THE EFFECT OF DISTURBED-TIME ELECTRIC-FIELDS ON THE INNER PLASMASPHERE

Results from a mathematical model provide a description of the mid-lat itude, low L-shell ionosphere and plasmasphere. Variations in the comp osition and dynamics of the plasmasphere and changes in the nature of the coupling between the plasmasphere and the ionosphere are studied f or moderately disturbed conditions. Modelled results are compared to g roup delay and Doppler shift measurements of whistler mode signals at Faraday, Antarctica (L almost-equal-to 2.5), to investigate the effect s of disturbed time electric fields on the inner plasmasphere and iono sphere. The disturbed time electric field causes a rapid outward drift ing of the plasma leading to a decrease in modelled plasmaspheric elec tron density at a fixed L-value, which agrees with experimental observ ations. During the periods of outward drift, the modelled coupling flu x is upwards to the plasmasphere which can lead to a significant deple tion of N(m)F2 values.