Total electron content of the ionosphere at 31°S, 1967–1974

Abstract

The total electron content (TEC) of the ionosphere at 31°S (geographic) has been calculated on the basis of Faraday rotation measurements made between September 1967 and January 1975 using geostationary satellites. The day-to-day, diurnal, seasonal and solar cycle variations of TEC are illustrated and discussed in relation to the maximum electron density of the F-layer, NMAX. A regression analysis is used to derive curves corresponding to fixed high and low levels of activity. The variations of slab thickness S = TEC/ NMAX are also illustrated and discussed. The results overlap the observation periods of other published results and general agreement is found with these other results.