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A Kinetic Alfvén Wave Cascade Subject to Collisionless Damping Cannot Reach Electron Scales in the Solar Wind at 1 AU

Borovsky, J. E.; Podesta, J. J.; Gary, S. P.

Turbulence in the solar wind is believed to generate an energy cascade that is supported primarily by Alfvén waves or Alfvénic fluctuations at MHD scales and by kinetic Alfvén waves (KAWs) at kinetic scales k _bottomρ _i >~ 1. Linear Landau damping of KAWs increases with increasing wavenumber and at some point the damping b…

A Universal Law for Solar-wind Turbulence at Electron Scales

Galtier, S.; Meyrand, R.

The interplanetary magnetic fluctuation spectrum obeys a Kolmogorovian power law at scales above the proton inertial length and gyroradius which is well regarded as an inertial range. Below these scales, a power-law index around -2.5 is often measured and associated with nonlinear dispersive processes. Recent observations reveal a third region at …

Whistler Turbulence Wavevector Anisotropies: Particle-in-cell Simulations

Saito, Shinji; Gary, S. Peter; Narita, Yasuhito

Two-dimensional electromagnetic particle-in-cell simulations of whistler turbulence in a magnetized, homogeneous, collisionless plasma of electrons and protons are carried out. Enhanced magnetic fluctuation spectra are initially imposed at relatively long wavelengths, and, as in previous such simulations, the temporal evolution shows a forward cas…

Measurements of Rapid Density Fluctuations in the Solar Wind

Bale, S. D.; Kellogg, P. J.; Malaspina, D. M. +1 more

The power spectrum of density fluctuations in the solar wind is inferred by tracking small timescale changes in the electron plasma frequency during periods of strong Langmuir wave activity. STEREO electric field waveform data are used to produce time profiles of plasma density from which the density power spectrum is derived. The power spectra ob…