Evaluation of solar wind-magnetosphere coupling functions during geomagnetic storms with the WINDMI model

Abstract

We evaluate the performance of three solar wind-magnetosphere coupling functions in training the physics-based WINDMI model on the 3-7 October 2000 geomagnetic storm and predicting the geomagnetic Dst and AL indices during the 15-24 April 2002 geomagnetic storm. The rectified solar wind electric field, a coupling function by Siscoe, and a recent formula proposed by Newell are evaluated. The Newell coupling function performed best in both the training and prediction phases for Dst prediction. The Siscoe formula performed best during the training phase in reproducing the AL faithfully and capturing storm time events. The rectified driver was discovered to be the best in overall performance during both training as well as prediction phases, even though the other two coupling functions outperform it in the training phase. The results indicate that multiple drivers need to be concurrently employed in space weather models to yield different possible levels of geomagnetic activity. © 2009.