Energy dissipation by whistler turbulence: Three-dimensional particle-in-cell simulations

Three-dimensional particle-in-cell simulations of whistler turbulence are carried out on a collisionless, homogeneous, magnetized plasma model. The simulations use an initial ensemble of relatively long wavelength whistler modes and follow the temporal evolution of the fluctuations as they cascade into a broadband, anisotropic, turbulent spectrum at shorter wavelengths. For relatively small levels of the initial fluctuation energy epsilon(e), linear collisionless damping provides most of the dissipation of the turbulence. But as epsilon(e) and the total dissipation increase, linear damping becomes less important and, especially at beta(e) << 1, nonlinear processes become stronger. The PDFs and kurtoses of the magnetic field increments in the simulations suggest that intermittency in whistler turbulence generally increases with increasing epsilon(e) and beta(e). Correlation coefficient calculations imply that the current structure dissipation also increases with increasing epsilon(e) and beta(e), and that the nonlinear dissipation processes in these simulations are primarily associated with regions of localized current structures. (C) 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License.