Dependence of Great Geomagnetic Storm ($\Delta $SYM-H$\le -200$ nT) on Associated Solar Wind Parameters

We use $\Delta$SYM-H to capture the variation in SYM-H index during main phase of a geomagnetic storm. define great storms as those with $\le$ -200 nT. After analyzing data that were not obscured by solar winds, we determined 11 such occurred cycle 23. calculated time integrals for southward interplanetary magnetic field component I(B$_s$), wind electric I(E$_y$), and combination E$_y$ dynamic pressure I(Q) The strength correlation coefficient (CC) between each three I(B$_s$) (CC = 0.74), I(E$_y$) 0.85), 0.94) suggests Q, which encompasses both pressure, is driving factor determines intensity results also suggest impact B$_s$ on storm much more significant than speed associated How estimate an extreme based parameters discussed.