Ionospheric Drifts at Brisbane

Abstract

SwmmaryExamination of fading of signals recorded at closely spaced receivers has been used' to measure the velocity of horizontal drifts of ionization in the ionosphere. Systematic observations have been made for a period of 2 years, on a frequency of 2·28 Mc/s.The results show good agreement with the horizontal velocities of ionized irregularities in the E and F 2 regions of the ionosphere as determined by other methods at similar latitudes. The speeds are less than those observed at higher latitudes.The results for the E region have been analysed for 24, 12, and 8 hr solar harmonics. The 12 and 8 hr harmonics show large seasonal phase changes in the northward component. The phase for the 12 hr northward component is in fair agreement with the results at higher latitudes in summer only, whereas the phase for the eastward component is generally consistent with the results at higher latitudes for all seasons.The F region ~2 hr harmonic has a larger seasonal phase change in the eastward component than in the northward component.