A STATISTICAL STUDY OF THE RELATIONS BETWEEN SOLAR FLARES AND MAGNETIC STORMS
JIANG BAI-QIN (Institute of Geophysics and Meteorology, Academia Sinica)
The author has analysed the data of solar flares and magnetic storms for ten and half years (January, 1947-June, 1957). During this period there occurred 276 storms (out of 625 in total) probably originated from flares, about 44.2 % of the total. The results of this statistical study are: (1) Magnetic storms, which had the characteristics of sudden commencement and main phase (specially those storms strongly disturbed and of non-recurrence type), were most likely originated from solar flares; (2) Solar flares according to its "class of importance"have different storm-producing effects. Those of class Ⅲ have had more frequencies to originate storms, and the storms therefrom have for the most part had sudden commencement and main phase; (3) Flares of class Ⅱ in the belt inside 45° from the central meridian in the Sun s disk had more notably effects in originating storms than those outside 45°; and especially those inside 30° have most probably caused severe storms; This fact of the distribution of stormeffective flares may suggest that the conical angle of emission of corpuscles is usually restricted to about 45°, and even to about 30° for more intense streams; (4) The flare-storm interval varies considerably and, as shown in the frequency distribution curve, it has ranges from 45 to 55 hours, and the average value is 52.2 hours.