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

这是一个为期5年的项目，旨在利用被动光学和非相干散射雷达（ISR）技术，对中性上层热层与外逸层、电离层和下层热层的动力学和化学耦合进行观测研究。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之前的CEDAR资助下开发的。阿雷西博天文台的三个最近升级的法布里-珀罗干涉仪（fpi）将用于研究O， H， He的夜光发射。主要的科学目标是量化夜间从低层热层到外逸层的中性输送，使用三个高分辨率fpi来测量中性温度和风。同时ISR测量离子密度、离子漂移、离子温度和上层电离层的电子温度也将获得。这允许研究上层热层、外逸层和上层电离层中主要中性和离子物种之间的动态热和化学耦合。具体来说，三个fpi和两个光度计将在五年计划中每年四个新月期间以运动模式运行，该计划将在下一个太阳活动极大期进行观测研究。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)在上层热层和上层电离层是否存在持续的热氧种群？2) 20世纪下半叶对流层甲烷丰度的增加是否改变了大气顶部的组成？3)在热层和外逸层中，中性风如何随高度变化？4) f2峰附近垂直中性风的量级和半日变化特征是什么？该项目具有重大的广泛影响。该项目将产生的测量和科学发现与空间天气和气候研究有关。该项目将支持一名西班牙女科学家和另外两名女性专业人员的早期职业发展，并将通过进一步发展那里现有的仪器和通过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.