Poynting flux of oblique whistler waves observed in front of a high mach number quasi-perpendicular collisionless shock

Whistler waves are observed in the foot region of a high Mach number quasi-perpendicular shock. The whistler waves are oblique with respect to the ambient magnetic field. The Poynting flux of the whistler waves is nonzero and upstream in the shock normal indicence frame starting from the foot of the ramp, suggesting that the waves are an integral part of the shock structure with the dispersive shock as the source of the waves. This demonstrates that dispersive effects are important also for high mach number shocks.