The measurement of ionospheric absorption using observations of 18·3 Mc/s cosmic radio noise

Abstract

A new technique permits measurement of the total attenuation suffered by 18·3 Mc/s cosmic radio noise passing completely through the ionosphere. It is shown that the total absorption may be divided into two components, one due to absorption mainly in the D region and the other in the F₂ region. The observations of D region absorption confirm the diurnal and seasonal variations observed by other workers. F₂ absorption depends on the critical frequency but not on the height of the region and there is evidence of increased absorption at night which may be caused by irregularities in the upper F region. The observational results are compared with those obtained by other workers and suggestions are made for the use of the method, particularly in the exploration of the upper F₂ region.