Fig. 8

Solar wind conditions and geomagnetic response for 17 March storm. Plotted are magnetic field intensity (B), Bz component in GSM coordinates, solar wind Vx, dynamic pressure (P _d), solar wind electric field (E _y = Bz × Vx), the convolution S defined by Eq. (5), the observed Dst (dashed line) and the modified Dst (solid line), the time derivative of modified Dst, and Q _obs defined by Eq. (3), where values for τ = 4.0, 6.0, and 8.0 h are plotted by solid, dotted and dashed lines, respectively. Note the similarity of S curve to Q _obs for τ = 4.0, and the difference between S and E _y. The S curve shown here is for the parameter set, for \( T_{\text{d}} \), \( T_{\text{r}} \), \( T_{\text{m}} \), \( T_{\text{f}} \) = 40, 10, 90, 30 min