Geospace Specification and Prediction using Global Low Earth Orbit Observations of the Coupling Electric Currents

The Active Magnetosphere and Planetary Electrodynamics Response Experiment (AMPERE) provides global-scale and continuous observations of the Birkeland currents linking the ionosphere to the high-altitude magnetosphere. These currents are central to high-latitude convection and energy dissipation in the ionosphere and allow specification of conditions leading to enhanced high-latitude electric fields and penetration of convection electric fields to middle and low latitudes during geomagnetically disturbed conditions. AMPERE provides 24/7, global coverage and AMPERE NEXT as implemented on Iridium NEXT offers the promise of providing this global data stream in real time with only a few minute latency relative to on-orbit data acquisition. We present analyses of the sudden development of Birkeland currents and their relationship to more familiar ground magnetic field signatures showing that the field-aligned currents on the dayside precede both the more intense onset of currents on the nightside and the corresponding ground magnetic signatures of the ionospheric electrojets. Significantly, the dayside high-latitude Birkeland currents are a precursor to the intense onset of electrodynamics on the nightside associated with space weather effects and are not detectable in ground magnetic field data. We discuss the implementation and initial data returned from AMPERE NEXT and how the real-time data stream could be harnessed to provide both specification and short-term warnings of nightside onsets.