Renormalization-group study of a sandpile (FSOC)analog for magnetospheric activity

Abstract

It has been suggested that the dynamics of the magnetotail may exhibit forced and/or self-organized critical behaviour. Recent analysis of experimental data seem to be in concert with this idea. These suggestions and indications have re-motivated interest in sandpile (avalanche) models. Some examples of specific interest for geomagnetic activity have the property that internal avalanches exhibit inverse power law statistics whereas systemwide avalanches have a well-defined mean. Here we apply the concept of a renormalization group to such a model. We demonstrate that invariant analysis based on the renormalization-group theory can explain the power law distribution of energy release by internal avalanches in then large-scale regime of these systems