Spatial Structure and Field-Line Diffusion in Transverse Magnetic Turbulence

Abstract

We examine magnetic surfaces and randomization of field lines with fluctuations transverse to a uniform magnetic field. Analogy with passive scalar transport in inviscid 2D flow provides realizations of magnetic surfaces and motivates a nonperturbative statistical approach. The stochastic wandering of magnetic field lines leads to diffusive perpendicular transport. For two-component fluctuations, appropriate for solar wind turbulence, the diffusion coefficient is a nonadditive combination of slab and 2D coefficients, approaching the latter in the small amplitude limit.