What can we infer about the underlying physics from burst distributions observed in an RMHD simulation?

We determine that the sizes of bursts in mean-square current density in a r educed magnetohydrodynamic (RMHD) simulation follow a power-law probability density function (PDF). The PDFs for burst durations and waiting time betw een bursts are clearly not exponential and could also be power-law. This su ffices to distinguish their behaviour from the original Bak et al. sandpile model which had exponential waiting time PDFs. However, it is not sufficie nt to distinguish between turbulence, some other SOC-like models, and other red noise sources. (C) 2001 Elsevier Science Ltd. All rights reserved.