Generation of traveling convection vortices and field-aligned currents in the magnetosphere by response to an interplanetary tangential discontinuity

Three-dimensional global magnetohydrodynamic simulations are conducted to s tudy the response of the magnetosheath and the magnetosphere to an interpla netary tangential discontinuity (TD), across which the plasma density incre ases. A fast mode wave and a transmitted TD are generated in the magnetoshe ath by the interaction between the interplanetary TD and the bow shock. The se waves further propagate and disturb the dayside magnetosphere. The fast mode compressional wave propagates downstream out of the dayside region in about 1 minute. The pressure enhancement associated with the transmitted TD later compresses the magnetopause significantly for several minutes. The g eneration of traveling convection vortices, shear Alfven waves, and the ass ociated field-aligned currents (FACs) in the dayside magnetosphere by these pressure pulses is identified in the simulation.