Correlation between auroral activity and rate of development of a storm in its main phase

We investigated the relationship between the rate of storm development in its main phase (|ΔDst|/ΔT) and the average value (ΣAE/ΔT) of AE index for the main phase where |ΔDst| is the Dst-index variation, ΣAE is the total value of AE index for the main phase of magnetic storm, ΔT is the main phase duration. We considered storms initiated by corotating interaction region (CIR) and interplanetary coronal mass ejection (ICME) (magnetic cloud and ejecta). For CIR events, the value of ΣAE/ΔT is shown to correlate with the rate of storm development in its main phase in contrast to the storms initiated by the ICME. As found, there is a weak correlation between ΣAE/ΔT and the minimum value of Dst index for CIR and ICME events.