Grant: Discovery Development Grant

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. We must infer how matter and energy move near Earth, often from a minimum of data. The aim of my research is to use 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. The physics of the magnetosphere, or protective magnetic shell around the Earth, remains a major challenge in science. 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. Our 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 particles can be accelerated to energies that make them ""radioactive"". Our ideal location allows investigating the processes that make auroras, including the mysterious ""proton auroras"". We have magnetic detectors that stretch as far as eastern Canada, with important and unique links to Antarctica through magnetic field lines. Magnetic fields arise from the whole magnetosphere and ionosphere. Beyond simply measuring them, we have developed powerful techniques for determining where they originated. By adding in space-based measurements such as those of the AMPERE satellite constellation, we can determine electric currents in near-Earth space. This is an important element in the dynamic control of space plasma. Besides having a close association with auroras, space electric currents can 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 storms and substorms for which there is excellent satellite placement, to determine the dynamics of the magnetosphere in active times. One 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 pipelines, and in eastern Canada on power grids. An innovative training program will be based on student stays at our observatory.