High-resolution Mapping of Thermospheric Wind and Temperature Fields near the Equatorward Edge of the Antarctic Polar Cap to understand Coupling to Layers both above and below

地球高层大气在100公里以上的高度受到高度多变的天气的影响。对这一区域的观测通常显示出长时间(几天到几周)相对平静的条件，不时会出现只能被描述为“风暴”的大扰动。然而，即使是安静的时间，也会表现出大量的、往往看起来是随机的日常变化背景。在对流层中，大风暴在内部发展，不需要外部强迫或区域边界条件造成的突然脉冲变化。虽然内部不稳定也对地球电离层和热层(特别是在低纬地区)起作用；相反，大部分热层天气是由来自上方和下方区域的强迫直接从外部驱动的。向上传播的波和潮汐对低水平的逐日变化做出了无处不在的贡献，而太阳辐射、太阳风和地球磁层动力学的波动驱动了广泛的热层扰动-并完全导致了风暴和其他大型事件。该项目的主要目标是了解大大小小热层天气逐日波动的根源。两台最先进的测量热层风和温度的遥感仪器将部署在南极洲，其纬度已被先前的研究证明是最极端和最复杂的热层天气行为的所在地。虽然之前的工作多年来一直在测量全球的热层风和温度，但在这些地磁纬度上，从来没有仪器的灵敏度、分辨率和视场接近拟议的全天成像设计所达到的水平。这些新型法布里-珀罗光谱仪的性能比南极麦克默多站和南极站上一代仪器的性能高出两个数量级以上，这将为地球极冠热层的流体动力学开启革命性的新见解。这一奖项将解决一些具体的悬而未决的大气研究问题：在穿过极冠的普遍反太阳的中性气流中观察到的复杂的逐日变化的主要来源是什么？极冠内观测到的温度和模拟的温度和潮汐幅度之间的差异是什么机制造成的？从极光椭圆形向极地传播的热层重力波是否向极冠热层沉积了大量的热量和/或动量？在南极热层温度的长期记录中，有没有人为气候变化和/或太阳活动减少的迹象？尖端科学、国际合作和南极旅行为实现该项目的教育和推广目标提供了理想的机会。该项目预计将产生更广泛的影响，包括培训一名博士研究生，促进南极洲的国际科学协作与合作，并提供对卫星运营商、通信者和导航员有业务价值的实时和档案数据。

Earth's upper atmosphere at altitudes above 100-km is subjected to highly variable weather. Observations of this region, known as the thermosphere, commonly show long periods (days to weeks) of relatively placid conditions, punctuated by large disturbances that can only be described as "storms". However, even quiet times exhibit a substantial and often seemingly random background of day-to-day variability. In the troposphere, large storms develop internally, without a requirement for sudden impulsive changes by externally imposed forcing or regional boundary conditions. While internal instability does also play a role in Earth's ionosphere and thermosphere (especially at low latitudes); much of the thermospheric weather is instead directly driven from outside by forcing from regions above and below. Upward propagating waves and tides make a ubiquitous contribution to the low-level day-to-day variability, whereas fluctuations in the solar radiation, solar wind, and Earth's magnetosphere dynamics drive a broad spectrum of thermospheric perturbations - and are entirely responsible for driving storms and other large events. The primary goal of this project is to understand the origins of day-to-day fluctuations in thermospheric weather, both large and small. Two state-of-the-art remote sensing instruments measuring thermospheric wind and temperature will be deployed in Antarctica, at latitudes that have been shown by previous studies to host the most extreme and complex thermospheric weather behavior. While previous work has measured thermospheric winds and temperatures across the globe for many years, there have never been instruments at these geomagnetic latitudes with anything even close to the proven sensitivity, resolution, and field of regard that are achieved by the proposed all-sky imaging design. Demonstrated performance of these new Fabry-Perot Spectrometers exceeds that of the previous generation of instruments at the Antarctic McMurdo and South Pole stations by more than two orders of magnitude, which will open revolutionary new insights in the fluid dynamics of Earth's polar-cap thermosphere. This award will address a number of specific outstanding questions of aeronomical research: What is the main source of complex day-to-day variability that has been observed in the generally anti-sunward neutral flow across the polar cap? What are the mechanisms responsible for discrepancies between observed and modeled temperatures and tidal amplitudes within the polar cap? Do thermospheric gravity waves, propagating poleward from the auroral oval, deposit a significant flux of heat and/or momentum into the polar cap thermosphere? Are there any signatures of anthropogenic climate change and/or declining solar activity in the long-term record of thermospheric temperatures at South Pole?Cutting-edge science, international partnership, and travel to Antarctica provide an ideal opportunity to achieve the project's education and outreach goals. Anticipated broader impacts from this project include training of a Ph.D. graduate student, furthering international scientific collaboration and cooperation in Antarctica, and providing real-time and archive data that will be of operational value to satellite operators, communicators, and navigators.