A Wavelet Approach to the Analysis of Auroral Electrojet (AE) Index.

The Auroral Electrojet (AE) index, introduced to track the global high-latitude geomagnetic activity mainly during magnetospheric substorms, has been widely studied as a global descriptor of the nonlinear and complex dynamics of the magnetosphere in response to solar-wind changes. However, it is nowadays well known that AE-index is mainly representative of two different processes: i) the enhancement of convection directly driven by solar-wind; ii) the magnetotail impulsive unloading (Rostoker et al., 1987; Kamide & Kokubun, 1996). Here, we approach to the two different processes by using some wavelet based techniques: the Local Intemittency Measure (LIM) analysis, and the Local Wavelet Bicoherence. By means of this two wavelet techniques, we will shown how the impulsive unloading component has a coherent intermittent character.