On the relationship between ion upflow events and cusp auroral transients

Abstract

In this paper we present a one-to-one relationship between poleward moving auroral forms (PMAFs) and ion upflows in the cusp. Ion upflows have the same quasi-periodic nature as cusp auroral transients, which are believed to be a signature of flux-transfer events. This new observation corroborates the idea that low energy particle precipitation is the dominant source of energy for ion upflows. Some events were lacking elevated Ti which indicates that frictional heating is not required. The ion upflow events broadened with altitude in characteristic V-shape. We suggest that each PMAF was associated with an inverted V- potential structure moving over the radar. Copyright 2004 by the American Geophysical Union.