Infrasound from lightning and sprites

Abstract

Thunder properties and mechanisms have been mostly studied between 20 and 40 years ago. Infrasonic signal (frequency lower than 20 Hz), also called infrasound, has been measured in parallel to acoustic signal when lightning occur. Recent technical developments and new interest to infrasound revive research about thunder. A European measurement campaign, dedicated to sprite research, has been organised in 2005. This paper shows new results about descriptions of infrasound from lightning: maximum distance from which this kind of infrasound can be detected, infrasound frequency spectrum from 0.1 to 10 Hz completing previous ones acquired above 1 Hz. More recently, it has been shown that also sprites produce infrasound. Three-dimensional locations of infrasound sources associated to infrasound from sprites are calculated using only infrasound characteristic when sprites are close to an infrasound station. © Springer Science+Business Media B.V. 2009.