A prediction method of geomagnetic disturbances based on IPS observations—dynamics—fuzzy mathematics

Abstract

A prediction method for geomagnetic disturbances, based on the interplanetary scintillation (IPS) observations, dynamics of interplanetary disturbance propagation and fuzzy mathematics, is suggested. The membership functions are established by using observational data on the solar storm, interplanetary and geomagnetic disturbance data in 1966–1982. Prediction tests are performed on 37 geomagnetic disturbance events caused by the solar storm-associated interplanetary disturbances, which are identified by the IPS observations during the descending solar activity phase 1984–1985. The relative error of the magnetic disturbance onset time ( δT T=7.4% ) is less than 10% for 50% of all the events and less than 20% for 70% of all the events. The relative error of the predicted magnetic disturbance magnitude ( δΔK p ΔK p ) is less than 30% for 80% of all events and greater than 60% for only 15% of all the events. In addition, the prediction test of April-May 1998 event gives the relative errors δT T=7.4% and δΔK p ΔK p = 15.3% . hese results show that the method suggested in this paper has proential prospects for improving the accuracy of the geomagnetic disturbance prediction made from IPS observations.