Spectral analysis of turbulent effects on resistivity and the tearing instability

A spectral numerical-simulation code and ancillary diagnostics are used here to analyze the behavior of resistive magnetic tearing in the presence of short-wavelength turbulence. It is found that, in general, the anomalous resistivity defined by Biskamp and Welter (1983) due to short-wavelength turbulence tends to return quickly towards zero even when artificially supported away from zero, and that its effect on tearing-mode behavior is not consistent with its interpretation as a resistivity. The behavior reported by Biskamp and Welter and the behavior observed here are analyzed. It is argued that, while not meaningful as a true resistivity, the anomalous resistivity parameter is a useful diagnostic showing the energy balance of the system.