A New Test of the Magneto- Ionic Theory

Abstract

ACCORDING to the magneto-ionic theory of Appleton¹, we should expect a wireless wave incident on the ionosphere to be returned to the earth as two differently polarised components (the ordinary and the extraordinary) with a slight difference in the time of travel. For wave-lengths shorter than 214 metres (the critical wave-length of the theory, given by the expression ), the theory has been experimentally confirmed^2,3 and the following points are well established: (a) The two magneto-ionic components are circularly polarised. (b) The left-handed (ordinary) component penetrates the F region and the E region more easily than the right-handed (extraordinary). (c) The intensity of the extraordinary wave decreases markedly as the magneto-ionic critical wave-length is approached. The theory predicts different results for waves of length greater than 214 metres, but so far as we know, experiments have not been made to test it for these wave-lengths.