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 (...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.展开更多
基金This work was jointly supported by the National Key Basic Research Science Foundation (Grant NO. G2000078405) and the National Natural Science Foundation of China (Grant Nos. 49925412 and 49990450).
文摘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.
