[en] The authors present an alternative explanation for the source of transient ionospheric flows. Auroral transients, and the appearance and acceleration of new arcs near the dayside oval have been commonly explained in terms of the merging rate and flux transfer events (FTE's). It is generally accepted that flow in the ionosphere is controlled by the y and z components of the magnetic field in the magnetosheath, and flows in the magnetosheath. Here the authors argue that the transients observed in ionospheric flows are the result of abrupt changes in flows in the magnetosheath, and its field components. In particular they argue that there is no compelling reason that merging rate change. Their theory seems able to explain this class of transient ionospheric events, as well as a much wider set of transient phenomena