CEDAR: Dynamics of the Neutral Upper Atmosphere and Coupling to the Topside Ionosphere

这是一个为期5年的项目，目的是利用无源光学和非相干散射雷达技术，从观测上研究中性上部热层与外逸层、电离层和下部热层的动力学和化学耦合。 该项目建立在升级的仪器和先进的实验光学和红外技术的基础上，这些技术是在提议团队以前的CEDAR赠款下开发的。阿雷西博天文台的三台最近升级的法布里-珀罗干涉仪（FPI）将用于研究O，H，He的夜辉发射。主要的科学目标是使用三个高分辨率FPI测量中性温度和风来量化从低热层到外逸层的夜间中性传输。 同时ISR测量的离子密度，离子漂移，离子温度和电子温度在顶侧电离层也将获得。 这使得能够调查上部热层、外逸层和顶侧电离层中主要中性和离子物种之间的动态热耦合和化学耦合。 具体而言，三个FPI和两个光度计将在五年计划的每年四个新月期间以双辉模式运行，该计划将在下一个太阳活动最大期进行观测研究工作。其中两次活动安排在每年的秋季和冬季，第三次在春季，第四次在9月春分附近。 在此基础上，一些具体的突出的科学问题将得到解决，包括：1）是否有一个持久的人口热氧在上层热层和顶侧电离层？2)世纪后半叶对流层甲烷丰度的增加是否改变了大气顶部的成分？3)在热层和散逸层中中性风是如何随高度变化的？4)在F2峰值附近的垂直中性风的强度和半日行为是什么？该项目具有重大的广泛影响。 该项目将产生的测量结果和科学发现与空间气象和气候研究都有关。该项目将支持一名西班牙裔女科学家和另外两名女专业人员的早期职业发展，并将通过进一步发展阿雷西博天文台现有的仪器设备和与天文台人员的广泛合作，支持阿雷西博天文台的基础设施。

This is a 5-year project to investigate observationally the dynamic and chemical coupling of the neutral upper thermosphere to the exosphere, to the ionosphere, and to the lower thermosphere using passive optical and incoherent scatter radar (ISR) techniques. The project builds on upgraded instrumentation and advanced experimental optical and infrared techniques that were developed under the proposing team's previous CEDAR grant. Three recently upgraded Fabry-Perot Interferometers (FPIs) at Arecibo Observatory will be used to study nightglow emissions from O, H, He. The main science goal is to quantify the nighttime neutral transport from the lower thermosphere to the exosphere using the three high resolution FPIs to measure neutral temperatures and winds. Simultaneous ISR measurements of ion densities, ion drifts, ion temperatures, and electron temperature in the topside ionosphere will also be obtained. This allows for the investigation of the dynamic thermal and chemical coupling between the major neutral and ionic species in the upper thermosphere, exosphere and topside ionosphere. Specifically, the three FPIs and two photometers will be operated in campaign-mode, during four new moon periods each year of the five-year program, which carries this observational research effort through the next solar maximum. Two of these campaigns are scheduled in the fall and winter each year, a third in the spring, and a fourth near September equinox. Based on this, a number of specific outstanding science questions will be addressed, including: 1) Is there a persistent population of hot oxygen in the upper thermosphere and topside ionosphere? 2) Is the enhancement of tropospheric methane abundance during the second half of the 20th century altering the composition at the top of atmosphere? 3) How do neutral winds vary with altitude in the thermosphere and exosphere? 4) What is magnitude and semi-diurnal behavior of vertical neutral winds near the F2-peak? The project has significant broader impacts. The measurements and scientific findings that will result from the project are relevant both to space weather and climate research. The project will support the early career development of a Hispanic female scientist as well as two other female professionals and also will support the infrastructure at Arecibo Observatory through the further development of the current instrumentation there and through extensive collaboration with the observatory personnel.