Magnetospheric storm and substorms (II):: The mechanism of the effect of the solar-wind parameters on Dst

In order to study the modulating mechanism of the D-st index versus solar wind parameters, including the intherplanetary magnetic field (IMF), B-t. the solas wind speed, V-s, and the electromotive fore (EMF), U, we simulate the input-output characteristics of B-c-D-st,Vs-D-st,U-D-st with the input-output network model of the system of solar wind-magnetosphere-ionosphere. The model predicts that B-c is the prerequisite for substorms and storm, and V-s is the additional condition for them. B-z and V-s are integrated to EMF, U (t). The results are well-accordant with the observed results.