GEM: A Survey of Simultaneous Pc 3 Micropulsations and High Latitude Impulsive Events for the GEM Boundary Layer Campaign

GEM：GEM 边界层运动的同步 Pc 3 微脉冲和高纬度脉冲事件调查

• 批准号: 9623790
• 负责人: Edgar Bering
• 金额: $ 15万
• 依托单位: University of Houston
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1996
• 资助国家: 美国
• 起止时间: 1996-07-15 至 2000-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9623790&HistoricalAwards=false
• 关键词: GEM; Survey; Simultaneous; Pc; Micropulsations

This project will undertake analysis of data to increase our understanding of the possible signatures of magnetopause and magnetospheric boundary layer processes that are observed in the ionosphere and on the ground. The study will focus specifically on a search for simultaneous observations of two different geomagnetic perturbation phenomena whose possible sources may be either the magnetopause or the upstream solar wind. The phenomena that will be studied are Pc 3 micropulsations and high latitude magnetic impulse events known as traveling convection vortices (TCVs). Pc 3 micropulsations are quasi-periodic pertubations of the Earth's magnetic field with periods between 10 and 45 seconds. One sources of these pulsations is believed to be the upstream solarwind. High latitude magnetic impulse events are large amplitude (100nt), often monopolar pulsations of the geomagnetic field with periods of 10 - 20 minute duration. Interest in these pulsations was stimulated by the hypothesis that they consituted the ionospheric signature of sporatic reconnection -- though this speculation has become very controversial. Recent work suggests that these may occur on closed field lines. The possible connection between Pc 3 and TCVs has not been undertaken. There have, however, been some observations to indicate that Pc 3 events can occur simultaneously with TCV events and propagate with the same horizontal speed. This suggests that they may occur on the same field lines and share a common source. A detailed study is needed to develop a conclusive determination of a possible relationship between the two phenomena. This will be accomplished using data from the MACCS magnetometer array in northern Canada.

该项目将对数据进行分析，以增进我们对在电离层和地面上观测到的磁层顶和磁层边界层过程的可能特征的了解。这项研究将特别侧重于同时观测两种不同的地磁扰动现象，其可能的来源可能是磁层顶或上游太阳风。将研究的现象是Pc3微脉动和被称为移动对流涡旋(TCV)的高纬度磁脉冲事件。PC3微脉动是地球磁场的准周期扰动，周期在10秒到45秒之间。这些脉动的来源之一被认为是上游的太阳风。高纬磁脉冲事件是一种幅度很大(100毫微秒)的地磁场单极脉动，周期为10-20分钟。人们对这些脉动的兴趣是由这样一种假设激发的，即它们构成了电离层零星重新连接的特征--尽管这种猜测已经变得非常有争议。最近的研究表明，这些现象可能发生在封闭的场线上。Pc3和TCV之间可能的联系还没有进行。然而，已经有一些观测表明，Pc3事件可以与Tcv事件同时发生，并以相同的水平速度传播。这表明它们可能发生在相同的场线上，并且共享一个共同的来源。需要进行详细的研究，以确定这两种现象之间可能存在的关系。这将使用来自加拿大北部MACCS磁力计阵列的数据来完成。