Fabry-Perot Studies of Equatorial Thermospheric Dynamics and Composition

赤道热层动力学和成分的法布里-珀罗研究

• 批准号: 0132600
• 负责人: John Meriwether
• 金额: $ 24.25万
• 依托单位: Clemson University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2002
• 资助国家: 美国
• 起止时间: 2002-03-01 至 2006-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0132600&HistoricalAwards=false
• 关键词: Fabry; Perot; Studies; Equatorial; Thermospheric

In this project funds are requested to continue studies of the equatorial thermospheric dynamics using the upgraded automated Arequipa Fabry-Perot interferometer (FPI) observatory operating at Arequipa which is ~400km south of the magnetic equator. The instrumental upgrade increase of the FPI sensitivity by a factor of 15 is achieved by replacing the GaAs photomultipler with a back-thinned CCD detector. The improved sensitivity of the Arequipa FPI will be used to extend current studies of the midnight temperature maximum and the equatorial wind and temperature anomaly (EWTA) with increased accuracy. A new line of research is proposed that would be based upon the observations of O+ and OH airglow emissions for the study of thermospheric [O]. The Doppler widths of the O+ spectral feature would provide information regarding the possible production of the hot oxygen corona that was previously observed with this technique in 1980.If such hot [O] atoms exist near the equatorial upper thermosphere and exobase, aside from an increase in the effective Doppler width to equivalent temperatures of ~4000, an excess of a few Rayleighs of 732nm emission rate relative to the FLIP predictions normalized by the observations at earlier solar depression angles should be seen. The proposed 732 nm measurements may resolve the question as to whether there exists and influx of fast oxygen ions into the equatorial ionosphere from the magnetosphere, which has been suggested to be caused by the polar O+ outflow that is diverted to the low latitude ionosphere by magnetospheric-ionospheric coupling processes.During the night the Doppler shifts of the OH nightglow at 731.6 nm would be observed to determine mesospheric winds averaged over the OH volume emission profile with a centroid altitude of ~87km. These results would be particularly useful in the support of the TIMED (thermosphere ionosphere mesosphere energetics and dynamics) satellite tidal studies as ground-based observations of mesospheric tidal winds in the Southern hemisphere are sparse. A filter changer would select between the two filters, 630 nm and 732 nm, as necessary to get the observations these science objectives require.

在该项目中，需要资金继续研究赤道热层动力学，使用升级后的自动化阿雷基帕法布里-珀罗干涉仪（FPI）天文台，该天文台位于磁赤道以南约 400 公里的阿雷基帕。 通过用背照式 CCD 探测器取代 GaAs 光电倍增器，FPI 灵敏度的仪器升级提高了 15 倍。 阿雷基帕 FPI 灵敏度的提高将用于扩展当前对午夜最高温度以及赤道风和温度异常 (EWTA) 的研究，并提高准确性。 提出了一条新的研究路线，该路线将基于 O+ 和 OH 气辉排放的观测，用于热层 [O] 的研究。 O+ 光谱特征的多普勒宽度将提供有关 1980 年使用该技术观察到的热氧日冕的可能产生的信息。如果这样的热 [O] 原子存在于赤道上层热层和外基底附近，除了增加在等效温度约 4000 的有效多普勒宽度中，相对于通过早期太阳俯角观测标准化的 FLIP 预测，732nm 发射率的一些瑞利的过量应该被看到。 所提出的 732 nm 测量可以解决以下问题：是否存在快速氧离子并从磁层流入赤道电离层，这被认为是由磁层转移到低纬度电离层的极地 O+ 流出引起的。 -电离层耦合过程。在夜间，将观测 731.6 nm 处 OH 夜光的多普勒频移，以确定中层风OH体积排放剖面的平均值，质心高度约为87公里。 这些结果对于支持 TIMED（热层、电离层、中间层能量学和动力学）卫星潮汐研究特别有用，因为对南半球中层潮汐风的地面观测很少。 滤光片更换器可以根据需要在 630 nm 和 732 nm 这两个滤光片之间进行选择，以获得这些科学目标所需的观测结果。