Fabry-Perot Studies of Equatorial Thermospheric Dynamics and Composition, Part II

调查人员将在秘鲁的阿雷基帕用改进的成像法布里-珀罗干涉仪测量热层风和温度。 近年来的空气力学研究已经确定赤道热层-电离层系统是一个高度结构化的环境，其中离子-中性耦合在发生的物理过程中起着至关重要的作用。 了解热层中性风场和温度场对于更好地了解这些过程如何运作至关重要。 阿雷基帕法布里-珀罗干涉仪（FPI）已经运行了二十年。 最近，该仪器进行了升级，与以前的观测相比，风和温度的精度提高了五倍。 这项研究工作包括对732纳米氧离子发射率进行曙暮光光谱剖面测量，以确定低纬度的热层原子氧密度。 一种新的操作模式将允许确定中性风场的散度和涡度。 发散测量将提供平均垂直风的估计，其精度被认为比直接测量提供的精度高10倍。 这些测量对于更好地了解午夜最高温度非常重要，午夜最高温度是低纬度地区午夜附近空气会聚和下降所产生的夜间赤道热层的一个重要特征。 另外两个科学目标是利用双基地FPI观测站在阿雷基帕和万卡约之间的共同空间内进行热层重力波观测。 这些结果将允许通过搜索纬向风和纬向风分量以及热层温度的同时波动来检查热层重力波的频率。阿雷基帕和万卡约FPI仪器的科学目标由于这两个仪器共同工作并与希卡马卡射电天文台合作开展协调和协同活动而大大增强。 克莱姆森物理本科生和研究生以及秘鲁学生将接触到实际的技术问题，这将扩大他们的经验，并将他们介绍给光学技术前沿的研究实践。 将获得无人值守的FPI在远程站点运行的宝贵经验，这将有助于未来扩大全球FPI观测站网络，这是空间气象预报应用的一个非常理想的目标。

The investigators will make measurements of thermospheric winds and temperatures with an improved imaging Fabry-Perot Interferometer at Arequipa, Peru. Aeronomic research in recent years has determined the equatorial thermosphere-ionosphere system to be a highly-structured environment in which the ion-neutral coupling plays a crucial role in the physical processes that occur. Knowledge of the thermospheric neutral wind and temperature fields is essential to the improved understanding of how these processes function. The Arequipa Fabry-Perot interferometer (FPI) has been operating for two decades. Recently, this instrument was upgraded to get a five-fold increase in wind and temperature precision as compared with previous observations. Included in this research effort are twilight spectral profile measurements of the 732 nm oxygen ion emission rate to determine the thermospheric atomic oxygen density at low-latitudes. A new operating mode will allow the determination of the divergence and vorticity of the neutral wind field. The divergence measurement would provide an estimate of the mean vertical wind with a precision believed to be ten times better than that provided by direct measurements. These measurements are important for achieving an improved understanding of the Midnight Temperature Maximum (MTM), which is a significant feature of the nighttime equatorial thermosphere created by the convergence and downwelling of air near midnight at low latitudes. Two additional science objectives would be to achieve thermospheric gravity wave observations within a common volume between Arequipa and Huancayo with a bistatic FPI observatory. These results would allow for the examination of the frequency of thermospheric gravity waves by searching for simultaneous fluctuations in zonal and meridional wind components as well as thermospheric temperature. The science objectives of the Arequipa and Huancayo FPI instruments are significantly enhanced by the coordinated and synergistic activity of both instruments working together and with the Jicamarca Radio Observatory. Clemson Physics undergraduate and graduate students as well as Peruvian students would be exposed to technical problems of a practical nature that will broaden their experience and introduce them to the practice of research at the cutting edge of optical technology. Valuable experience in the operations of unattended FPIs at remote sites would be gained that would assist future expansion of the global FPI observatory network, a highly desirable goal for space weather forecasting applications.