CEDAR: High-resolution Multistatic Mapping of Small-Scale Flow Structures in Earth's Auroral Thermosphere

该项目将测量地球上约250公里高空的风。S极光热层。对这些风的了解仍然很少，特别是在100公里或更小的空间尺度上。该项目基于这样一个假设，即水平长度尺度为~100公里或更短的漩涡和波浪是地球动力学的重要贡献者。它们的累积影响对于热层的基本物理和空间天气的业务预测都是重要的。为了确定小尺度的气流结构，目前位于阿拉斯加的所有7台Fabry-Perot光谱仪将被配置为同时将注意力集中在一个与PFISR雷达视野大致一致的小地理区域上。这些仪器将同时监测热层温度和风矢量，生成二维温度图和风矢量图，空间分辨率约为80公里。该阵列将以这种模式运行三次，每次持续约两个月。为了量化小尺度涡旋和波浪在热层中的重要性，该项目将解决三个重点科学问题：(1)阿拉斯加小尺度涡旋和波浪的发生频率、强度、光谱分布和总体形态是什么？S极光热层，在安静和活跃的条件下？(2)是否有可能根据这些小尺度地物相对于其他测量的发生时间、它们相锋的空间排列以及它们的方向来确定这些小尺度地物的驱动机制和源区域？传播?(3)是否有可能根据温度和三分量风扰动的振幅、周期、水平和垂直波长以及这些量的时间演变来估计这些波的动量通量和耗散率？该项目将包括培训一名研究生，加强阿拉斯加图里克湖的研究设施，支持Poker Flat的火箭任务，并将尖端科学研究带到偏远的阿拉斯加村庄。

This project will measure winds at ~250 km altitude in Earth?s auroral thermosphere. These winds remain poorly understood, especially at spatial scales spanning ~100 km or less. The project is based on the hypothesis that eddies and waves at horizontal length scales of ~100 km or less are important contributors to the dynamics of Earth?s auroral thermosphere and that their cumulative impact is important both for the basic physics of the thermosphere and for operational prediction of space weather. To determine small-scale flow structures, all seven of the Fabry-Perot spectrometers now in Alaska will be configured to focus their attention simultaneously onto one small geographic region roughly coinciding with the field of view of the PFISR radar. These instruments will simultaneously monitor thermospheric temperatures and wind vectors, producing two-dimensional maps of temperatures and 3-component vector winds, with a spatial resolution of around 80 km. The array will operate in this mode for three campaigns each lasting around two-months. To quantify the importance of small-scale eddies and waves in the thermosphere, the project will address three focused science questions: (1) What is the occurrence frequency, intensity, spectral distribution, and overall morphology of the small-scale eddies and waves in Alaska?s auroral thermosphere, for both quiet and active conditions? (2) Is it possible to identify the driver mechanisms and source regions for these small-scale features, based on timing of their occurrence relative to other measurements, the spatial alignment of their phase fronts, and the directions in which they?re propagating? (3) Is it possible to estimate the momentum flux and dissipation rates of these waves, based on the amplitudes, periods, and horizontal & vertical wavelengths of the temperature and 3-component wind perturbations, and on the time evolution of these quantities? This project will include training one graduate student, enhancing the research facility at Toolik Lake in Alaska, supporting rocket missions from Poker Flat, and bringing cutting-edge scientific research to remote Alaskan villages.