The dependence of ionospheric absorption of MF radio waves at mid-latitudes on planetary magnetic activity

Abstract

A statistical analysis of MF radiowave absorption data at middle European latitudes shows that there is a positive short-term correlation (i.e. for periods of up to 30 days) with solar activity and planetary magnetic activity. The maxima and minima in mid-latitude absorption, however, occur several days after the corresponding K p variations. Since the effects are more pronounced in autumn and winter than in spring and summer, this may explain some of the published reports of anomalous winter absorption in Europe.