It will be demonstrated that ion kinetic effects determine not only the small scale structure, but are also of great importance for the large-scale structures during magnetotail reconnection. Auroral Radio Emissions Observed at Ground Level. These radiations do not represent a large fraction of the auroral energy budget, but they provide a nearby laboratory for studying emissions processes which occur ubiquitously in space plasmas. Also, these emissions may provide a valuable method for remote sensing auroral processes. Auroral roar and MF-burst are least understood.
Recent evidence suggests that it is concentrated at the poleward edge of the auroral zone.
Many details of the theory, especially the mode conversion mechanism, need yet to be worked out. Magnetospheric Currents determined from Ionospheric Modeling. High conductivity along lines of force of the Earth's magnetic field leads to strong electromagnetic coupling throughout the ionosphere and magnetosphere. Within the ionosphere, currents perpendicular to the magnetic field flow mainly between 100 km and 200 km altitude at day, with much weaker currents between 200 km and 400 km both day and night. The dynamics of the neutral thermosphere is strongly influenced by the Ampere force of these currents.