We extend to the magnetohydrodynamic (MHD) case a recent model of intermittency due to She and Lévêque [Phys. Rev. Lett. 72, 336 (1994)]. The model that we develop in the framework of the Iroshnikov-Kraichnan theory of MHD turbulence depends on two parameters that are linked to anomalous scaling laws of dissipative structures when their characteristic scale l→0. A brief comparison with published data stemming from spacecraft observations within the solar wind shows that it is a workable model and that within the framework of the model, dissipative structures in MHD turbulence are sheetlike, as observed in recent numerical simulations in three dimensions at moderate Reynolds numbers.

• Received 29 November 1994

DOI:https://doi.org/10.1103/PhysRevE.52.636