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Periodic magnetic storms are those related to reccurent coronal hole events within a period of one solar rotation. There are still few studies on successive periodic magnetic storm. In this paper, we discuss the nature of the amplitude of the periodic magnetic storms within the solar cycle 20,21,22, and 23. The periodic nature of solar wind ( 27 days) occured on descending phase of solar cycle 22 also caused a reccurent geomagnetic disturbance. The disturbance developed into a geomagnetic storm in the first (27 days) and the ninth rotation. The geomegnetic disturbances with period 27 and 13.5 days are both significant at the low latitude while the period of 30 days are more dominant at the high latitude. That mean, from two flows of high velicity plasmas, only one that higher contribution on the occurence of geomagnetic disturbance accompanied by high intensity southern Bz field. |
