Generation of plasma turbulence and radio emission at the front of interplanetary MHD shocks.

Abstract

Based on spectral observations of turbulence and radio emission in the interplanetary medium from the Ulysses spacecraft, we describe processes responsible for the formation of energetic particle fluxes, the generation of Langmuir and ion acoustic turbulence, and the radio emission at the front of a quasi-perpendicular MHD shock wave. It is shown that an important role in the production of energetic particle fluxes and the generation of emission is played by a collisionless density jump in the shock structure that corresponds to a nonlinear ion acoustic wave.