A study of 2-Mc/s ionospheric absorption measurements at high latitudes

Abstract

Ionospheric absorption (L) at high latitudes is studied using the published data on 2.0 Mc/s at five Canadian stations during 1957 and 1958. The seasonal and diurnal variations are considered, and it is found that a pronounced winter anomaly in noon absorption occurs at Churchill but not at Resolute Bay. The diurnal variations indicate that the dependence of absorption on solar zenith angle decreases with increase of latitude. The distribution of midnight absorption with latitude shows that, although the maximum occurs in the auroral zone, high absorption is also encountered over the polar cap. A study of the duration of long-lasting blackouts shows that in summer the duration is longer as the latitude increases.