Conjugate Studies of ULF Waves and Magnetospheric Dynamics Using Ground-Based Induction Magnetometers at Four High-Latitude Manned Sites

自太空时代开始以来，人们为探索和了解地球的空间环境作出了越来越复杂的努力。科学家们现在对电离层和它上面的磁层的结构了解得很多，但是在我们完全了解从快速变化的太阳风（由太阳表面附近的静止和爆炸过程驱动）向地球的磁层、电离层和高层大气转移能量和动量的动力学过程之前，还有很多工作要做。人们日益认识到，这样做需要协调使用多种数据集，包括各种单独的航天器和战略位置的地面观测站。由于地球磁场最远到达太空的部分在高纬度地区与地面相交，地面磁力计阵列长期以来一直是监测磁层偏远地区过程的重要手段。该提案要求支持继续操作和分析来自四个搜索线圈磁力计的数据，这些磁力计位于北美地区的高纬度地点，两个在南极洲（南极和麦克默多），两个在北极（格陵兰岛的sondrestrom峡湾和加拿大努纳武特的伊克鲁特）。南极和伊克卢特在近尖端纬度提供了紧密的磁场共轭，而伊克卢特和sondrestrom峡湾在相似的北纬提供了数据，但当地时间间隔为1.5小时。在白天，这些位置为磁层边界和磁层与磁层的相互作用提供了一个窗口，在夜间，它们为亚暴活动的发展提供了一个越来越受欢迎的高纬度视角。提案人还参与分析来自其他高纬度地面仪器阵列的数据，包括美国和英国的多仪器AGO（自动地球物理观测站）和在南极洲开发的自主磁力计阵列，以及加拿大北极的MACCS和CANOPUS磁力计阵列。本项目中搜索线圈磁强计的10 Hz采样率为这些地区其他搜索线圈和磁通门磁强计系统（= 2 Hz）更有限的采样率提供了重要补充。综上所述，这些仪器可以研究ULF变化的整个范围，从pc1和Pi 1脉动到pc5脉动，具有高灵敏度。这些磁力计与设在南极地点的其他仪器以及低空和高空卫星的数据相结合，在各种地球空间现象的研究中已经发挥了重要作用，我们预计将继续发挥重要作用。在接下来的三年里，我们预计我们的科学工作将集中在(a)几类pc1和pc2波（0.2-1 Hz）的研究，包括在北极观测到的波，即所谓的“地幔波”；(b) pc3 -4脉冲的传播和准周期（QP）发射的产生，一类在pc3 -4频率（15-60 mHz）调制的ELF/VLF发射；(c)短周期和长周期不规则极低频波的研究，特别是在亚暴和磁暴期间。与这些数据集相关的分析和数据处理工作非常适合本科生和研究生的研究参与，并建立在教师和本科生研究的持续强大计划的基础上。

Since the beginning of the space age increasingly sophisticated efforts have been made to explore and understand Earth's space environment. Scientists now understand much about the configuration of the ionosphere and the region above it, the magnetosphere, but much remains to be done before we fully understand the dynamical processes involved in transferring energy and momentum from the rapidly changing solar wind (driven by both quiescent and explosive processes near the surface of the Sun) into Earth's magnetosphere, ionosphere, and upper atmosphere. It is increasingly understood that doing so requires the coordinated use of multiple data sets, including both a variety of individual spacecraft and strategically located ground observatories. Because those parts of Earth's field that reach farthest out into space intersect the ground at high latitudes, arrays of ground magnetometers have long been a valued means of monitoring processes in remote parts of the magnetosphere. This proposal requests support to continue to operate and analyze data from four search coil magnetometers located at high latitude sites in the North American sector, two in Antarctica (South Pole and McMurdo) and two in the Arctic (Sondrestromfjord, Greenland, and Iqaluit, Nunavut, Canada). South Pole and Iqaluit provide close magnetic conjugacy near-cusp latitudes, while Iqaluit and Sondrestromfjord provide data at similar northern latitudes but with a local time separation of 1.5 hours. During daytime hours these locations provide a window to the magnetospheric boundary and the interactions of the magnetosheath with the magnetosphere, and during nighttime hours they provide an increasingly appreciated high-latitude perspective on the development of substorm activity. The proposers are also involved in analysis of data from other high latitude arrays of ground-based instruments, including the multi-instrument U.S. and British AGO (Automated Geophysical Observatory) and developing autonomous magnetometer arrays in Antarctica, and the MACCS and CANOPUS magnetometer arrays in Arctic Canada. The 10 Hz sampling rate of the search coil magnetometers in this project provide an important complement to the more limited sampling rates of other search coil and fluxgate magnetometer systems (= 2 Hz) in these regions. Taken together, these instruments make it possible to study the entire range of ULF variations, from Pc 1 and Pi 1 pulsations down to Pc 5 pulsations, with high sensitivity. In conjunction with data from other instruments located at the Antarctic sites and with both low-altitude and high-altitude satellites, these magnetometers have played, and we expect will continue to play, a significant role in a variety of studies of geospace phenomena. During the next three years we expect our scientific efforts to focus on (a) studies of several classes of Pc 1 and 2 waves (0.2-1 Hz), including waves observed poleward of the cusp, so-called "mantle waves"; (b) the propagation of Pc 3-4 pulsations and the generation of quasiperiodic (QP) emissions, a class of ELF/VLF emissions modulated at Pc 3-4 frequencies (15-60 mHz); and (c) studies of both short-period and long-period irregular ULF waves, especially during substorms and magnetic storm periods. Analysis and data processing efforts associated with these data sets are highly suitable for undergraduate as well as graduate research participation, and build on continuing strong programs of faculty and undergraduate student research.