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

自空间时代开始以来，为探索和了解地球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区域磁层的结构有了很大的了解，但是在我们完全理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）向地球磁层、电离层和高层大气转移能量和动量的动态过程之前，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个数据集，其中既包括各种单独的航天器，也包括位于战略位置的地面观测站。由于地球磁场中最远到达太空的部分在高纬度与地面相交，因此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。该提案要求提供支助，以继续运行和分析位于北美区高纬度地点的四个搜索线圈磁力计的数据，其中两个在南极洲（南极和麦克默多），两个在北极（格陵兰的Sondrestromfjord和加拿大努纳武特的伊卡卢伊特）。南极和伊卡卢伊特提供了接近磁共轭的近尖点纬度，而伊卡卢伊特和南斯特龙峡湾提供了类似北方纬度的数据，但当地时间间隔为1.5小时。在白天，这些位置提供了一个窗口，磁层边界和磁鞘与磁层的相互作用，在夜间，它们提供了一个越来越受赞赏的高纬度亚暴活动的发展前景。提议者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自动地球物理观测站（AGO）和在南极洲开发自主磁强计阵列，以及加拿大北极地区的MACCS和CANOPUS磁强计阵列。本项目中探测线圈磁力仪的10 Hz采样率为这些区域中其他探测线圈和磁通门磁力仪系统（= 2 Hz）更有限的采样率提供了重要补充。总之，这些仪器使得研究整个范围的超低频变化成为可能，从Pc 1和Pi 1脉动到Pc 5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一起，在对地球空间现象的各种研究中发挥了重要作用，我们预计将继续发挥重要作用。在今后三年中，我们希望我们的科学努力集中在（a）几类Pc 1和2波的研究（0.2-1赫兹），包括在尖点向极方向观察到的波，即所谓的“地幔波”;（B）Pc 3-4脉动的传播和准周期（QP）发射的产生，一类调制在Pc 3-4频率（15-60兆赫）的极低频/甚低频发射;（c）研究短周期和长周期不规则超低频波，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的计划。

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.