LARGE AMPLITUDE ALFVEN WAVES AT THE MAGNETOPAUSE

K. STASIEWICZ(1); Y. KHOTYAINTSEV(1); G. GUSTAFSSON(1); P-A

LINDQVIST(2); F. MOZER(3); A. ERIKSSON(1); T. CAROZZI(1)

(1) Swedish Inst. of Space Physics, Uppsala; (2) Royal Inst. of Technology,

Stockholm; (3) University of Berkeley, CA

Previous satellite missions have shown that large amplitude nonlinear Alfven waves

(structures) develop at the magnetopause in regions of oppositely oriented

magnetospheric and IMF fields. Computer simulation results indicate that these

structures may be generated by tearing mode instability, which creates density

gradients that drive small scale dispersive Alfven waves (DAW). With four Cluster

spacecraft we shall investigate the convection patterns, spatial structure, and

propagation characteristics of these waves, which appear to be important for mixing

and energization of plasma at the magnetopause boundary.