An Investigation of the Total Electron Content in the Equatorial Anomaly of East Africa


  • A. N. Hunter,

  • F. Hibberd,

  • W. Mulokwa


Measurements of total electron content by Faraday fading have been made at three frequencies on BE-B at Nairobi from October 10, 1954, to the present day; two passes a day are recorded. Similar measurements on one frequency only have been made at Dar es Salaam and Addis Ababa. A computer program has been written which is specially suitable for low-latitude stations and computes the M values and total electron content as a function of latitude. Errors arise from reduction of the records to locate the transverse point and from approximations in the theory. However, more serious errors are due to insufficient knowledge of the effective height and inclination of the ionosphere. Comparisons of the electron content computed at Nairobi with computations made by Koster and Golton show differences in detail but agreement in general form. Many more records remain to be reduced, to which may be added results for the BE-C, but the results so far are very variable. On many occasions when an equatorial anomaly in total content is expected to show in total content, it does not appear. The expected pattern for the development of the equatorial anomaly is most apparent during the equinoxes.