Ensemble forecasting model for geomagnetic disturbance

Ensemble forecasting has been shown to offer a systematic improvement in the skill of weather and climate prediction with different models. However, little such work has been done for space weather prediction. Referring to the ensemble forecasting technique in weather prediction, a novel geomagnetic disturbance ensemble forecasting (GDEF) model is developed in this paper. This model combines two Kp forecast models, geomagnetic disturbance forecast indicators model and geomagnetic disturbance empirical energy model, with the physics-based parameter of mean solar wind speed. Applying the GDEF model to 132 events, the prediction results show that the absolute error of GDEF model is 11.55, which is obviously smaller than 12.17 and 13.85 from the two single models, respectively. Moreover, the relative error of our model is ≤10% for 28.03% of all events, ≤30% for 75.76%, and ≤50% for 90.15%, which is better than those of the individual models. These results demonstrate that the GDEF model can utilize the advantages of each single model and improve the accuracy of prediction. Thus, developing ensemble forecasting technique is an effective way of improving space weather prediction.