A b s t r a c t By analyzing the variations of global electron content (GEC) during geomagnetic storm events, the ratio "GEC/GEC QT " is found to be closely correlated with geomagnetic Kp index and time weighted Dst index, where GEC QT is the quiet time reference value. Moreover, the GEC/GEC QT will decrease with the increase of the solar flux F10.7 index. Furthermore, we construct a linear model for storm-time response of GEC. Eighty-two storm events during 1999-2011 were utilized to calculate the model coefficients, and the performance of the model was tested using data of 8 storm events in 2012 by comparing the outputs of the model with the observed GEC values. Results suggest that the model can capture the characteristics of the GEC variation in response to magnetic storms. The component describing the solar activity influence shows a counteracting effect with the geomagnetic activity component; and the influence of Kp index causes an increase of GEC, while the time weighted Dst index causes a decrease of GEC.

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