A theoretical F region study of ion compositional and temperature variations in response to magnetospheric storm inputs

The response of the high-latitude F region to magnetospheric storm inputs is modelled. During the 'storm', the spatial extent of the auroral oval, the intensity of the precipitating auroral electron energy flux, and the plasma convection pattern were varied with time. During the storm growth phase, the auroral oval expanded, the precipitating electron energy flux increased, and the magnetospheric convection pattern changed from a symmetric two-cell pattern with a 20 kV cross-tail potential to an asymmetric two-cell pattern with a total cross-tail potential of 90 kV. During the storm, there were significant changes in the ion temperature, ion composition, and molecular/atomic ion transition height. The storm time asymmetric convection pattern produced an ion temperature hot spot at the location of the dusk convection cell that contained significantly enhanced NO(+) densities. During the storm recovery phase, the decay of these densities closely followed the decrease in the plasma convection speed.