Magnetohydrodynamic sMHDd turbulence has been employed as a physical model for a wide range of applications in astrophysical and space plasma physics. This Colloquium reviews fundamental aspects of MHD turbulence, including spectral energy transfer, nonlocality, and anisotropy, each of which is related to the multiplicity of dynamical time scales that may be present. These basic issues are disc...

An anisotropic shell model has been proposed for two-dimensional (2D) turbulence. It is similar to the 2D version of the Gledzer-Ohkitani-Yamada model but with the angular variable in wave-number space divided into three distinct directions representing structures elongated in different directions. In the case when the drive is isotropic the usual isotropic solution is recovered as the fixed po...

In this experimental study, a column of heavy gas (SF6) surrounded by light gas (air) is accelerated by a planar Mach 1.2 shock. Richtmyer-Meshkov instability on the initially diffuse air-SF6 interface determines the repeatable large-scale vortex dynamics of the system after the shock passage. Subsequently secondary instabilities form, with the system eventually transitioning to turbulence. We ...

The nature of magnetohydrodynamic (MHD) turbulence is analyzed through both temporal and spatial magnetic fluctuation spectra. A magnetically turbulent plasma is produced in the MHD wind tunnel configuration of the Swarthmore Spheromak Experiment. The power of magnetic fluctuations is projected into directions perpendicular and parallel to a local mean field; the ratio of these quantities shows...

[1] The first fully three‐dimensional particle‐in‐cell (PIC) simulation of whistler turbulence in a magnetized, homogeneous, collisionless plasma has been carried out. An initial relatively isotropic spectrum of long‐wavelength whistlers is imposed upon the system, with an initial electron b = 0.10. As in previous two‐dimensional simulations of whistler turbulence, the three‐dimensional system ...

The effect of small scale forcing on large scale structures in β-plane twodimensional (2D) turbulence is studied using long-term direct numerical simulations (DNS). We find that nonlinear effects remain strong at all times and for all scales and establish an inverse energy cascade that extends to the largest scales available in the system. The large scale flow develops strong spectral anisotrop...