Using the 1-D mhd model we have studied the response of the magnetopause
boundary and magnetospheric magnetic field to a pressure impulse. The work,
submitted to Annales Geophysicae, develops pioneering analytical work by Willis (1964)
and a more recent analytical theory by Freeman et al. (1995).
The magnetopause is a free boundary in the simulation that is put into motion by the transmission and reflection of the pressure impulse at the magnetopause tangential discontinuity. The compressional wave is partially trapped in the magnetosphere by a reflecting ionospheric boundary condition.
Its amplitude in the magnetosphere diminishes with each successive magnetopause encounter, progressively slowing the initial magetopause motion. The simulations make clear and new predictions for the fine structure of the magnetic "Sudden Impulse" signature and for the interpretation of spacecraft data in the magnetopause vicinity.
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