Abstract :
The paper reviews the methods adopted to forecast the ionospheric disturbances that occasionally interrupt short-wave communication circuits. The normal characteristics of the ionosphere and their regular variations are briefly described. The causes and effects of the various types of ionospheric disturbances are examined and methods of predicting these disturbances discussed. It is concluded that the successful prediction of ionospheric disturbances depends on the immediate availability of the latest solar, geomagnetic and ionospheric data, and that accurate forecasts cannot be made by considering only solar or geomagnetic phenomena.