ABSTRACT. The waiting time distribution for solar flares has been considered. Using Geostationary Operational Environmental Satellite X-ray data, we show that a local Poisson hypothesis for solar flares is not consistent with observations, while the observed distribution is well reproduced by a Lévy function, which displays asymptotically a power-law tail. The origin of the observed waiting time distribution is then attributed to the fact that the physical process underlying solar flares is statistically self-similar in time and is characterized by a certain amount of "memory."

Subject headings: MHD; Sun: activity; Sun: corona; Sun: flares; cosmic rays

Print publication: Issue 2 (2001 July 10)
Received 2000 December 4, accepted for publication 2001 June 5
Published 2001 June 27