Concerning the motion of flux transfer events generated by component reconnection across the dayside magnetopause

Abstract

We generate flux transfer events (FTEs) along subsolar component reconnection curves whose tilt depends upon the interplanetary magnetic field (IMF) orientation, track their motion in response to pressure gradient and magnetic curvature forces, and estimate the perturbations they produce in the ambient magnetosheath and magnetosphere. During periods of southward IMF orientation, FTEs move poleward rapidly without ever reaching the flanks of the magnetosphere, while during periods of northward and duskward IMF they slip slowly over the flanks. Speeds increase when a depletion layer is present. For southward IMF orientations, the greatest magnetic field perturbations occur near the equator and diminish with distance from the posited reconnection line. For northward and duskward IMF orientations, dayside perturbation amplitudes are lower but increase with downstream distance at off‐equatorial locations. Consequently events occurring for southward IMF orientations should dominate statistical surveys of dayside events but not those of flank events. The events move through the ambient media, invariably generating outward/inward flow perturbations in the magnetosheath but inward/outward perturbations in the magnetosphere. Multipoint spacecraft timing studies can be used to determine event axes and the component of event motion perpendicular to these axes. Because FTEs retain their initial orientations, timing studies afford an opportunity to determine the orientation of the dayside reconnection curve from remote locations.