Local intermittency measure analysis of AE index: The directly driven and unloading component

Abstract

The Auroral Electrojet (AE) index, introduced to track the global high-latitude geomagnetic activity, is representative of two different processes (Kamide and Kokubun, 1996): the solar-wind directly driven convection enhancement, and the impulsive unloading process. Here, we present a new technique, based on the Local Intermittency Measure analysis, to separate these two contributions in the AE index. In detail, we applied this approach to extract the coherent intermittent structures that are linked with the impulsive unloading process. Copyright 2005 by the American Geophysical Union.