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

在海拔100公里以上的地球上层大气受到高度多变的天气的影响。对这个被称为热层的区域的观测通常显示出长时间（数天到数周）相对平静的条件，偶尔会出现只能用“风暴”来形容的大扰动。然而，即使是安静的时候，也会表现出大量的、通常看似随机的日常变化背景。在对流层，大风暴在内部发展，不需要外部强迫或区域边界条件的突然脉冲变化。虽然内部不稳定也在地球的电离层和热层中发挥作用（特别是在低纬度地区）；相反，热层的大部分天气是由来自上方和下方区域的外力直接驱动的。向上传播的波浪和潮汐对低水平的日常变化起着无处不在的作用，而太阳辐射、太阳风和地球磁层动力学的波动则驱动着广泛的热层扰动，并完全负责驱动风暴和其他大型事件。这个项目的主要目标是了解热层天气每天大大小小的波动的起源。两个最先进的测量热层风和温度的遥感仪器将部署在南极洲，在先前的研究表明，该纬度拥有最极端和最复杂的热层天气行为。虽然以前的工作已经在全球范围内测量了多年的热层风和温度，但在这些地磁纬度上，从来没有任何仪器能够达到由提议的全天成像设计所实现的经过验证的灵敏度、分辨率和关注范围。这些新型法布里-佩罗光谱仪的性能比在南极麦克默多和南极站的上一代仪器高出两个数量级以上，这将为地球极帽热层的流体动力学开辟革命性的新见解。该奖项将解决一些具体的悬而未决的航空研究问题：在穿越极帽的一般反太阳中性流中观察到的复杂的日常变化的主要来源是什么？是什么机制导致了观测到的和模拟的温度和极帽内的潮汐振幅之间的差异？从极光椭圆向极地传播的热层重力波是否会在极帽热层中沉积大量的热量和/或动量？南极热层温度的长期记录中是否有任何人为气候变化和/或太阳活动下降的迹象？前沿科学、国际合作以及前往南极洲的旅行为实现该计划的教育和推广目标提供了理想的机会。预计该项目将产生更广泛的影响，包括培养一名博士研究生，促进南极洲的国际科学协作与合作，并提供对卫星运营商、通信人员和导航员具有业务价值的实时和存档数据。

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.