line-of-sight wind velocity, meridional and zonal components of the wind velocity and velocity gradients at the nominal emission altitudes of 240 km and 97 km. 200-300 nights of data will be generated each year during this three-year project. This initiative maintains the FPIs, performs the observations, analyses the data, and posts the data in the public Madrigal data base each morning after data collection stops. New and archived data (since 1980 at Arecibo Observatory and 1989 at Haystack Observatory) will be used to achieve four scientific goals: 1) Test the validity of vertical winds measured with a monostatic FPI by performing a bistatic experiment to unambiguously isolate the vertical wind vector. 2) Gather hundreds of vertical wind measurements each month (past and future) and establish monthly velocity versus local time empirical models from polynomial fits to the data. 3) Investigate whether a long-term rotation of the average F-region wind vector detected in the years 1980-2010 continues from 2011-2023. If so, the long-term migration of the magnetic field orientation will be evaluated as a possible cause. 4) Evaluate a possible correlation between the Midnight Temperature Maximum and strong, upward vertical winds in the F-region thermosphere. A fifth project goal is an operational objective to establish real-time data product reporting for operational Space Weather forecasting.This research enhances infrastructures for research and education. The FPIs are available for community use at the facilities, and users can design and perform independent experiments. In addition, accurate and accessible (even in real-time) neutral wind measurements are an essential data element in responding to the challenge of Space Weather forecasting, which carries significant potential for broad societal benefit in the context of situational awareness for space-based navigation and communication assets. The instruments maintained by this project are also commonly used for projects in the vigorous Research Experience for Undergraduates programs at each facility.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.