The observation of isolated long-lived current filaments in two-dimensional microtearing turbulence

Abstract

Long-lived isolated current filaments are found to evolve from an initially random current distribution in a numerical simulation of 2-D microtearing, i.e., coupled electron density and flux evolution similar to two-dimensional magnetohydrodynamics (MHD). These filaments arise under the constraint of mean square flux conservation with negligible resistive dissipation and finite cross-field particle diffusivity. The kurtosis of current is found to be large (≫3) indicating strongly non-Gaussian or intermittent behavior. Isolated filaments appear to be force-free. Like sign filaments are observed to attract and merge. © 1991 American Institute of Physics.