The sporadic E layer at Kodaikanal

Abstract

An examination of the ionospheric records at Kodaikanal, which is located almost on the geomagnetic equator, reveals that the sporadic E layer here has some regular features not observed at other latitudes. It occurs in nearly 93 per cent of the half-hourly records during the daytime. Two main types of Es are observed; namely, (1) the patchy type with a well-marked diurnal variation, and (2) the blanketing type which occurs mostly during afternoons. It is found that neither meteoric activity nor thunderstorm activity has any appreciable influence on the formation of either of the two types of Es. No correlation is observed between Es and the geomagnetic field.