Kinetic Alfven Waves (KAW) are believed to play an important role in the particle transport, heating, and acceleration at the magnetopause and in the substorm processes of the magnetosphere. In this talk, our global and local 3-D hybrid simulations will be presented for the generation of KAWs in the dayside and nightside magnetosphere under various interplanetary magnetic field (IMF) conditions. (1) In the cases in which the direction of IMF is such that the bow shock is a quasi-parallel shock, the interaction of kinetically excited foreshock waves/pressure pulses with the dayside magnetosphere leads to strong surface perturbations at the magnetopause. The compressional waves are found to mode convert to shear Alfven waves and KAWs through the Alfven resonance process at the magnetopause, which in turn produces field line resonance and field-aligned currents in the magnetosphere. (2) Under a southward IMF, Alfven waves as well as field-aligned ion beams are generated by magnetic reconnection in the tail plasma sheet. In the near-Earth region, large-amplitude short-wavelength KAWs are present, which propagate along field lines into the ionosphere. The simulation shows that these KAWs are generated through a phase mixing process in the plasma boundary.
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