Plasma wave signatures of collisionless shocks and the role of plasma wave turbulence in shock formation

High‐frequency electrostatic waves near Earth's bow shock

“…Once the wave modes are identified, the effects of the waves on the plasma can be evaluated, and the issues of beam persistence far downstream from the shock can be addressed. Although the role of electrostatic waves in the plasma heating at shocks has recently been called into question [Scudder et al, 1986;Mellott, 1986], the wave spectra do vary considerably at collisionless shocks and therefore present valuable clues toward understanding the large-and small-scale processes occurring in the collisionless plasma.…”

Low-frequency waves upstream and downstream of the terrestrial bow shock

“…Turbulence in space plasma has been most extensively studied in the solar wind, but the power spectra of the magnetic or velocity field fluctuations could be investigated only in the frequency domain, since the spacecraft have made one-or at best two-point measurements (Scarf et al 1981, Mellott 1986, Moustaizis et al 1986, Clasßen et al 1999, Bavassano Cattaneo et al 2000, Borovsky et al 2003. Earlier observations have already shown that power spectra of the magnetic or velocity fields often contained an inertial range with a slope of approximately -5/3 (Coleman 1966(Coleman , 1967(Coleman , 1968, and also different slopes depending on frequency scale: -1/3, -1, and -5/3 (Goldstein and Roberts 1999).…”

Fundamentals of Non-relativistic Collisionless Shock Physics: IV. Quasi-Parallel Supercritical Shocks

“…Long-period ∼ 30 s waves are the rule in the foreshock. They occur together with the diffuse foreshock-ion component [cf., e.g., 80,113] which is located deeper inside the foreshock. Because of this reason, any waves that are excited by the diffuse ion component are restricted to the interior of the foreshock.…”