A coupled-map model for the magnetotail current sheet

Abstract

A magnetic field model of the magnetotail current sheet in the form of a coupled-map lattice (CML) is presented. It is a continously driven and based on the MHD diffusion equation. Solar wind vB(s) data (solar wind speed multiplied by the southward component of IMF) are used for driving the model, and it is shown to exhibit perturbations (avalanches) with power-law scalings in their distributions of duration and size. Such distributions may indicate self-organized critical (SOC) behavior. Furthermore, it is shown that the power spectra of the model outputs are of bicolor power-law form with different slopes for high and low frequencies. The model parameters determine the frequency of the break points of the spectra, and the slopes of their low and high frequency regimes.