A study of commercial time lost on transatlantic radio circuits due to disturbed ionospheric conditions

An analysis has been made of the time lost on certain radio circuits incoming to the United Kingdom from Montreal and New York during the period 1942¿1952. The results have been examined in relation to the variations in solar and magnetic activity with a view to estimating the degree of interruption likely to be experienced on transatlantic circuits during the next few years. It is concluded that the maximum values of lost time occur during the winter months as the minimum of the sunspot cycle is approached, and that these high values are associated with periods of high magnetic activity arising from the occurrence of M-region storms. It is considered that the adverse propagation conditions encountered since the winter of 1950¿51 will be slightly less severe during the winter of 1954¿55 and that by the winter of 1955¿56 there should be a marked reduction in the amount of commercial time lost on transatlantic circuits.