Postdoctoral Fellowship: OPP-PRF: Investigating Polar Geomagnetic Signatures Associated with Substorm Onset to Address Data Gaps in Southern Hemisphere Space Weather Research

博士后奖学金：OPP-PRF：研究与亚暴爆发相关的极地地磁特征，以解决南半球空间天气研究中的数据差距

• 批准号: 2317994
• 负责人: Michelle Salzano
• 金额: $ 32.46万
• 依托单位: SPACE SCIENCE INSTITUTE
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-01 至 2025-08-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2317994&HistoricalAwards=false
• 关键词: Postdoctoral; Fellowship; OPP; PRF; Investigating

Space is often considered a vacuum, but it is home of various electromagnetic fields and charged particles called plasma. Variations in these fields and plasma can be called “space weather”, and these space weather events may severely impact various human-deployed technological networks in several ways, including interfering with GPS technologies and causing vast electric power blackouts. Geomagnetic substorms in polar regions are daily space weather events and these are typically identified and studied using Auroral Electrojet (AE) indices, which are compiled using ground-based geomagnetic field variation measurements. However, while AE indices exist in the Northern Hemisphere, there are no such indices developed for the Southern Hemisphere. There simply is not enough land to have appropriately placed and spaced geomagnetic instruments. However, this is important because there are interhemispheric asymmetries between the northern and southern polar regions. In other words, the two hemispheres are not identical, so it cannot be assumed that substorm observations from the northern auroral zone are compatible with research done in the southern polar areas. As the interhemispheric asymmetries in substorm research are also not often able to be evaluated, this award will be addressing the southern polar regions’ data gap by investigating potential alternate methods to identify southern polar substorms. The Pi1B waves are a type of natural Ultra Low Frequency (ULF) waves characterized by broadband bursts in the Pi1 range (1 – 40 second periods). Substorm onsets are well correlated with Pi1B waves in the evening to post-midnight sectors, and it was suggested in the geospace literature that Pi1B waves could be used to monitor polar substorms development. This award will use a mix of existing, publicly available ground-based magnetometer data and in-situ satellite measurements to identify and compare both the substorm onsets and Pi1B waves. This research will address the following outstanding science questions: (1) Are Pi1B waves a proxy for Auroral Electrojet intensification associated with substorm onset; (2) If so, how does the Pi1B proxy compare with existing proxies based on the AE and other geomagnetic indices; and (3) What are physical mechanisms that can explain connections between the Pi1B waves and substorm onsets.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

太空通常被认为是真空的，但它是各种电磁场和被称为等离子体的带电粒子的家园。这些磁场和等离子体的变化可以被称为“空间天气”，这些空间天气事件可能以几种方式严重影响各种人类部署的技术网络，包括干扰GPS技术和造成大规模停电。极地的地磁亚暴是日常的空间天气事件，通常使用极光电喷流（AE）指数进行识别和研究，这些指数是利用地面地磁场变化测量编制的。然而，虽然北半球存在声发射指数，但南半球没有这样的指数。根本没有足够的土地来适当地放置和间隔地磁仪器。然而，这很重要，因为南北两极地区之间存在半球间不对称。换句话说，两个半球是不相同的，因此不能假设从北半球极光区观测到的亚暴与在南极地区所做的研究是一致的。由于亚暴研究中的半球间不对称性通常也无法评估，该奖项将通过研究识别南极亚暴的潜在替代方法来解决南极地区的数据缺口。Pi1B波是一种天然的超低频（ULF）波，其特征是在Pi1范围内（1 - 40秒周期）的宽带爆发。亚暴的发生与Pi1B波在傍晚至午夜后的时段有很好的相关性，并且在地球空间文献中提出，Pi1B波可以用来监测极地亚暴的发展。该合同将使用现有的、公开的地面磁力计数据和原位卫星测量数据来识别和比较亚暴的爆发和Pi1B波。本研究将解决以下突出的科学问题：(1)Pi1B波是否代表与亚暴发生相关的极光电喷强化；(2)如果是，Pi1B波与基于声发射和其他地磁指标的现有代理相比如何；(3)Pi1B波与亚暴发生之间的联系有什么物理机制可以解释。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。