Eclipse effects in the equatorial F-region

Abstract

Ionograms taken at Maiduguri, Nigeria, during the total solar eclipse of 2nd October, 1959, have been analysed to determine the photochemical rates in the F-region. It is found that the variations of electron density at fixed altitudes are consistent with a ‘linear’ loss coefficient β which varies with altitude as β(h) = 2.45 . 10 −4 exp [ −(h−300) 84 ] sec −1 and an electron production rate q given by q(h) = 330 exp [ −(h−300) 109 ] cm −3 sec −1 . These values of q and β are shown to be consistent with measurements of other workers when allowance is made for temperature variations during the solar cycle. The transition level between a quadratic and linear loss rate is found to occur at about 300 km.