论文部分内容阅读
A so-called ISF method for predicting geomagnetic disturbances caused by solar wind storm blowing to the earth is suggested. The method is based on a combined approach to solar activity, interplanetary scintillation (IPS) and geomagnetic disturbance observations in 1966-1982, dynamics of disturbance propagation and fuzzy mathematics. Prediction test has been made for 24 large geomagnetic disturbance events that produced space disasters during the period of 1980-1998, with the three-dimensional propagation characteristics, the best close degree of each radio source and the influence of the south-north components of interplanetary magnetic fields considered. The main results are (I) for onset time of the geomagnetic disturbance, events with relative error △Tpred/Tobs≤10% between the observation Tobs and the prediction Tpred, account for 45.8% of all events, ≤30% for 78.3% and >30% for only 21.7%; (ii) as for the magnetic disturbance magnitude, events with relative error △∑Kp,pred/∑Kp,obs≤10% between the observation ∑Kp,obs and the prediction ∑Kp,pred, account for 41.6% of all events, ≤30% for 79% and ≤45% for 100%. For example, the prediction test of April-May event in 1998 indicates that △Tpred/Tobs=7.4%, △∑Kp,pred/∑Kp,obs=15.3%. Our result shows that the prediction method suggested in this paper has encouraging prospects in improving geomagnetic disturbance prediction in space weather events.