THE INFLUENCE OF O+-O COLLISION FREQUENCY ON IONOSPHERIC F-REGION BEHAVIOR

Several formulae for the O+-O momentum transfer collision frequency are currently in use in aeronomical calculations. Recent experimental determinations of the collision frequency, from radar and optical observations of the ionosphere and thermosphere, are in disagreement. A mathematical model of the plasmasphere is used to investigate the effects on F-region behaviour of variations in the collision frequency. It is found that variations of the order of 30% from the Stubbe theoretical formula for the collision frequency are unlikely to have significant consequences. But the greater changes to the formula that have been suggested recently cause large departures in the density and height of the F2-peak ionisation. © 1990.