The motion of magnetic flux tube at the dayside magnetopause under the influence of solar wind flow

Abstract

We propose that flux transfer events (FTEs) at the dayside magnetopause are formed by fluid vortices. in the flow field. According to the view of vortex-induced reconnection a FTE tube is a magnetic fluid vortex tube (MF vortex tube). The motion of a FTE tube can be represented by that of a MF vortex in the formation region located in the dayside magnetopause region. This study deals with the internal and external influences governing the motion of MF vortex tubes.The equations of motion of a vortex tube are established and solved. It is found that a FIE tube moves from low latitude to high latitude with a certain speed. However, the mofional path is not a straight line but oscillates about the northward direction for the northern hemisphere. The motional velocity, amplitude and period of the oscillation depend on the flow field and magnetic field in the magnetosheath and magnetosphere as well as the size of the FIE tube.