Geospace Phenomena: Assessing Danger and Understanding Mechanisms

太阳风与地球的相互作用，就像我们熟悉的风一样，会带来破坏性的风暴。能量可以在“亚暴”中以爆炸性的方式释放，这通常以戏剧性的极光为特征。这种“太空天气”发生在近地空间的湍流等离子体中。表征它需要在地球和太空的许多点同时测量，我们的物理理解是基于对关键位置数据的仔细解释。磁层或地球周围的保护性磁壳的物理学仍然是科学上的一个重大挑战。我们必须推断出物质和能量是如何在地球附近运动的，通常只需要很少的数据。我的研究使用磁场和我们在地面上测量的其他量来填补太空天气之谜缺失的部分。我们在加拿大的仪器进行的测量与现代卫星舰队的测量相辅相成。通过提高我们对那里发生的复杂过程的理解，我们还将使从导航到电力传输等领域的实际应用成为可能。

The solar wind's interaction with Earth can, like the familiar wind, bring on damaging storms. Energy can be released in an explosive way in “substorms”, which often feature dramatic auroras. This “space weather” takes place in the turbulent plasmas of near-Earth space. Characterizing it requires simultaneous measurements at many points on Earth and in space, and our physical understanding is based on careful interpretation of data from critical locations. The physics of the magnetosphere, or protective magnetic shell around the Earth, remains a major challenge in science. We must infer how matter and energy move near Earth, often from a minimum of data. My research uses magnetic fields and other quantities we measure on the ground to supply missing pieces of the space weather puzzle. Our instruments in Canada make measurements complementary to those from modern fleets of satellites. By improving our understanding of the complex processes that take place there, we will also enable practical applications in areas ranging from navigation to power transmission. My unique world-class auroral observatory is located below the transition region between the auroral zone and the radiation belts. Some flows of plasma gas in the magnetosphere are like gentle breezes, but some particles are accelerated to energies that make them “radioactive”. Canada's ideal location allows investigating the processes that make auroras, including the mysterious “proton auroras”. We have magnetic detectors that stretch as far as Québec, with important and unique links to Antarctica through magnetic field lines. Beyond simply measuring magnetic fields from the whole magnetosphere and ionosphere, we have developed powerful techniques for pinpointing their origins. Adding in space-based measurements such as those of the AMPERE satellite constellation, we can determine electric currents, an important element in the control of space plasma. These space electric currents cause magnetic deviations on Earth that in extreme cases can damage our technological systems. We will systematically use magnetic fields, including those from corresponding Antarctic sites, to determine near-Earth currents at many levels of activity, measuring the response in both hemispheres and evaluating how this varies with solar wind conditions. We will perform detailed event studies of those storms and substorms for which there is excellent satellite placement, to determine the dynamics of the magnetosphere in active times. Our long-term goal is a space weather predictive ability based on ground magnetic fields. The practical aspect of our work will go forward locally through studies of effects on power grids. An innovative training program will be based on student stays at our observatory and supervision of students in graduate programs at other universities.