Swarm observation of small-scale electric and magnetic field variability in the high-latitude ionosphere

Earth’s Ionosphere at high latitudes is strongly coupled to both the magnetosphere and neutral atmosphere and involves physical processes operating at wide range spatial and temporal scales. Characteristics of small-scale (1-10s km) structures of high-latitude electrodynamics are not well-known, however they play an important role in the total energy balance of the atmosphere-ionosphere system and could be significant for accurate numerical modeling. The European Space Agency’s Swarm mission, consisting of three satellites in nearly polar, circular orbits at around 500 km altitude, has been simultaneously measuring ion electrodynamic E×B drifts and magnetic fields using Thermal Ion Imagers (TII) and Vector Field Magnetometers (VFM) for over eight years. These measurements are unique because of their high resolution (16 Hz and 50 Hz, respectively) and can be used to estimate electric fields and field-aligned currents (FACs). In this work we utilize all available Swarm TII and VFM measurements to obtain statistical characteristics of small-scale ion drift and magnetic field variability and investigate their interrelationship. The dependence on the time of day, latitude, season, and interplanetary magnetic field conditions is studied.