CEDAR: All-Sky Mapping of E-Region Neutral Winds Above Poker Flat, Alaska

CEDAR：阿拉斯加 Poker Flat 上空 E 区中性风的全天空测绘

• 批准号: 0737618
• 负责人: Mark Conde
• 金额: $ 19.74万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-01-01 至 2009-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0737618&HistoricalAwards=false
• 关键词: CEDAR; Sky; Mapping; Region; Neutral

This project will use ground-based optical remote sensing to obtain two-dimensional spatially resolved maps of horizontal neutral winds in Earth's night-time auroral E-region. The maps will be derived from Doppler shifts of the atomic oxygen auroral emission line at 557.7 nm. While several other ground and spaced-based techniques exist for measuring E-region winds, they are all difficult, and they do not duplicate the coverage and resolution that is anticipated in this project. The wind maps will cover a geographic region approximately 700 km in diameter, centered on Poker Flat, Alaska. This fully includes the E-region field of view of the National Science Foundation's new AMISR radar. Vertical coverage will span approximately 110 km to 140 km. With the mapping region resolved into 60 to 100 sub-fields, integration times for a single map will vary between one and five minutes, depending on signal levels, for typical uncertainties of a few meters per second. Doppler temperature maps will also be obtained with the same spatial and temporal resolution, with typical uncertainties of less than 10K. A number of scientific studies will be conducted. All depend on combining E-region wind maps with data from other instruments monitoring the same field of view, including the Poker Flat AMISR radar. Topics to be studied include the role of ion-neutral momentum coupling in E-region neutral dynamics at small ( 100 km) spatial scales, the role of horizontal transport in the evolution of storm-induced thermospheric composition perturbations, horizontal velocity perturbations due to gravity waves, the role of neutral winds in determining the partitioning of magnetospheric energy deposition between heating and bulk motion of the neutral atmosphere, and the relationship between horizontal divergence and vertical wind in the E- and F-regions. The project includes work to significantly upgrade the instrument's self-calibration capability with a 5-color helium neon laser, a new frequency stabilized laser, and an automated calibration source viewing system. In addition to CEDAR-specific science topics, a number of broader impacts are anticipated. A graduate student will be supported to participate in this research, whose work will be integral to all aspects of the project. With a major emphasis on optical calibration, this project has obvious relevance to the University of Alaska's 400-level undergraduate optics class - which is required for all physics majors. Aspects of both the optical design and the resulting calibration data will be incorporated into the students' laboratory and homework projects. The E-region wind mapping would add to the infrastructure of atmospheric science at a general level by demonstrating a new capability that other experimenters could exploit according to their research needs. More specifically, there is a high degree of synergy with two major existing NSF funded projects at Poker Flat: The AMISR radar and a tristatic array of three narrow-field Fabry-Perot spectrometers.

该项目将利用地面光学遥感获得地球夜间极光E区水平中性风的二维空间分辨率地图。这些地图将根据原子氧极光发射线在557.7 nm处的多普勒频移得出。虽然还有其他几种地面和空基技术用于测量E区风，但它们都很困难，而且它们不能复制本项目预期的覆盖范围和分辨率。风图将覆盖直径约700公里的地理区域，中心位于阿拉斯加的扑克平地。这完全包括国家科学基金会新的阿米西里雷达的E区视场。垂直覆盖范围约为110至140公里。由于测绘区域被分解成60到100个子区域，对于几米/秒的典型不确定度，单个测绘的积分时间将根据信号电平在1到5分钟之间变化。还将以相同的空间和时间分辨率获得多普勒温度图，典型的不确定度小于10K。将进行多项科学研究。所有这些都依赖于将E区风图与监测相同视场的其他仪器的数据结合起来，包括Poker Flat阿米西里雷达。将研究的主题包括：在小(100公里)空间尺度上离子-中性动量耦合在E区中性动力学中的作用；水平输送在风暴引起的热层组成扰动演变中的作用；重力波引起的水平速度扰动；中性风在确定磁层能量沉积在加热和中性大气整体运动之间的分配方面的作用；以及E区和F区水平发散与垂直风之间的关系。该项目包括显著升级仪器的自校准能力，使用5色氦-霓虹激光器、新的稳频激光器和自动校准源查看系统。除了雪松特有的科学主题外，预计还会产生一些更广泛的影响。将支持一名研究生参与这项研究，其工作将是该项目所有方面不可或缺的一部分。由于重点是光学校准，这个项目与阿拉斯加大学400级本科光学课程有明显的相关性--这是所有物理专业的必修课。光学设计和由此产生的校准数据的各个方面都将被纳入学生的实验室和家庭作业项目。E区风图将通过展示一种其他实验者可以根据其研究需要开发的新能力，在一般层面上增加大气科学的基础设施。更具体地说，在Poker Flat，现有的两个由NSF资助的主要项目高度协同：阿米西里雷达和由三个窄场法布里-珀罗光谱仪组成的三站阵列。