A Study of the Long-term Trends in the US Mid-latitude Ionosphere from 1936-2009 by Extending the US Ionospheric Database Two Decades Prior to the 1957 IGY

该项目的目标是调查华盛顿，华盛顿特区附近中纬度电离层的长期行为，利用1936年至1957年获得的历史电离层探测仪测量数据，以便在1957年国际地球物理年（IGY）电离层观测普及之前将现有数据延长20多年。 档案数据目前储存在35毫米胶片上，这项工作的第一个目标是利用将为此项目开发的胶片扫描装置对记录进行扫描。 这些数据将使用调查人员以前开发的一种自动化程序，即电离层探测仪还原专家系统，转换成电离层状态参数（电子密度分布图）。 新的数据集将与现有的手比例电离图值数据库一起进行分析，手比例电离图值是从位于华盛顿，华盛顿特区（1957-1968年）和沃洛普斯岛（1967-2009年）附近的电离层探测仪获得的，以评估电离层参数的长期趋势。 趋势分析的一个具体科学重点是高层大气长期冷却的量化，这是高层大气学中的一个突出问题。 新的扩展数据集将提供给更广泛的社区。

This goal of this project is to investigate the long-term behavior of the mid-latitude ionosphere near Washington, D.C., using historical ionosonde measurements obtained from 1936 to 1957 in order to extend existing data by more than two decades prior to the 1957 International Geophysical Year (IGY), when ionospheric observation became widespread. The archival data is currently stored on 35 mm films, and the first goal of this effort is to digitize the records using a film scanning device to be developed for this project. The data will be converted into ionospheric state parameters (electron density profiles) using an automated procedure, the Expert System Ionosonde Reduction (ESIR), previously developed by the investigators. The new data set will be analyzed in conjunction with an existing database of hand-scaled ionogram values, obtained from an ionosonde located near Washington, D.C. (1957-1968) and Wallops Island (1967-2009), in order to assess long-term trends in the ionospheric parameters. A specific scientific focus of the trend analysis is the quantification of secular cooling of the upper atmosphere, an outstanding question in aeronomy. The new, extended dataset will be made available to the wider community.