A study of the equatorial electrojet—I An experimental study

Abstract

An account is given of the photographic registration of the variation of the earth's horizontal magnetic force ( H) across the magnetic equator in Nigeria from November 1956 to January 1957. As the period was magnetically quiet and the records were good, it has been possible to make a detailed study of the quiet day variation. The latitude of the maximum range of H was found to be about 0.5° from the magnetic towards the geographic equator. The daily variation curve of H is found to change its form as the magnetic equator is crossed from south to north and a method is introduced for the study of this change. It is shown that the fluctuations in H-variation curve characteristic of equatorial stations occur at the same time and in the same form at equatorial stations that may be distant from one another. The magnitudes of the same fluctuation at two stations are in about the same ratio as the daily ranges at the stations. It is thus likely that the indentations in the H-variation curve arise from fluctuations in the ionizing agent from the sun.