Novel approach to geomagnetically induced current forecasts based on remote solar observations

Abstract

In this paper, a novel approach that uses remote solar observations to forecast geomagnetically induced currents (GIC) is introduced. The approach utilizes first-principles-based propagation of the observed coronal mass ejections in the heliosphere and uses the modeled transient properties at the Earth to make site-specific statistical estimates of GIC. The approach provides unprecedented forecast lead time of 1--2 days. The approach is validated for two nodes of the North American power transmission system by means of 14 coronal mass ejection events for which GIC observations are available. It is shown that the mean of the absolute value of the error in the GIC event start time prediction is about 5 h while the length of the events is underestimated on average by 17 h. The success rate, i.e., hits versus the total number of events, of the predictions are 12/14 and 7/14 for the two GIC stations, respectively. The implications of the new approach and the accuracy of the approach are discussed and possible avenues for future improvements are outlined. Copyright 2009 by the American Geophysical Union.