The probability of occurrence of F1 layer or L condition estimated by tables Original Research Article

A method for the estimation of the probability of occurrence of F1 layer and L condition based on tables is proposed. A comparison is performed between the probability of occurrence of the layer estimated by this method and the observed occurrence. The database considered for the comparison is constituted of 3 years (1964, 1968, 1957 with different levels of solar activity), which are outside the database used to obtain the tables.