Magnetohydrodynamic dissipation range spectra for isotropic viscosity and resistivity

Dissipation range spectra for incompressible magnetohydrodynamic turbulence are derived for isotropic viscosity and resistivity . The spectra are obtained from heuristic closures of spectral transfer correlations for cases with Pm= / 1, where Pm is the magnetic Prandtl number. Familiar inertial range power laws are modified by exponential factors that dominate spectral falloff in the dissipation range. Spectral forms are sensitive to alignment between flow and magnetic field. There are as many as four Kolmogorov wavenumbers that parametrize the transition between inertial and dissipative behavior and enter corresponding spectral forms. They depend on the values of the viscosity and resistivity and on the nature of alignment in inertial and dissipation ranges. © 2009 American Institute of Physics. DOI: 10.1063/1.3200901