Integrated electron production and loss rates in the ionosphere

The deduction of the rate of change of electron content with local time from lunar radar Faraday rotation observations is discussed, and the equation of continuity for the electron content is given. Using a simple model electron density profile and assuming height dependent attachment-like loss at all levels, the equation of continuity reduces to a simple form. The rate of decrease of electron content after sunset obtained from observations at Jodrell Bank shows good order of magnitude agreement with the predictions from the simplified continuity equation ; some fairly small, apparently systematic, deviations from the predicted loss rates are discussed. The integrated rate of production of electrons has been measured just after dawn, and shows well marked variations with season and solar activity. There is some evidence that both the loss coefficient and the total production rate reduced to normal incidence have considerable diurnal variations. An upper limit of 2 × 10¹² e/m²/s can be set to the time averaged rate of production of electrons in situ during the night. The observations are not inconsistent with the existence of a downward flux of electrons from the exosphere.