The paraday effect and the variation of toatal electron content near the Equator

Abstract

The Appleton-Hartree expressions for the polarisation (of a plane radio wave in a non-isotropic medium) and the refractive index (of a oharaoteristic wave) are derived from standard Magnetoionic Theory. The Faraday rotation of the plane of polarisation of a linearly polarised radio signal is considered and the formula for oalculating the Total Electron Content of the ionosphere for the case of quasi-longitudinal oonditions is derived. Although the quasi-transverse region forms a small fraotion of the latitude coverage for eaoh Faraday record.analysed, it is disoussed in a fair amount of detail. The Total Electron Content values derived from observations are looked at in various ways, including,

diurnal variation,

magnetic activit,y effects, seasonal variation.

The results are examined for evidence of the 'Equatorial

Anomaly' in the Total Electron Content of the ionosphere~