GEM: The Role of Heavy Ion Outflow in Driving Sawtooth Oscillations

GEM：重离子流出在驱动锯齿振荡中的作用

• 批准号: 1502937
• 负责人: Lynn Kistler
• 金额: $ 13.93万
• 依托单位: University of New Hampshire
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2016
• 资助国家: 美国
• 起止时间: 2016-02-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1502937&HistoricalAwards=false
• 关键词: GEM; Role; Heavy; Ion; Outflow

The Geospace Environment Modeling (GEM) Program is a broad-based, community-initiated research program on the physics of the Earth's magnetosphere and the coupling of the magnetosphere to the atmosphere and to the solar wind. The work of GEM is accomplished in a series of campaigns and focus groups that solve specific problems leading to the construction of a global Geospace General Circulation Model (GGCM) with predictive capability. This project will contribute essential results to this goal pertaining to understanding a fundamental and mysterious mode of magnetic storms termed Sawtooth oscillations. Particularly, the project will investigate the potential role that heavy Oxygen ions escaping from the upper atmosphere may play in this. In addition, the project will support a graduate student participating in the research effort at University of New Hampshire. The specific goal of this investigation is to perform a superposed epoch analysis of ion outflow observed by the FAST spacecraft on the nightside during sawtooth events. The study will utilize a publicized database of 122 sawtooth events, comprising nearly 500 individual oscillations, which occurred during the FAST era (October 1996 to April 2009). About two thirds of these have coverage of the nightside aurora. This constitutes a sufficiently large set of events to allow for a comparison between the two main solar-wind drivers of Sawtooth events (SIR-driven and ICME-driven events, respectively) and to be able to compare these with the outflow from non-sawtooth events. Specifically, the superposed epoch analysis of the FAST data will be used to determine whether the observed outflow increases after each "tooth," driving the next tooth.

地球空间环境建模方案是一个基础广泛的社区发起的研究方案，研究地球磁层物理学以及磁层与大气层和太阳风的耦合。 全球地球观测系统的工作是通过一系列活动和重点小组来完成的，这些活动和小组解决了导致建立具有预测能力的全球地球空间大气环流模型的具体问题。这个项目将有助于这一目标的基本成果有关了解一个基本的和神秘的模式磁暴称为锯齿振荡。特别是，该项目将研究从高层大气中逃逸的重氧离子可能在其中发挥的潜在作用。此外，该项目将支持一名研究生参加新罕布什尔州大学的研究工作。这项研究的具体目标是对锯齿事件期间FAST航天器在夜侧观测到的离子流出进行叠加历元分析。 这项研究将利用一个公开的数据库，其中包括FAST时代（1996年10月至2009年4月）发生的122个振荡事件，包括近500个单独的振荡。其中大约三分之二的地区可以看到夜侧极光。这构成了一个足够大的事件集，可以比较锯齿事件的两个主要太阳风驱动因素（分别是SIR驱动事件和ICME驱动事件），并能够将其与非锯齿事件的流出进行比较。 具体而言，FAST数据的叠加历元分析将用于确定在每个“齿”之后观察到的流出是否增加，从而驱动下一个齿。