Fabry-Perot Studies of Equatorial Thermospheric Dynamics and Composition

在这个项目中，需要资金，以便利用在磁赤道以南约400公里的阿雷基帕运行的升级的自动阿雷基帕法布里-佩罗涉仪(法布里-佩罗涉仪)继续研究赤道热层动力学。通过用背面变薄的CCD探测器取代GaAs光电倍增器，实现了将FPI灵敏度提高15倍的仪器升级。阿雷基帕浮标灵敏度的提高将用于扩展目前对午夜最高温度和赤道风和温度异常(EWTA)的研究，以提高精度。提出了一条新的研究路线，该路线将基于对O+和OH气辉发射的观测来研究热层[O]。O+光谱特征的多普勒宽度将提供有关以前在1980年使用该技术观测到的热氧冕的可能产生的信息。如果这种热[O]原子存在于赤道高层热层和外基附近，除了有效多普勒宽度增加到相当于约4000℃外，应该可以看到相对于早期太阳压倒角观测归一化的翻转预测，732 nm发射率的几个瑞利。所提出的732 nm测量结果可能解决是否存在快速氧离子从磁层流入赤道电离层的问题，这被认为是由于极地O+流出通过磁层-电离层耦合过程转移到低纬电离层造成的。在夜间，将观测到731.6 nm处的OH夜辉的多普勒频移，以确定质心高度约87公里的OH体积发射剖面上的平均中层风。这些结果将特别有助于支持定时(热层、电离层、中间层、能量学和动力学)卫星潮汐研究，因为南半球对中层潮汐风的地面观测很少。滤光片更改器将根据需要在630 nm和732 nm两种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。

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.