Magnetic activity and ionospheric absorption

Abstract

An analysis of ionospheric absorption enhancements on frequencies near 2 MHz following periods of magnetic activity, shows a clear latitude variation in which there is a progressive reduction with latitude in the duration of this magnetic activity after-effect and also a progressive delay in the time of commencement of the enhanced absorption. As is the case with the winter anomaly in absorption, the occurrence of absorption associated with periods of magnetic activity is not noticeable at latitudes less than 37°