“…We discuss this in the context of a fractional Lévy motion (fLm) model where the noise is additive [ Samorodnitsky and Taqqu , 1994; Embrechts and Maejima , 2002; Calvo et al , 2009; Watkins et al , 2009], sometimes called linear fractional stable motion, which has been proposed as a model for the Akasofu ε parameter [ Watkins et al , 2005] and is considered an archetype of a dependent heavy‐tailed process in the mathematical theory of stochastic processes. In particular, in space physics Lévy motions have been used to model, e.g., magnetic field line transport [ Pommois et al , 1998], fluctuations in various solar wind parameters [ Hnat et al , 2003a; Bruno et al , 2004; Zaslavsky et al , 2008] and auroral indices [ Watkins et al , 2005; Zaslavsky et al , 2008] making our analysis of general interest.…”