Theoretical Model of Traveling Convection Vortices

Abstract

A theoretical model has been constructed to explain the formation of traveling convection vortices. This model proposes that traveling convection vortices correspond to kink instabilities generated in magnetospheric regions where the current is strong enough to create an azimuthal field B_θ of the same size as the field aligned component B_z in the equatorial plane. It is assumed that in these regions (around 4R_e), this current produces an azimuthal magnetic field which creates a kind of instability, known as the kink instability. The results of model calculations based on typical values observed on spacecraft have been compared with the patterns of traveling convection vortices derived from ground based magnetometers. The multiple current filaments which are often observed in these patterns are proposed to be explained by the occurrence of kink instabilities in the magnetosphere.