CEDAR: The Role of Neutral Winds in the Day-to-day Variability of the Ionospheric Mid-Latitude Evening Anomalies

CEDAR：中性风在电离层中纬度夜间异常的日常变化中的作用

• 批准号: 1651461
• 负责人: Ludger Scherliess
• 金额: $ 16.24万
• 依托单位: Utah State University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-09-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1651461&HistoricalAwards=false
• 关键词: CEDAR; Role; Neutral; Winds; Day

The Weddell Sea Anomaly (WSA) is a recurrent feature of the Southern hemisphere summertime midlatitude to high-latitude ionosphere. Electron densities maximize around the Weddell Sea region during the night, rather than during the day as would be expected due to photoionization by the Sun. The objective of the work is to understand the causes of these evening anomalies, with particular attention to the roles of thermospheric neutral winds, and waves originating from the lower atmosphere. Because winds are not directly sensed in this part of the atmosphere, they must be inferred from other available measurements such as electron density. A key value of the research is the generation and dissemination of observation-driven global-scale ionospheric winds computed from the PI's state of the art model.The WSA can be thought of as testbed for coupled ionosphere/thermosphere modeling capabilities. The primary research tool is USU's Thermospheric Wind Assimilation Model (TWAM) that will be coupled to an ionospheric assimilation system (GAIM). These two systems ingest data from a comprehensive set of ground-based and space-based data networks. They will enable investigation of the wind response to day-to-day variations in ionospheric drivers inside and outside the anomaly regions. This proposal is very well-aligned with the goals of the most recent Decadal Survey, which charges the thermospheric modeling and data assimilation communities with providing winds in data-absent regions.

威德尔海异常（WSA）是南半球夏季中纬度至高纬度电离层反复出现的特征。威德尔海地区的电子密度在夜间达到最大，而不是像预期的那样在白天，因为太阳的光电离作用。这项工作的目的是了解这些夜间异常的原因，特别关注热层中性风和源自低层大气的波浪的作用。由于在这部分大气中无法直接感知到风，因此必须从其他可用的测量值（例如电子密度）来推断风。该研究的一个关键价值是根据 PI 最先进的模型计算出观测驱动的全球范围电离层风的生成和传播。WSA 可以被视为电离层/热层耦合建模能力的测试平台。主要研究工具是 USU 的热层风同化模型 (TWAM)，该模型将与电离层同化系统 (GAIM) 耦合。这两个系统从一套全面的地基和天基数据网络中获取数据。它们将能够调查风对异常区域内外电离层驱动因素日常变化的响应。该提案与最近十年调查的目标非常一致，该调查要求热层建模和数据同化界在缺乏数据的地区提供风。