Collaborative Research: Continued Study of Ultra Low Frequency (ULF) Waves at Cusp Latitudes on Svalbard to Probe Earth's Space Environment

合作研究：继续研究斯瓦尔巴特群岛尖纬度的超低频（ULF）波，以探测地球的空间环境

• 批准号: 1202267
• 负责人: Mark Engebretson
• 金额: $ 18.59万
• 依托单位: Augsburg University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2013
• 资助国家: 美国
• 起止时间: 2013-08-01 至 2016-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1202267&HistoricalAwards=false
• 关键词: Collaborative; Research; Continued; Study; Ultra

A large array of ground based instruments has been installed on the Svalbard archipelago in Norway. Svalbard is frequently on polar cusp field lines that map to the outer boundary of the Earth's magnetosphere where it interacts with the solar wind and interplanetary magnetic field (IMF). This proposal has two parts: One part is for support for the continued operation of and processing data from an array of four search coil magnetometers (induction antennas). The second part is to carry out analysis of data from these four instruments. Svalbard is the only place in the northern hemisphere where polar cusp field lines can be observed for extended periods in darkness at noon. In addition to the four search coil magnetometers auroral imagers and photometers, several radars (EISCAT, SPEAR and SuperDarn) and the northernmost fluxgate magnetometers of the IMAGE chain are located on Svalbard. This makes Svalbard an excellent place to carry out observations of ionospheric phenomena on magnetic field lines that map to the magnetopause. Three main types of studies using the data from the search coils and other instruments are:a.) Make a concentrated effort to understand the observations of Pc 1-2 waves in the cusp and their effect on radiation belt dynamics. In the Pc 1-2 frequency range electromagnetic ion cyclotron waves (EMIC) are thought to interact resonantly with MeV electrons in the radiation belts. The waves and radiation belt dynamics and the persistence of waves (sometimes seen for days) will be studied as well as waves associated with auroral precipitation. b.) Probe the Ionosphere Alfvén Resonator (IAR) by using the Space Plasma Exploration by Active Radar (SPEAR) heater facility in conjunction with the EISCAT radar. The IAR is a region in the ionosphere bounded by the F or E region at lower altitudes and by a peak in the Alfvén velocity at higher altitudes. This research will characterize the quality factor (Q) of the IAR. The quality factor relates the energy stored in the resonator with the energy dissipated. If the IAR is driven long enough the energy contained in the resonator will be proportional to Q. By controlling the input energy from the SPEAR heater they will be able to determine Q. c.) Investigate the properties of PC3-4 waves at very high latitudes. In this study SuperDARN radar will be used along with the search coils to determine the intensity of PC 3-4 as a function of position with respect to the cusp. The goal will be to determine how these ULF waves reach the high latitude ionosphere. The data from the four closely space magnetometers are very valuable for a number of space physics studies. The team will make the data available to the scientific community through the NASA Virtual Observatories. This proposal will support a graduate student at the University of New Hampshire and an undergraduate researcher at Augsburg College.

挪威斯瓦尔巴群岛上安装了大量地面仪器，斯瓦尔巴群岛经常位于极地尖端磁力线上，这些磁力线映射到地球磁层的外边界，在那里与太阳风和行星际磁场（IMF）相互作用。该提案分为两部分：一部分是支持四个搜索线圈磁力计（感应天线）阵列的持续操作和数据处理，第二部分是对这四个搜索线圈磁力计的数据进行分析。斯瓦尔巴群岛是北半球唯一可以在中午长时间观测极尖场线的地方。除了四个搜索线圈磁力计、极光成像仪和光度计外，还有多个雷达（EISCAT、SPEAR 和 SuperDarn）。 IMAGE 链最北端的磁通门磁力计位于斯瓦尔巴群岛，这使得斯瓦尔巴群岛成为对绘制的磁场线进行电离层现象观测的绝佳场所。使用搜索线圈和其他仪器的数据进行的三种主要研究是：a.) 集中精力了解尖点中 Pc 1-2 波的观测结果及其对辐射带动力学的影响。 Pc 1-2 频率范围电磁离子回旋波 (EMIC) 被认为与辐射带中的 MeV 电子发生共振，波和辐射带动力学以及波的持续性（有时会持续数天）。 b.) 使用主动雷达空间等离子体探测 (SPEAR) 加热器设施与 EISCAT 雷达一起探测电离层阿尔芬谐振器 (IAR)。电离层在较低海拔处以 F 或 E 区域为界，在较高海拔处以阿尔文速度峰值为界。这项研究将表征 IAR 的品质因数 (Q)。品质因数将谐振器中存储的能量与耗散的能量联系起来。如果 IAR 驱动足够长的时间，谐振器中包含的能量将与 Q 成正比。通过控制 SPEAR 加热器的输入能量，他们将能够确定 Q。 c.) 研究非常高纬度的 PC3-4 波的特性 在这项研究中，SuperDARN 雷达将与搜索线圈​​一起使用，以确定 PC 3-4 的强度作为相对于位置的函数。目标是确定这些超低频波如何到达高纬度电离层。来自四个近距离空间磁力计的数据对于许多空间物理研究非常有价值。该提案将为新罕布什尔大学的一名研究生和奥格斯堡学院的一名本科生研究员提供支持。