The asymmetric geomagnetic pulsations excited by the interplanetary shock

This paper studied the asymmetric geomagnetic pulsations excited by sharp variations of solar wind dynamical pressure (Psw). The sharp decrease of Psw can excite a global pulsation in the period range 100-200 s at both low and sub-auroral latitudes due to the oscillation of magnetopause around its new equilibrium position after abrupt displacement. The frequencies of pulsations at the morning and afternoon stations are 9.8 mHz and 5.0 mHz respectively. Therefore the radius of afternoon magnetopause is about 1.16 times that of morning magnetopause, which is consistent with the observation of low latitude H components.