  The 'Acceleration, Reconnection, Turbulence and Electrodynamics of the Moon's
Interaction with the Sun' (ARTEMIS) mission provides a unique opportunity to
study the structure of interplanetary shocks and the associated generation of
plasma waves with frequencies between ~50-8000 Hz due to its long duration
electric and magnetic field burst waveform captures. We compare wave properties
and occurrence rates at 11 quasi-perpendicular interplanetary shocks with burst
data within 10 minutes (~3200 proton gyroradii upstream, ~1900 downstream) of
the shock ramp. A perturbed shock is defined as possessing a large amplitude
whistler precursor in the quasi-static magnetic field with an amplitude greater
than 1/3 the difference between the upstream and downstream average magnetic
field magnitudes; laminar shocks lack these large precursors and have a smooth,
step function-like transition. In addition to wave modes previously observed,
including ion acoustic, whistler, and electrostatic solitary waves, waves in
the ion acoustic frequency range that show rapid temporal frequency change are
common. The ramp region of the two laminar shocks with burst data in the ramp
contained a wide range of large amplitude wave modes whereas the one perturbed
shock with ramp burst data contained no such waves. Energy dissipation through
wave-particle interactions is more prominent in these laminar shocks than the
perturbed shock. The wave occurrence rates for laminar shocks are higher in the
transition region, especially the ramp, than downstream. Perturbed shocks have
approximately 2-3 times the wave occurrence rate downstream than laminar
shocks.

Space Physics