A Conjugate Study of ULF Waves at the Cusp: A GEM Project

尖端 ULF 波的共轭研究：GEM 项目

• 批准号: 9213361
• 负责人: John Olson
• 金额: $ 13.15万
• 依托单位: University of Alaska Fairbanks Campus
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-09-01 至 1995-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9213361&HistoricalAwards=false
• 关键词: Conjugate; Study; ULF; Waves; Cusp

This is a proposal to study the ULF wave spectrum at cusp stations in conjugate hemispheres. An auroral observatory located at Longyearbyen, Svalbard in the northern hemisphere has been in operation for nearly a decade and is equipped with induction coil and fluxgate magnetometers to measure the ULF wave spectrum. The station is also instrumented with all-sky and meridian scanning photometers which provide an optical context for the magnetic measurements. In the southern hemisphere, the Australian station at Davis, Antarctica is also equipped with induction coil and fluxgate magnetometers and has made observations of the ULF wave spectrum associated with the cusp for several year. We have begun an echange of data and the analysis shows promising correlations. It is well known that the cusp region is a rich source of ULF waves spanning the frequency spectrum from near dc to above Hz. The spectrum consists of an ensemble of waves and variations with causes ranging from boundary motions and macroscopic boundary instabilities at the low frequency end, through impulsive and coherent signals with correlation to the solar wind at intermediate frequencies, up to an beyond ion-cyclotron waves generated in the unstable plasma near the magnetospheric boundary layers and shocked cusp plasma. Our work in this analysis is aided by through collaboration with the plasma simulation group at the Geophysical Institute. Our goal is to collect ULF data at the two sites on a campaign basis in order to: o investigate the conjugacy of the cusp at these sites; o identify wave generation mechanisms associated with the cusp; o inspect the ULF spectrum at the two sites for correlations; o identify signatures of flux transfer and particle injection at the magnetopause; o use the waves as a diagnostic for location of the boundaries.

这是一个研究尖点处超低频波谱的建议 在共轭半球的站点。 极光观测站 位于北方斯瓦尔巴群岛的朗伊尔城， 已经运行了近十年，并配备了 感应线圈和磁通门磁力计测量超低频波 江西篇章 该站还配备了全天空和 提供光学背景的子午线扫描光度计 用于磁性测量。 在南半球， 位于南极洲戴维斯的澳大利亚站还配备了 感应线圈和磁通门磁力计， 与尖点有关的超低频波谱的观测 好几年了 我们已经开始改变数据， 分析显示了有希望的相关性。 众所周知，尖点区是一个丰富的超低频源 波跨越从近直流到高于赫兹的频谱。 光谱由波和变化的集合组成， 边界运动和宏观边界 低频端的不稳定性，通过脉冲和 与太阳风相关的相干信号. 中频，超过离子回旋波 产生于磁层边界附近的不稳定等离子体中 层和冲击尖端等离子体。 我们在这项分析中的工作是 通过与等离子体模拟小组的合作， 在地球物理研究所 我们的目标是在一个活动的两个站点收集ULF数据 基础，以便： O 研究这些部位尖瓣的共轭性; O 识别与 尖点; O 检查两个地点的超低频频谱的相关性; O 确定通量转移和粒子注入特征 在磁层顶 O 使用波作为诊断的位置， 边界